Acupuncture Analgesia for Surgery in Animals
SUMMARY
Surgical analgesia can be produced by methods involving peripheral or central stimulation, such as acupuncture (AP) analgesia (AA). The most common method is Electro-Acupuncture Analgesia (EAA), using a special electrostimulator attached to needles in AP points.
The major advantages of AA or EAA are its safety in high-risk patients and excellent post-operative pain relief, freedom from complications and enhanced healing which follows surgery under AA. The major disadvantages are the long induction period (10-40 minutes) and variable degrees of analgesia, even in skilled hands.
Many combinations of AP points can be used to induce EAA in large and small animals and there is no agreement on which combination is best for which operation. However, certain points have marked analgesic effects. They are LI04,11; TH08; PC06; points along the GV Channel; (BaiHui, WeiGan, TianPing, SanTai; ChihYi points); points between the digits (BoKoKu, InKoTen in dogs; second interdigital space in rabbits), certain Earpoints; the Root of the Ear; LU01; BL23,30; ST25,36,44; SP06; GB34; and X 35. Sometimes needles are inserted parallel to (or at both ends of) the incision, together with some of those points.
The choice of point combinations depends largely on the personal preference and experience of the operator. However, it is useful to consider the Channels in relation to the operation site and to choose points from (a) distant points on Channels whose superficial, deep, collateral or other branches pass through the operation site, plus (b) local points near the operation site, plus (c) points along nerves supplying the operation site or related to the operation site by spinal reflexes.
There is no agreement on the choice of stimulation parameters, although work by Toda et al, Matsumoto and others show that these can be critical. Further research in this area is needed.
The mechanisms of AA involve stimulation of peripheral sensory nerves, spinal cord and supraspinal areas (thalamus, midbrain and hypothalamus). Release of endorphin and serotonin activates a descending pain-inhibition mechanism. ACTH release assists healing. Extra-spinal and autonomic transmission may also be involved in AA mechanisms.
Stimulation-Produced Analgesia (SPA) and Transcutaneous Electro-Stimulation Analgesia (TESA) are closely allied with EAA and involve endorphin release. Vaginal Stimulation Analgesia (VSA) appears to use different mechanisms. Electro-restraint ("Stockstill") appears to be quite a different phenomenon and may have little analgesic effect.
Electro-Narcosis, Electro-Anaesthesia and Electro-Sleep (Cerebral Electro- Therapy) differ from the other techniques, as they cause unconsciousness during Electro-Stimulation (ES).
Combining AP and western concepts, as in combination anaesthesia, will lead to development of safer and more reliable methods of surgical anaesthesia.
INTRODUCTION
Acupuncture (AP) can be used to obtain pain relief in clinical disorders or as an alternative or complementary method of inducing pain control during surgical procedures.
AP analgesia (AA) is a misnomer. It should really be called AP hypoalgesia. It is a pain inhibition phenomenon caused by stimulation of peripheral nerves via certain AP points. The degree of pain inhibition may be complete or partial.
In vet surgery, the AA technique, if applied carefully, often is sufficient to allow surgery without the use of other anaesthetics. Consciousness is retained throughout the operation but many animals become slightly drowsy (as if slightly sedated) during and for a short time after AA stimulation. All other sensations (touch, traction, pressure, tickle etc) and reflexes (to sight or sound stimuli, fear, traction etc) are intact.
AA can be induced by simple AP (manual twirling of the needles) but it is more common to use electrical stimulation (ES) via the needles. In this case the technique is called Electro-AP analgesia (EAA).
In emergencies a slight degree of hypo-algesia can be obtained in humans and animals by heavy digital pressure over the correct AP/nerve points. This method may have application in time of war or national disasters, when anaesthetists and anaesthetics may not be available. AA also can be induced by other stimuli, such as injection or electro-static fields applied to the points. Since the late 1980s, research on uses of low-power (cold) Laser as an AA stimulus is ongoing, with some positive results. However, it is too early to attempt to assess that method.
Stimuli via the AA points are carried in the peripheral sensory nerves to the spinal cord. They reach the midbrain via the ascending spino-thalamic tracts. In the midbrain the ascending signals cause release of endorphin, serotonin and other neurotransmitters which activate a "descending inhibition mechanism" and prevent the "pain signals" from the surgical area from reaching the cerebral cortex. Thus, AA can be said to "close" various "pain gates" in the nervous system. These gates are thought to be located in the spinal cord, thalamus and possibly other areas. The result is that the human (and, presumably, the animal) patient can feel the knife, the touch and traction etc but does not "feel pain".
Stimulation-Produced-Analgesia (SPA): Since the 1970s, western researchers, working independently of the Chinese, found that various types of stimuli applied indirectly or directly to the nervous system can reduce or abolish clinical and operative pain. Transcutaneous Electro-Stimulation Analgesia (TESA) has been used in childbirth in the human female and is somewhat comparable to EAA. Dorsal Column Stimulation (DCS) of the spinal cord has been used in intractable pain in humans. ES via electrodes implanted in specific sites in human or animal brain can induce a high degree of analgesia, usually involving the entire body. Direct ES of human thalamic or spinal areas can abolish clinical pain. Vaginal stimulation (electrical or mechanical) can cause potent whole-body analgesia in rats.
SPA has some similarities to AA. The main difference between these methods is that SPA tends to cause "whole body" analgesia, whereas the area of analgesia is much more localised in AA and is related to the site of the AA stimulation.
This paper will discuss the following topics:
1. types of operation successfully done under AA
2. equipment and methods of restraint used
3. techniques in large and small animals
4. advantages and disadvantages of AA in animals
5. mechanisms of AA
6. other methods of SPA (vaginal stimulation analgesia, electro-restraint, electro-narcosis and electro-sleep)
Surgical analgesia can be produced by methods involving peripheral or central stimulation, such as acupuncture (AP) analgesia (AA). The most common method is Electro-Acupuncture Analgesia (EAA), using a special electrostimulator attached to needles in AP points.
The major advantages of AA or EAA are its safety in high-risk patients and excellent post-operative pain relief, freedom from complications and enhanced healing which follows surgery under AA. The major disadvantages are the long induction period (10-40 minutes) and variable degrees of analgesia, even in skilled hands.
Many combinations of AP points can be used to induce EAA in large and small animals and there is no agreement on which combination is best for which operation. However, certain points have marked analgesic effects. They are LI04,11; TH08; PC06; points along the GV Channel; (BaiHui, WeiGan, TianPing, SanTai; ChihYi points); points between the digits (BoKoKu, InKoTen in dogs; second interdigital space in rabbits), certain Earpoints; the Root of the Ear; LU01; BL23,30; ST25,36,44; SP06; GB34; and X 35. Sometimes needles are inserted parallel to (or at both ends of) the incision, together with some of those points.
The choice of point combinations depends largely on the personal preference and experience of the operator. However, it is useful to consider the Channels in relation to the operation site and to choose points from (a) distant points on Channels whose superficial, deep, collateral or other branches pass through the operation site, plus (b) local points near the operation site, plus (c) points along nerves supplying the operation site or related to the operation site by spinal reflexes.
There is no agreement on the choice of stimulation parameters, although work by Toda et al, Matsumoto and others show that these can be critical. Further research in this area is needed.
The mechanisms of AA involve stimulation of peripheral sensory nerves, spinal cord and supraspinal areas (thalamus, midbrain and hypothalamus). Release of endorphin and serotonin activates a descending pain-inhibition mechanism. ACTH release assists healing. Extra-spinal and autonomic transmission may also be involved in AA mechanisms.
Stimulation-Produced Analgesia (SPA) and Transcutaneous Electro-Stimulation Analgesia (TESA) are closely allied with EAA and involve endorphin release. Vaginal Stimulation Analgesia (VSA) appears to use different mechanisms. Electro-restraint ("Stockstill") appears to be quite a different phenomenon and may have little analgesic effect.
Electro-Narcosis, Electro-Anaesthesia and Electro-Sleep (Cerebral Electro- Therapy) differ from the other techniques, as they cause unconsciousness during Electro-Stimulation (ES).
Combining AP and western concepts, as in combination anaesthesia, will lead to development of safer and more reliable methods of surgical anaesthesia.
INTRODUCTION
Acupuncture (AP) can be used to obtain pain relief in clinical disorders or as an alternative or complementary method of inducing pain control during surgical procedures.
AP analgesia (AA) is a misnomer. It should really be called AP hypoalgesia. It is a pain inhibition phenomenon caused by stimulation of peripheral nerves via certain AP points. The degree of pain inhibition may be complete or partial.
In vet surgery, the AA technique, if applied carefully, often is sufficient to allow surgery without the use of other anaesthetics. Consciousness is retained throughout the operation but many animals become slightly drowsy (as if slightly sedated) during and for a short time after AA stimulation. All other sensations (touch, traction, pressure, tickle etc) and reflexes (to sight or sound stimuli, fear, traction etc) are intact.
AA can be induced by simple AP (manual twirling of the needles) but it is more common to use electrical stimulation (ES) via the needles. In this case the technique is called Electro-AP analgesia (EAA).
In emergencies a slight degree of hypo-algesia can be obtained in humans and animals by heavy digital pressure over the correct AP/nerve points. This method may have application in time of war or national disasters, when anaesthetists and anaesthetics may not be available. AA also can be induced by other stimuli, such as injection or electro-static fields applied to the points. Since the late 1980s, research on uses of low-power (cold) Laser as an AA stimulus is ongoing, with some positive results. However, it is too early to attempt to assess that method.
Stimuli via the AA points are carried in the peripheral sensory nerves to the spinal cord. They reach the midbrain via the ascending spino-thalamic tracts. In the midbrain the ascending signals cause release of endorphin, serotonin and other neurotransmitters which activate a "descending inhibition mechanism" and prevent the "pain signals" from the surgical area from reaching the cerebral cortex. Thus, AA can be said to "close" various "pain gates" in the nervous system. These gates are thought to be located in the spinal cord, thalamus and possibly other areas. The result is that the human (and, presumably, the animal) patient can feel the knife, the touch and traction etc but does not "feel pain".
Stimulation-Produced-Analgesia (SPA): Since the 1970s, western researchers, working independently of the Chinese, found that various types of stimuli applied indirectly or directly to the nervous system can reduce or abolish clinical and operative pain. Transcutaneous Electro-Stimulation Analgesia (TESA) has been used in childbirth in the human female and is somewhat comparable to EAA. Dorsal Column Stimulation (DCS) of the spinal cord has been used in intractable pain in humans. ES via electrodes implanted in specific sites in human or animal brain can induce a high degree of analgesia, usually involving the entire body. Direct ES of human thalamic or spinal areas can abolish clinical pain. Vaginal stimulation (electrical or mechanical) can cause potent whole-body analgesia in rats.
SPA has some similarities to AA. The main difference between these methods is that SPA tends to cause "whole body" analgesia, whereas the area of analgesia is much more localised in AA and is related to the site of the AA stimulation.
This paper will discuss the following topics:
1. types of operation successfully done under AA
2. equipment and methods of restraint used
3. techniques in large and small animals
4. advantages and disadvantages of AA in animals
5. mechanisms of AA
6. other methods of SPA (vaginal stimulation analgesia, electro-restraint, electro-narcosis and electro-sleep)
1. TYPES OF OPERATIONS UNDER AA
Since the mid 1970s, major surgery has been done in animals under AA as the sole analgesic agent in many countries in the West. These include France, Germany, Austria, Belgium, USA, Canada and Australia. Workers in Eastern countries such as China, Japan, Taiwan etc have used the method for many years. The animal species involved include horses, mules, donkeys, cattle, sheep, goats, pigs, monkeys, dogs, cats, rats, cavies, guinea pigs and mice.
Types of surgery successfully done in animals include: caesarean section, ovario-hysterectomy; gastric and intestinal surgery; nephrectomy; removal of mammary and skin tumours; surgery of the eye, ear, anal and vaginal region, limbs and teats; surgery on the lip, oesophagus, trachea, frontal sinuses; rumen; navel hernia repair; surgery on the bladder and urethra; orthopaedic surgery (bones, joints); removal of parotid and submaxillary glands; castration, orchidopexy, inguinal hernia. The late Dr. Westermayer's method for reposition of the prolapsed uterus has been mentioned already, as has AP therapy for the relief of dystocia. (See the paper on AP effects on the body's defence systems. See also the paper on the integration of AP into routine vet practice).
Experimental surgery under AA includes: pain responses to towel clips, incision, thermal and electrical stimuli; thoracotomy, laparotomy, limb and skin surgery.
2. EQUIPMENT AND METHODS OF RESTRAINT FOR AA
Equipment: Most AA is done using electrostimulation (ES) through needles in the correct points (Electro-AP analgesia = EAA). The choice of points will be discussed later. Many different types of electrostimulator are on the market. Some are made in China, others in Japan, USA, Canada, Europe and Australia etc.
The equipment should be strong, portable and battery-operated. It should have outputs for at least 8 electrodes. There is little standardization of equipment. Newer models for human use would be adequate for EAA in animals. It is safer to use models which deliver a bipolar waveform, (+) and (-), at each electrode. This prevents the development of serious electrolytic lesions which could arise if a monopolar waveform was used for long periods, as in prolonged surgery.
The Model 71-3 General Purpose Electro-AP Apparatus is suitable for AA as well as AP therapy. I had 8 teeth extracted and 8 teeth filled under EAA with the Model 71-3. I used mainly ChiaChe (ST06) plus Earlobe "Dental Analgesia Point" on the affected side. Needles were inserted 12-20 mm in the points. Voltage was increased slowly to maximum tolerance (anaesthesia mode, dense-disperse waveform). Occasionally adjustable waveform at 5-10 Hz was used. After 30 minutes of induction, the output was usually at a setting of 4-5 on a 10 point scale. When heavy needle-probing of the gum caused no pain, dentistry could begin. Dental fillings under EAA were uneventful except in deep root fillings. If "nerve pain" arose, turning up the voltage usually controlled it. Extraction was painless or caused minimal pain in 5/8 cases but 3/8 extractions caused moderate to severe pain but were completed without the use of drug analgesia. An impacted wisdom-tooth required 10 minutes of very strong rocking to remove it from its socket. There was rather severe pressure-pain with that attempt but I was able to tolerate it without asking for another anaesthetic. My dentist told me that most patients could not have had the tooth removed unless they had general anaesthesia.
In human patients, Caesarean section has been done in Japan using electro-static or electromagnetic fields around the hands and feet. The apparatus used does not appear to have been tested in Europe or America. Childbirth has been helped in 60-80% of women treated by transcutaneous ES analgesia (TESA) of the thoraco-lumbo-sacral region. The apparatus used was the Travisens, available from Dan Sjo Elektronik AB, Box 144-17224, Sundbyberg, Sweden. TESA does not appear to have been tested in animals.
Restraint for AA in animals: Surgery under AA requires adequate restraint because consciousness and all sensations and reflexes (except those of pain) are retained.
In large animals, operations under AA may be performed with the animal in the standing position or in dorsal, lateral or ventral recumbency, depending on the type of operation and whether or not the animal is quiet. Horses and nervous cattle should be knocked by ropes or a short-acting knock-down anaesthetic. Nervous animals may be given a tranquilliser i/v. Recumbent animals should be roped securely and an attendant should ensure that the head is kept down. A blindfold over the animal's eyes helps to avoid fright by visual stimuli. Unnecessary noise, movement and fuss should be kept to a minimum.
The standing position may be used for surgery in quiet cattle. An attendant may hold the nose and the animal should be restrained in a suitable cattle crate, or ropes may be used through rings in the wall to keep the animal in one position. Kicking may be prevented by the usual methods as applied in operations under local anaesthesia.
Small animals are normally operated on in lateral, dorsal or ventral recumbency. If a special operation-harness is not available they are restrained by tying bandages from the hocks and elbows to suitable anchor-points on the operating table. Dogs are excellent subjects for AA but it is advisable to tie a tape bandage around the jaws to prevent biting. It helps if the owner or an attendant talks to the dog and comforts the animal from time to time during surgery. Cats are difficult animals to handle and some vets who have tried AA in cats have ceased to use the technique in this species.
3. AA TECHNIQUES IN LARGE AND SMALL ANIMALS
Electro-AP analgesia (EAA) is the most common method used. When the animal is properly restrained, AP needles are placed to the correct depth in the AA points related to the operation site. The stimulator is checked to ensure that the power switch is off. The output leads are then connected to the needles. Do not connect the leads from one output across the thoracic or posterior cervical region. This is especially advisable if the instrument uses (+) and (-) electrodes. In this case the correct connection would be as in the diagram on the next page. An output circuit placed across the thorax may interfere with cardiac function and may, on rare occasions, cause cardiac arrest.
Tape or suture the needles firmly in position. Otherwise, they are liable to become dislodged by muscle twitches induced by the stimulation, or by struggling in nervous animals. When the needles are in position, the output controls are checked to ensure they are set at zero. Attach the leads and turn on the power switch. Turn up the output controls slowly until the needles begin to twitch in time with the frequency of the stimulator. Increase the output voltage from each control to the maximum tolerance of the patient. At that point, the animal indicates a degree of discomfort or pain (restlessness, defensive reaction, struggling, vocalisation etc). Reduce the output to a "strong but acceptable level" (that which can be tolerated without obvious discomfort). Excessive stimulation reduces the EAA effect and to weak a stimulus may induce little or no analgesia.
Note: A needle can not twitch unless it is embedded in reactive muscle. As long as one of a pair is twitching, the paired needle is also receiving a similar stimulus. Needles may not twitch in points such as GV26. If output voltage is too high at such points, the animal will indicate discomfort. In that case, reduce the output to the tolerance of the patient.
Every 5 minutes or so, after switch-on, the operation site is tested for analgesia using rat-tooth forceps, towel clip, clamp or pin prick. Initially, full sensitivity to pain is present, as indicated by local muscle twitch or guarding, vocalisation or defence reactions/struggling. After 5-10 minutes, the response to pain stimulus decreases. After 20-40 minutes, in successful cases, the animal makes no response to strong pain stimuli in and around the operation site. The operation may then commence.
Pain stimuli may exceed the hypoalgesia (thereby inducing pain response by the animal) at certain stages of the operation, especially during incision and suturing of the skin, serosa (peritoneum, pleura etc) and incision of periosteum and nerves. During these stages of the operation the frequency or output voltage should be increased. This is normally sufficient to counteract the pain. Occasionally (in those animals which respond poorly to AA) it may be necessary to use small volumes of local anaesthetic injection or spray at these stages.
In the first few minutes after stimulation begins it is usual for the animal to show a mild stress reaction (dilated pupils, increased blood pressure, faster respiration and heart rate). These quickly return to normal or near normal levels, and should remain at this level during the operation. Studies of EEG patterns in animals under AA indicate that brain waves are in the alpha range (8-13 cycle per second) i.e., similar to those of drowsiness or light sleep. However, the animals are still conscious and can eat or drink and (in dogs) wag the tail if petted by someone they know. Because sight and hearing are unaffected (pupil reflex is also intact), unnecessary noise should be avoided and a blindfold may be desirable. Pupillary dilation and salivation occurs in some animals. If salivation is excessive or retching/vomiting occurs, this usually indicates that excessive traction on mesentery/internal organs is the cause. This may be partly counteracted by increase in frequency or output of the AA stimuli.
The choice of points for AA depends on the species of animal, the operation site and personal preference/experience. Many different combinations are effective and there is no one combination which is agreed by all authors. In general, points are chosen according to Channel theory of human AP.
Classic AP teaches that the Channels have a superficial course (Jing, from the first to the last point on the Channel), a deep course (going to the organ of the Channel and possibly linking to other organs and deep regions), a collateral course (Luo, which links up with its Mate Channel) and other connections linking to every part of the body, interior and exterior. For instance, the LV Channel (big toe to chest, under the nipple) also sends a branch to the eye. (Discussion of the deep, collateral and other connections is not included in this seminar. These concepts are covered in certain classic texts, such as those of Van Nghi and Mann).
Thus in eye operations, a LV point might be included; in tongue operations a HT point might be included; in ear and bone operations a KI point might be included. In man, AA sometimes uses Earpoints for the organ or region being incised, i.e. for lung operations, Earpoint LU; for appendectomy, Earpoint LI, or Appendix etc.
The general rule is to use Local Points (near the operation site). As will be seen from some point prescriptions below, this rule is not always obeyed. Other workers pay particular attention to the points or nerves supplying the operation site, or related to it. In human EAA, same workers add two needles, one on each side of the incision. The diagram shows 2 needles, 25 cm long, buried parallel to the incision:
Since the mid 1970s, major surgery has been done in animals under AA as the sole analgesic agent in many countries in the West. These include France, Germany, Austria, Belgium, USA, Canada and Australia. Workers in Eastern countries such as China, Japan, Taiwan etc have used the method for many years. The animal species involved include horses, mules, donkeys, cattle, sheep, goats, pigs, monkeys, dogs, cats, rats, cavies, guinea pigs and mice.
Types of surgery successfully done in animals include: caesarean section, ovario-hysterectomy; gastric and intestinal surgery; nephrectomy; removal of mammary and skin tumours; surgery of the eye, ear, anal and vaginal region, limbs and teats; surgery on the lip, oesophagus, trachea, frontal sinuses; rumen; navel hernia repair; surgery on the bladder and urethra; orthopaedic surgery (bones, joints); removal of parotid and submaxillary glands; castration, orchidopexy, inguinal hernia. The late Dr. Westermayer's method for reposition of the prolapsed uterus has been mentioned already, as has AP therapy for the relief of dystocia. (See the paper on AP effects on the body's defence systems. See also the paper on the integration of AP into routine vet practice).
Experimental surgery under AA includes: pain responses to towel clips, incision, thermal and electrical stimuli; thoracotomy, laparotomy, limb and skin surgery.
2. EQUIPMENT AND METHODS OF RESTRAINT FOR AA
Equipment: Most AA is done using electrostimulation (ES) through needles in the correct points (Electro-AP analgesia = EAA). The choice of points will be discussed later. Many different types of electrostimulator are on the market. Some are made in China, others in Japan, USA, Canada, Europe and Australia etc.
The equipment should be strong, portable and battery-operated. It should have outputs for at least 8 electrodes. There is little standardization of equipment. Newer models for human use would be adequate for EAA in animals. It is safer to use models which deliver a bipolar waveform, (+) and (-), at each electrode. This prevents the development of serious electrolytic lesions which could arise if a monopolar waveform was used for long periods, as in prolonged surgery.
The Model 71-3 General Purpose Electro-AP Apparatus is suitable for AA as well as AP therapy. I had 8 teeth extracted and 8 teeth filled under EAA with the Model 71-3. I used mainly ChiaChe (ST06) plus Earlobe "Dental Analgesia Point" on the affected side. Needles were inserted 12-20 mm in the points. Voltage was increased slowly to maximum tolerance (anaesthesia mode, dense-disperse waveform). Occasionally adjustable waveform at 5-10 Hz was used. After 30 minutes of induction, the output was usually at a setting of 4-5 on a 10 point scale. When heavy needle-probing of the gum caused no pain, dentistry could begin. Dental fillings under EAA were uneventful except in deep root fillings. If "nerve pain" arose, turning up the voltage usually controlled it. Extraction was painless or caused minimal pain in 5/8 cases but 3/8 extractions caused moderate to severe pain but were completed without the use of drug analgesia. An impacted wisdom-tooth required 10 minutes of very strong rocking to remove it from its socket. There was rather severe pressure-pain with that attempt but I was able to tolerate it without asking for another anaesthetic. My dentist told me that most patients could not have had the tooth removed unless they had general anaesthesia.
In human patients, Caesarean section has been done in Japan using electro-static or electromagnetic fields around the hands and feet. The apparatus used does not appear to have been tested in Europe or America. Childbirth has been helped in 60-80% of women treated by transcutaneous ES analgesia (TESA) of the thoraco-lumbo-sacral region. The apparatus used was the Travisens, available from Dan Sjo Elektronik AB, Box 144-17224, Sundbyberg, Sweden. TESA does not appear to have been tested in animals.
Restraint for AA in animals: Surgery under AA requires adequate restraint because consciousness and all sensations and reflexes (except those of pain) are retained.
In large animals, operations under AA may be performed with the animal in the standing position or in dorsal, lateral or ventral recumbency, depending on the type of operation and whether or not the animal is quiet. Horses and nervous cattle should be knocked by ropes or a short-acting knock-down anaesthetic. Nervous animals may be given a tranquilliser i/v. Recumbent animals should be roped securely and an attendant should ensure that the head is kept down. A blindfold over the animal's eyes helps to avoid fright by visual stimuli. Unnecessary noise, movement and fuss should be kept to a minimum.
The standing position may be used for surgery in quiet cattle. An attendant may hold the nose and the animal should be restrained in a suitable cattle crate, or ropes may be used through rings in the wall to keep the animal in one position. Kicking may be prevented by the usual methods as applied in operations under local anaesthesia.
Small animals are normally operated on in lateral, dorsal or ventral recumbency. If a special operation-harness is not available they are restrained by tying bandages from the hocks and elbows to suitable anchor-points on the operating table. Dogs are excellent subjects for AA but it is advisable to tie a tape bandage around the jaws to prevent biting. It helps if the owner or an attendant talks to the dog and comforts the animal from time to time during surgery. Cats are difficult animals to handle and some vets who have tried AA in cats have ceased to use the technique in this species.
3. AA TECHNIQUES IN LARGE AND SMALL ANIMALS
Electro-AP analgesia (EAA) is the most common method used. When the animal is properly restrained, AP needles are placed to the correct depth in the AA points related to the operation site. The stimulator is checked to ensure that the power switch is off. The output leads are then connected to the needles. Do not connect the leads from one output across the thoracic or posterior cervical region. This is especially advisable if the instrument uses (+) and (-) electrodes. In this case the correct connection would be as in the diagram on the next page. An output circuit placed across the thorax may interfere with cardiac function and may, on rare occasions, cause cardiac arrest.
Tape or suture the needles firmly in position. Otherwise, they are liable to become dislodged by muscle twitches induced by the stimulation, or by struggling in nervous animals. When the needles are in position, the output controls are checked to ensure they are set at zero. Attach the leads and turn on the power switch. Turn up the output controls slowly until the needles begin to twitch in time with the frequency of the stimulator. Increase the output voltage from each control to the maximum tolerance of the patient. At that point, the animal indicates a degree of discomfort or pain (restlessness, defensive reaction, struggling, vocalisation etc). Reduce the output to a "strong but acceptable level" (that which can be tolerated without obvious discomfort). Excessive stimulation reduces the EAA effect and to weak a stimulus may induce little or no analgesia.
Note: A needle can not twitch unless it is embedded in reactive muscle. As long as one of a pair is twitching, the paired needle is also receiving a similar stimulus. Needles may not twitch in points such as GV26. If output voltage is too high at such points, the animal will indicate discomfort. In that case, reduce the output to the tolerance of the patient.
Every 5 minutes or so, after switch-on, the operation site is tested for analgesia using rat-tooth forceps, towel clip, clamp or pin prick. Initially, full sensitivity to pain is present, as indicated by local muscle twitch or guarding, vocalisation or defence reactions/struggling. After 5-10 minutes, the response to pain stimulus decreases. After 20-40 minutes, in successful cases, the animal makes no response to strong pain stimuli in and around the operation site. The operation may then commence.
Pain stimuli may exceed the hypoalgesia (thereby inducing pain response by the animal) at certain stages of the operation, especially during incision and suturing of the skin, serosa (peritoneum, pleura etc) and incision of periosteum and nerves. During these stages of the operation the frequency or output voltage should be increased. This is normally sufficient to counteract the pain. Occasionally (in those animals which respond poorly to AA) it may be necessary to use small volumes of local anaesthetic injection or spray at these stages.
In the first few minutes after stimulation begins it is usual for the animal to show a mild stress reaction (dilated pupils, increased blood pressure, faster respiration and heart rate). These quickly return to normal or near normal levels, and should remain at this level during the operation. Studies of EEG patterns in animals under AA indicate that brain waves are in the alpha range (8-13 cycle per second) i.e., similar to those of drowsiness or light sleep. However, the animals are still conscious and can eat or drink and (in dogs) wag the tail if petted by someone they know. Because sight and hearing are unaffected (pupil reflex is also intact), unnecessary noise should be avoided and a blindfold may be desirable. Pupillary dilation and salivation occurs in some animals. If salivation is excessive or retching/vomiting occurs, this usually indicates that excessive traction on mesentery/internal organs is the cause. This may be partly counteracted by increase in frequency or output of the AA stimuli.
The choice of points for AA depends on the species of animal, the operation site and personal preference/experience. Many different combinations are effective and there is no one combination which is agreed by all authors. In general, points are chosen according to Channel theory of human AP.
Classic AP teaches that the Channels have a superficial course (Jing, from the first to the last point on the Channel), a deep course (going to the organ of the Channel and possibly linking to other organs and deep regions), a collateral course (Luo, which links up with its Mate Channel) and other connections linking to every part of the body, interior and exterior. For instance, the LV Channel (big toe to chest, under the nipple) also sends a branch to the eye. (Discussion of the deep, collateral and other connections is not included in this seminar. These concepts are covered in certain classic texts, such as those of Van Nghi and Mann).
Thus in eye operations, a LV point might be included; in tongue operations a HT point might be included; in ear and bone operations a KI point might be included. In man, AA sometimes uses Earpoints for the organ or region being incised, i.e. for lung operations, Earpoint LU; for appendectomy, Earpoint LI, or Appendix etc.
The general rule is to use Local Points (near the operation site). As will be seen from some point prescriptions below, this rule is not always obeyed. Other workers pay particular attention to the points or nerves supplying the operation site, or related to it. In human EAA, same workers add two needles, one on each side of the incision. The diagram shows 2 needles, 25 cm long, buried parallel to the incision:
Some workers prefer to use AP stimulation at a low frequency and to increase the frequency gradually during the induction period. For instance, Ishizaki recommended a frequency of 10 Hz, increasing to 30-50 Hz at the start of operation in dogs. Other operators prefer faster or slower frequencies. For instance, Matsumoto found that frequencies of less than 200 or greater than 10000 Hz were less satisfactory in rabbits than frequencies within this range.
Points used in AA in animals: Many different workers have used many different combinations of points in various animal species. Examples of point combinations are given later. The following table lists the points by authors whose work is discussed later. These points are similar in position to points of the same name and code in HUMAN AP.
Other points used in AA in animals are:
1. On the GV Channel:
3. ChihYi Points are on the course of the GV Channel but are not classic GV points. They have been described recently in relation to human AA. The main ones used in vet AA are over the dorsal spines of vertebrae: Dorsal 3,5,6,11 and Lumbar 1.
4. Para-incisional points are not often used in vet AA, as the needles may impede access to the site.
5. ChiehKou points. These are also described in recent human texts. They are local points at each end of the incision.
Points used in AA in animals: Many different workers have used many different combinations of points in various animal species. Examples of point combinations are given later. The following table lists the points by authors whose work is discussed later. These points are similar in position to points of the same name and code in HUMAN AP.
Other points used in AA in animals are:
1. On the GV Channel:
- BaiHui: In the dorsal midline of the lumbo-sacral space, depth 3-5 cm in horse/ox, to react the dura mater. There is no direct equivalent in human AP.
- WeiGan: In the dorsal midline between coccygeal vertebrae 2-3. Depth 1-1.5 cm in horse/ox. There is no direct equivalent in human AP.
- TianPing : In the dorsal midline, in the thoraco-lumbar space. Depth 2-4 cm in horse/ox, at 90 degrees to the surface). There is no direct equivalent in human AP.
- SanTai: In the dorsal midline, between the spines of thoracic vertebrae 4-5 (some texts say T5-6). Depth 6-8 cm antero-ventrally in horse/ox. SanTai is equivalent to GV11 (Shen Tao).
3. ChihYi Points are on the course of the GV Channel but are not classic GV points. They have been described recently in relation to human AA. The main ones used in vet AA are over the dorsal spines of vertebrae: Dorsal 3,5,6,11 and Lumbar 1.
4. Para-incisional points are not often used in vet AA, as the needles may impede access to the site.
5. ChiehKou points. These are also described in recent human texts. They are local points at each end of the incision.
Points used in AA or EAA: The most commonly used points are UNDERLINED:
6. Points described by Japanese workers also include: InKoTen (between metacarpal bones 3 and 4 in small animals); BoKoKu (between metatarsal bones 3 and 4 in small animals); GeiKo (on the lateral margin of the naso-labial fold in mice and rats); unnamed point (in the second interdigital space in rabbits on the hindlimb (this may correspond with ST44 (NeiTing)). The Japanese points do not appear to have equivalents in Chinese human or vet texts.
EXAMPLES OF POINT SELECTION IN LARGE ANIMALS: Points used for AA in horses and cattle.
a. Horse: LU01 (ChungFu) with TH08 (SanYangLo penetrating to YieYen) was one of the first combinations used in large animals ln China (Niboyet). It was used especially in thoracic and abdominal surgery. A needle is inserted to a depth of 3-5 cm in LU01 (behind the shoulder in the second intercostal space). A second needle is inserted at TH08 (about 1 handsbreadth below the elbow, on the lateral side). It is driven medially and downwards behind the radius/ulna to reach YieYen (PC04.5), just under the skin above the "chestnut". The needles are inserted on the uppermost limb (horse in lateral recumbency).
b. Horse: In navel hernia operation, Humphries used 4 needles: Set 1: LU01 (positive) with TH08 penetrating to PC04.5 (negative). Set 2: SP06 (positive) with ST36 (negative). The frequency was 200 Hz, square wave, altered to spike wave during surgery. This horse was very ill and was a high anaesthetic risk, yet the operation went perfectly and no signs of pain were detected at any stage in the operation, which lasted 4 hours.
c. Horse or ox: Sun et al used traditional Chinese vet AP points on hundreds of large animals (horses and cattle).
Points for abdominal, vaginal and hindlimb operations were : BaiHui (main point) plus WeiGan (secondary point) plus TianPing (minor point). In chest operations, they used SanTai. To each of these points they added points on or near the spinal nerves supplying the operation site + points from the attached charts nearest the incision site.
d. Cattle: Kothbauer did many Caesarian sections in cows using EAA. In his first 2 cases he used LV14 (8th intercostal space, at a level with the shoulder joint) with BL30, both points on the left side. EAA was given at 40 Hz, output causing marked muscle twitch. Induction time was 20 minutes.
e. Ox, pig: In Japan, the Akita Veterinary AP Research Unit tested many point combinations (including the classic LU01 with TH08 penetrating to PC04.5). They concluded that the best effective points in cattle and pigs were Tenpei (TianPing) and Hyahai (BaiHui). These points are located in the midline at the thoraco-lumbar space and the lumbo-sacral space, as in combinations (c) above. The depth of needle insertion would be similar to that in combination (c) above (the Chinese combination), i.e. penetrating almost to the dura mater. They used 30 Hz. Voltage (output) was increased if the animals were recumbent.
EXAMPLES OF POINT SELECTION IN SMALL ANIMALS
Dog:
a. Kitazawa (Gifu Veterinary Faculty, Japan) did dozens of operations in which he compared the efficiency of various point combinations. The best combination for surgery in all areas was BL23 bilateral. Equally good was SP06 bilateral, but EAA of this point occasionally caused convulsions.
The next best combination was 8 needles, one in each point on each limb: LI11 plus InKoTen (Japanese point, between metacarpals 3 and 4) plus ST36 plus BoKoKu (Japanese point, between metatarsals 3 and 4); 4 points, bilateral = 8 needles.
He also examined other combinations but his preference was for 2 needles in BL23 (left and right). This point is paravertebral between the transverse processes of lumbar vertebrae 2-3.
b. The late Dr. Ishizaki (Japan) did over 50 major operations in dogs with 95% success. Unfortunately, he had no simple combination of points, as he chose points according to Channel Theory and also points near the operation site. However, in general, for operations on the head, neck, thorax and upper limb he used points PC06 and TH08 bilateral, with the needles penetrating completely through the limb (in one side, out the other) behind the radius and ulna. For operations on the abdomen and hindlimbs, he used SP06 (penetrating completely through the limb) and ST36. For anal surgery he added points lateral to the anus.
c. In a large series of toxic pyometra cases, Arambarri and Cazieux in the Toulouse Vet School used AA at points SP06; ST36,25; plus para-incisional needles for ovariohysterectomy. Not one case died and all recovered uneventfully. EAA was given at 2.5 Hz, rising to 3.5-4.5 Hz during operation. Manual AA was also successful.
d. Ralston reported uneventful removal of bladder calculi and Caesarean section in high-risk dogs using needles bilaterally in LI04 and ST36 (positive poles) and SP06, LI11 (negative poles).
e. O'Boyle and Vajda used SP06 and ST36 (bilateral) in 15 dogs. The operations (all of which were done successfully without other anaesthetics) included Caesarean section, removal of abscessed mammary tumour, splenectomy, gastric and intestinal surgery and ovariohysterectomy. They used 125 Hz, square wave, 2 seconds on/2 seconds off.
Monkeys:
Many combinations can be used in monkeys. The ones listed below are only a few of the combinations listed in texts on human EAA.
Vierck applied an electrical pain stimulus to the gastrocnemius area of monkeys. Bilateral electrostimulation of ST36 gave marked hypo-algesic effects. He used 200 Hz monophasic square wave, 0.5 msec. Monkeys respond similarly to man in many aspects of AP. Thus one should expect the following points to be effective:
Cats:
The cat is difficult to work with and resents needles placed in the feet. Lambardt used EAA at 2.5 Hz on 4 cats (3 ovariohysterectomies, 1 Caesarean section). His points were: ST36; BL49; LU01; TH08 (bilateral). The results were not satisfactory and he noted much struggling. Three assistants were needed to restrain the animals! He concluded that cats are not the best subjects for EAA.
Other workers have used cats very successfully in experimental work on EAA (confirmation that the limbic and cortical potentials elicited by pain stimuli were suppressed by EAA) and Still (1987) claimed very good surgical analgesia in cats, using EAA at pre- and post-auricular points, plus GV06b, BL23,23a,24, lumbo-sacral space (GV03a) and SP06. The choice of points and frequency of stimulation are important to good success, especially in cats.
Rabbits:
Matsumoto reported the best analgesia from ES of a single needle placed to a depth of 3 cm in the second interdigital space. The negative electrode was a needle placed in the thigh muscles or at the vertex of the head. This technique at 200-10000 Hz sine wave gave powerful analgesia of ventral aspects of the neck, upper limb, thorax, abdomen and thigh. The analgesic effect crossed the midline, i.e. a left needle gave left and right analgesia. Chinese workers have also used AA on Earpoints alone for abdominal surgery in rabbits.
Rats:
Toda et al have done many years of research with EAA in rats to study the mechanisms of EAA in the treatment of dental pain and as a preparation for dental surgery. They tested various points and concluded that the most effective points for dental analgesia were LI04 (bilateral) or needle cathode at GeiKo (Japanese points on the lateral margin of the naso-labial fold) and a 3 x 4 cm silver plate anode placed on the centre of the abdomen. The GeiKo point was stimulated at 45 Hz, 5 msec, until the nose twitched in frequency with the stimulator. Analgesia occurred on both sides of the mouth from stimulation of GeiKo on one side but was better on the side opposite to the needle.
In the experiments with LI04, they did extensive trials to examine various frequencies (0.5, 1,10,30,45,100,150,300,500,1000 Hz). They found that some analgesia occurred at all frequencies from 0.5 to 500 Hz but the best analgesia was given by frequencies between 30 and 150 Hz. 1000 Hz was unsatisfactory. Induction was about 15 minutes. They also tested stimulation patterns using pulse durations between 0.1-5.0 msec. The pulse duration had little effect on efficiency of analgesia.
Mice:
EAA at LI04, square wave, 4 Hz, 0.1 msec, for 20 minutes. Output level was adjusted until muscular contraction occurred and was increased to just below the level which caused the mice to vocalise (squeak). Under experimental conditions this had analgesic effects on the nose. The effects were reversed by opiate antagonists (levo-naloxone, naltrexone, cyclazine, diprenorphine) but not by dextro-naloxone (which has little opiate- antagonist effect) (Cheng & Pomeranz 1980).
Dogs, cats, monkeys, cavies and rats:
Lynd in the San Antonio Medical School, Texas, experimented with a "standard surgical incision and suturing" applied to the upper lateral abdomen. A lateral incision through skin and muscle layers was used in all animals. He used only simple insertion of needles (no ES) in the following points GB01; TH23; HT05; BL23,22; KI06. All points were needled bilaterally and the needles were left in position. When the animal lost its reaction to pinprick etc, the incision was made and was then sutured. He reported excellent analgesia but gave no statistics.
EXAMPLES OF POINT SELECTION IN LARGE ANIMALS: Points used for AA in horses and cattle.
a. Horse: LU01 (ChungFu) with TH08 (SanYangLo penetrating to YieYen) was one of the first combinations used in large animals ln China (Niboyet). It was used especially in thoracic and abdominal surgery. A needle is inserted to a depth of 3-5 cm in LU01 (behind the shoulder in the second intercostal space). A second needle is inserted at TH08 (about 1 handsbreadth below the elbow, on the lateral side). It is driven medially and downwards behind the radius/ulna to reach YieYen (PC04.5), just under the skin above the "chestnut". The needles are inserted on the uppermost limb (horse in lateral recumbency).
b. Horse: In navel hernia operation, Humphries used 4 needles: Set 1: LU01 (positive) with TH08 penetrating to PC04.5 (negative). Set 2: SP06 (positive) with ST36 (negative). The frequency was 200 Hz, square wave, altered to spike wave during surgery. This horse was very ill and was a high anaesthetic risk, yet the operation went perfectly and no signs of pain were detected at any stage in the operation, which lasted 4 hours.
c. Horse or ox: Sun et al used traditional Chinese vet AP points on hundreds of large animals (horses and cattle).
Points for abdominal, vaginal and hindlimb operations were : BaiHui (main point) plus WeiGan (secondary point) plus TianPing (minor point). In chest operations, they used SanTai. To each of these points they added points on or near the spinal nerves supplying the operation site + points from the attached charts nearest the incision site.
d. Cattle: Kothbauer did many Caesarian sections in cows using EAA. In his first 2 cases he used LV14 (8th intercostal space, at a level with the shoulder joint) with BL30, both points on the left side. EAA was given at 40 Hz, output causing marked muscle twitch. Induction time was 20 minutes.
e. Ox, pig: In Japan, the Akita Veterinary AP Research Unit tested many point combinations (including the classic LU01 with TH08 penetrating to PC04.5). They concluded that the best effective points in cattle and pigs were Tenpei (TianPing) and Hyahai (BaiHui). These points are located in the midline at the thoraco-lumbar space and the lumbo-sacral space, as in combinations (c) above. The depth of needle insertion would be similar to that in combination (c) above (the Chinese combination), i.e. penetrating almost to the dura mater. They used 30 Hz. Voltage (output) was increased if the animals were recumbent.
EXAMPLES OF POINT SELECTION IN SMALL ANIMALS
Dog:
a. Kitazawa (Gifu Veterinary Faculty, Japan) did dozens of operations in which he compared the efficiency of various point combinations. The best combination for surgery in all areas was BL23 bilateral. Equally good was SP06 bilateral, but EAA of this point occasionally caused convulsions.
The next best combination was 8 needles, one in each point on each limb: LI11 plus InKoTen (Japanese point, between metacarpals 3 and 4) plus ST36 plus BoKoKu (Japanese point, between metatarsals 3 and 4); 4 points, bilateral = 8 needles.
He also examined other combinations but his preference was for 2 needles in BL23 (left and right). This point is paravertebral between the transverse processes of lumbar vertebrae 2-3.
b. The late Dr. Ishizaki (Japan) did over 50 major operations in dogs with 95% success. Unfortunately, he had no simple combination of points, as he chose points according to Channel Theory and also points near the operation site. However, in general, for operations on the head, neck, thorax and upper limb he used points PC06 and TH08 bilateral, with the needles penetrating completely through the limb (in one side, out the other) behind the radius and ulna. For operations on the abdomen and hindlimbs, he used SP06 (penetrating completely through the limb) and ST36. For anal surgery he added points lateral to the anus.
c. In a large series of toxic pyometra cases, Arambarri and Cazieux in the Toulouse Vet School used AA at points SP06; ST36,25; plus para-incisional needles for ovariohysterectomy. Not one case died and all recovered uneventfully. EAA was given at 2.5 Hz, rising to 3.5-4.5 Hz during operation. Manual AA was also successful.
d. Ralston reported uneventful removal of bladder calculi and Caesarean section in high-risk dogs using needles bilaterally in LI04 and ST36 (positive poles) and SP06, LI11 (negative poles).
e. O'Boyle and Vajda used SP06 and ST36 (bilateral) in 15 dogs. The operations (all of which were done successfully without other anaesthetics) included Caesarean section, removal of abscessed mammary tumour, splenectomy, gastric and intestinal surgery and ovariohysterectomy. They used 125 Hz, square wave, 2 seconds on/2 seconds off.
Monkeys:
Many combinations can be used in monkeys. The ones listed below are only a few of the combinations listed in texts on human EAA.
Vierck applied an electrical pain stimulus to the gastrocnemius area of monkeys. Bilateral electrostimulation of ST36 gave marked hypo-algesic effects. He used 200 Hz monophasic square wave, 0.5 msec. Monkeys respond similarly to man in many aspects of AP. Thus one should expect the following points to be effective:
- Dental surgery: LI04 plus ST06 or Ear Root (Dental) point plus ST06
- Oral plus lip surgery: ST44 plus LI04 (Jacobs: 15 minutes at 100 Hz gave excellent results).
- Thoracic surgery: TH08 penetrating to PC04.5 +/- PC06 (or) TH05 penetrating to PC06 (or) LI14; TH14 (or) LI04; PC06 (or) LI10; TH17
- Abdominal surgery: SP06; ST36 (or) ChihYi points (main point in midline at vertebra T6 plus secondary point at T3. Upper abdominal surgery: add point at T5; lower abdomen: add point at T11).
- Upper limb surgery: Choose points from LI04,11,15,17,18; LU02,5,10; TH03,4,13; PC04,6; HT03, depending on site of surgery, Channels near the operation site and the nerve supply.
- Lower limb surgery: Choose points from SP03,4,6; GB30,34,36,38,39,40,43; LV02,03,05,06; KI03; ST36,40,44; BL40,49,54,57,59,60; ChihYi points (main point in midline over the 6th thoracic vertebra and secondary point over 1st lumbar vertebra; X 35 in region lumbar 1 to sacrum 2, depending on site of surgery, Channels near site and nerve supply.
- Dorso-lumbar surgery: LI04; TH05 plus ChiehKou (local points at each end of the incision); ChihYi points.
Cats:
The cat is difficult to work with and resents needles placed in the feet. Lambardt used EAA at 2.5 Hz on 4 cats (3 ovariohysterectomies, 1 Caesarean section). His points were: ST36; BL49; LU01; TH08 (bilateral). The results were not satisfactory and he noted much struggling. Three assistants were needed to restrain the animals! He concluded that cats are not the best subjects for EAA.
Other workers have used cats very successfully in experimental work on EAA (confirmation that the limbic and cortical potentials elicited by pain stimuli were suppressed by EAA) and Still (1987) claimed very good surgical analgesia in cats, using EAA at pre- and post-auricular points, plus GV06b, BL23,23a,24, lumbo-sacral space (GV03a) and SP06. The choice of points and frequency of stimulation are important to good success, especially in cats.
Rabbits:
Matsumoto reported the best analgesia from ES of a single needle placed to a depth of 3 cm in the second interdigital space. The negative electrode was a needle placed in the thigh muscles or at the vertex of the head. This technique at 200-10000 Hz sine wave gave powerful analgesia of ventral aspects of the neck, upper limb, thorax, abdomen and thigh. The analgesic effect crossed the midline, i.e. a left needle gave left and right analgesia. Chinese workers have also used AA on Earpoints alone for abdominal surgery in rabbits.
Rats:
Toda et al have done many years of research with EAA in rats to study the mechanisms of EAA in the treatment of dental pain and as a preparation for dental surgery. They tested various points and concluded that the most effective points for dental analgesia were LI04 (bilateral) or needle cathode at GeiKo (Japanese points on the lateral margin of the naso-labial fold) and a 3 x 4 cm silver plate anode placed on the centre of the abdomen. The GeiKo point was stimulated at 45 Hz, 5 msec, until the nose twitched in frequency with the stimulator. Analgesia occurred on both sides of the mouth from stimulation of GeiKo on one side but was better on the side opposite to the needle.
In the experiments with LI04, they did extensive trials to examine various frequencies (0.5, 1,10,30,45,100,150,300,500,1000 Hz). They found that some analgesia occurred at all frequencies from 0.5 to 500 Hz but the best analgesia was given by frequencies between 30 and 150 Hz. 1000 Hz was unsatisfactory. Induction was about 15 minutes. They also tested stimulation patterns using pulse durations between 0.1-5.0 msec. The pulse duration had little effect on efficiency of analgesia.
Mice:
EAA at LI04, square wave, 4 Hz, 0.1 msec, for 20 minutes. Output level was adjusted until muscular contraction occurred and was increased to just below the level which caused the mice to vocalise (squeak). Under experimental conditions this had analgesic effects on the nose. The effects were reversed by opiate antagonists (levo-naloxone, naltrexone, cyclazine, diprenorphine) but not by dextro-naloxone (which has little opiate- antagonist effect) (Cheng & Pomeranz 1980).
Dogs, cats, monkeys, cavies and rats:
Lynd in the San Antonio Medical School, Texas, experimented with a "standard surgical incision and suturing" applied to the upper lateral abdomen. A lateral incision through skin and muscle layers was used in all animals. He used only simple insertion of needles (no ES) in the following points GB01; TH23; HT05; BL23,22; KI06. All points were needled bilaterally and the needles were left in position. When the animal lost its reaction to pinprick etc, the incision was made and was then sutured. He reported excellent analgesia but gave no statistics.
4. ADVANTAGES AND DISADVANTAGES OF AA
ADVANTAGES OF AA
AA is a simple, cheap and effective preparation for surgery, especially if combined with tranquilliser or drug anaesthesia. It may be the only method of surgical analgesia which might be available in wartime, national disasters and other emergency situations.
Combination anaesthesia: In humans, a combination of EAA and tranquilliser or anaesthetic drugs is used in thoracic or abdominal surgery, especially in allergic or high-risk patients (circulation, heart, lung, kidney or liver disease). Results were compared with control patients operated under drug anaesthesia alone. They confirmed that the amounts of narcotic and barbiturate drugs needed to maintain adequate anaesthesia were reduced. The EAA-drug group had less deviations from the baseline in heart rate, BP, EEG and body heat loss than the controls during surgery. Blood levels of ACTH, cortisol and aldosterone during surgery did not differ between groups. Recovery of consciousness in the EA-drug group was associated with more alpha- and less beta- activity in the EEG and with less time-space-disorientation on waking up than in the control group. The AP-drug anaesthesia was associated with minimal depression of vital functions and maintained good adaptive reactions (Ponomarenko 1987). EAA combined with diazepam was successful in surgery for fracture of the femoral head in elderly high-risk patients (Glennie-Smith 1986).
Some vet acupuncturists combine EAA with drug analgesia. The dogs are given a tranquillizer (i/v) and small doses of general anaesthetic (much smaller than would be successful without EAA), together with EAA. The results are very good and post-operative recovery is faster and less troublesome than after surgery under conventional anaesthesia.
a. Per-operative benefits: AA can be used in high-risk patients, who might NOT tolerate general or local anaesthesia. These cases include shock (post trauma, haemorrhage), severe debilitation (after chronic disease, malnut-rition or cruelty), toxaemia (renal, hepatic, pulmonary or cardiac cases, toxic pyometra etc); obstetric surgery (Caesarean section etc). It can also be used on very young and very old animals, and in operations lasting up to 10 hours. The effect of AA on the autonomic nervous system prevents shock during the operation so that deaths during or immediately after operation under AA are extremely rare. Operative haemorrhage is also decreased.
b. Post-operative benefits: Because consciousness and reflexes (other than pain response) are retained under EAA, the animal can walk unaided to the recovery area immediately after surgery. There is no risk of self-injury due to ataxia, struggling or falling, as may occur under general anaesthesia or spinal block.
Many authors, operating on animals as well as human patients, report far fewer post-operative complications after AA (less ileus, less urine retention, faster return to normal appetite, less nausea etc). Defecation and urination occur very quickly after EAA and the animal will eat and drink immediately after operation (if it is hungry or thirsty). It is common practice to offer cattle some hay or concentrates during operations and many dogs will placidly accept bits of meat during major surgery.
Post-operative pain and discomfort are almost totally absent. If they occur, AP at the AA sites or at other points for the pain site can control the pain quickly. It is well known that AA effects last for up to 20- 60 minutes after stimulation is ended. An extraordinary finding in monkeys is that peaks of powerful analgesia (interspersed with periods of normal pain sensitivity) can continue for up to 70 hours afterwards (Vierck). This finding demands further research.
After AA, surgical incisions heal much faster, with less oedema, less wound infection and less wound breakdown.
DISADVANTAGES OF AA
a. Analgesia is inadequate in some patients. In animals, expert technique can obtain a success rate of 90-100% between different operators but the success rate has 3 categories:
Excellent results are defined as no indications of pain at any stage in the operation (struggling and vocalising because of physical discomfort, restraint, fear etc must be distinguished from pain reaction). The operation proceeds smoothly at all stages and no other anaesthetic method is required. Slight muscle tremor or local guarding may occur.
Good is defined as short intervals of restlessness or mild struggling during traction of internal organs, suturing of sensitive structures etc. Local muscle tremor or guarding is noted at intervals but the operation can proceed without other anaesthetics.
Fair some pain reactions are noted at intervals during the operation and frequent, intermittent struggling may arise. Marked local tremor and guarding may arise. The operation can still proceed. Some of the effects can be relieved by increasing the frequency or voltage or by relocating the needles.
Failure is defined as pain reactions (fierce struggling, vocalisation, muscle tremor, strong reaction and impossible to proceed with the operation without some other form of anaesthesia.
Skilled operators may have excellent, good and fair rates of about 78, 19 and 3% respectively, with failure rates of zero. However, these success rates are seldom obtained by Western operators in the first year or two of their use of the technique, and many western operators, despite much experience in general AP therapy have not had such good success with AA.
Failure: Western vets can expect a failure rate of 20-50% in the beginning. This is due mainly to incorrect choice of points, incorrect location of points, incorrect needle depth, direction, incorrect or inadequate methods of stimulation, animal factors and surgical technique.
b. Animal factors which may reduce the success rate:
Regional variation in EAA: Certain body regions are more difficult to render insensitive to pain than other regions. Vets who specialise in limb surgery might not get success rates as high as those who specialise in intestinal surgery. Success rates for surgery on the frontal sinus, oesophagus, intestine or bladder may be less than for other body regions. Sex and breed effects may interfere: female cattle respond slightly better than male cattle and domestic cattle may respond better than buffaloes. Species differences: among farm animals cattle and sheep are the best reactors, followed by pigs and horses. Dogs are very good reactors but cats are difficult subjects to handle and their intolerance of morphine may be related to their poor response to AA. Temperament differences: nervous, excitable animals may be good responders to AA but are easily frightened by noise, smell, sight stimuli and may be hard to restrain, despite good analgesia. Dull, depressed animals may appear to be easy to handle but their reaction to AA may be sluggish and not of a high degree. Recumbency: Large animals in the recumbent position need a more expert AA technique than those which are standing. Voltage should be increased in recumbency. External and other stimuli: Animals with an elevated pain threshold under AA can still react to disturbance by environmental stimuli (smell of blood, noise, excitement, fearful sights, proprioceptive stimuli/physical discomfort, clumsy surgical technique etc). These may lower pain threshold and reduce the success rate.
c. Muscle relaxation may be inadequate if the EAA technique is not expert. This may cause ballooning of intestines through abdominal incisions.
d. Induction time (10-40 minutes) may be inconvenient for some surgeons, who may also complain about "electric wires all over the place".
e. Needle dislodgement: Occasionally one or more needles become dislodged, especially if they had not been taped or sutured securely in position. Dislodgement may occur (despite good restraint of the animal) due to strong muscle twitch induced by EAA. If needles fall out, they must be replaced or the analgesia may be poor or absent. When reconnecting a replaced needle, the output voltage should be set to zero and then restored gradually after reconnection.
f. Restraint must be good: This usually needs the presence of at least one assistant at all times after the start of induction. Restraint of small animals, by tying them in dorsal or dorso-lateral recumbency, may cause them some discomfort. Struggling against discomfort needs to be distinguished from possible pain reactions to the surgery. The special EAA harnesses tend to reduce this problem in small animals.
g. EAA demands skilled surgery. Surgical technique must be deft, light, fast and unhesitating. Prolonged probing or manipulation of organs and slow uncertain incision reduce the success rate. Traction on mesentery or ligaments should be kept to a minimum, as should handling of organs and viscera. Although AA has anti-shock effects, heavy traction during EAA can cause autonomic (vagal) reflexes (nausea, vomiting, shock, collapse etc). Where possible, use the hands, rather than surgical retractors, clamps, forceps, probes etc. The hands usually are more sensitive than instruments and are less likely to cause unnecessary trauma/stimulation during surgery.
5. MECHANISMS OF AA
EAA is not hypnosis: In humans, hypnosis or self-hypnosis (deep relaxation) can induce surgical analgesia in sensitive subjects and can be used to treat certain disorders associated with stress. "Animal hypnosis" (the Still Reaction) is not fully analogous to human hypnosis. It is a reversible and involuntary "Tonic Immobility" (TI), induced in many species as a defensive reaction to sudden fright or pain. TI is disrupted easily by noise, movement or touch. In TI, animals may tolerate mildly painful stimuli (pinprick, sound, electric shock) without somatic (muscular) reaction. This is due to descending motor inhibition, not sensory inhibition. They feel the stimulus (as assessed by neuronal discharges in the cerebral cortex) but do not appear to react. There are marked differences between the physiological effects and mechanisms of human and animal hypnosis and those of EAA. Appendix 1 compares and contrasts TI and AA.
Sensory inhibition in EAA: Modern theories attribute the effects of EAA to inhibition of the ascending (sensory) pain signals at three levels: peripheral, spinal and central. Some recent research findings which support this theory are as follows:
1. Many of the most active AA points are directly over, or very close to, main nerve trunks and branches of peripheral nerves.
2. Interruption of the sensory nerve supply proximal to the AA needle site abolishes the EAA effect. This has been demonstrated in many species (including humans) by local anaesthesia (procaine infiltration etc) of the AA point, by nerve block above the point and by spinal block above the entry point of the nerve into the spinal cord. In animals, direct EAA of the isolated nerve gives the same analgesic effect as EAA of the AP point. If the nerve is transected, stimulation of the proximal cut end produces AA but stimulation of the distal cut end produces no effect.
3. In monkeys, cats, rabbits, rats and other laboratory animals, pain stimuli applied at distant regions (for example, the hind limbs) evoke electrical activity in cortical and thalamic neurons. This activity can be monitored by electrodes placed directly into specific neuronal centres of the brain or by surface electrodes at specific regions of the head. EAA at points which cause analgesia of the pain zone suppress or abolish completely the evoked potentials in the brain. (There is also experimental evidence that transmission of pain signals is inhibited by AA at peripheral and spinal levels.
4. Experimental electrolytic lesions placed around the 3rd ventricle (midbrain) or surgical hypophysectomy completely abolish AA effects. The midbrain and hypothalamic areas are rich in opiate receptors. (Certain strains of mice, which have no opiate receptors because of a genetic abnormality can not respond to AA). Levo-naloxone, naltrexone and other opiate antagonists prevent and abolish much of the analgesic effect of AP in humans and animals.
Thus far, these facts indicate that the signals generated by needling or
ES of the AA points are transmitted via the peripheral sensory nerves to the spinal cord and that they activate a descending brain-based pain-inhibition mechanism, especially the midbrain and hypothalamus. There are also "pain inhibition gates" in the spinal cord. Thus, the "ascending pain signals" are blocked at spinal and midbrain level and fail to reach the cerebral cortex.
There is very strong evidence that the pain inhibition mechanism involves activation of opiate and serotonin (5HT) receptors in the brain and, probably, other sites also. This evidence is strengthened by the following observations:
AA stimulation causes release of endorphins, enkephalins (endogenous morphine compounds) and ACTH. This has been confirmed by chemical analysis of tissues.
AP stimulation of certain points (especially Earpoint "Lung"; LI04; ST36; GB34 etc) relieves the symptoms of narcotic and alcohol withdrawal within 10-30 minutes in human addicts and in laboratory animals addicted experimentally to morphine or heroin. These points have major AA effects (Patterson).
Stimulation of AA points on one side of the body may have analgesic effects on the opposite side. In most species of animal, the stronger analgesia is usually on the same side as the needles. However, Toda et al found a stronger effect on the opposite side when the GeiKo point was used in rodents.
Although ES of single points such as ST06; LI04; TH08 etc may cause analgesia over a wide area, there is some specificity between the anatomical location of the point and the area of analgesia. For instance point PC06 or TH08 will give better analgesia of the arm and thorax than of the leg, whereas SP06 or ST36 will give better analgesia of the leg and abdomen than of the arm. Also, needling of "false points" usually fails to produce AA, even though the false points can be quite near the correct points.
A certain degree of side-to-side and region-to-region specificity exists between the AA point and "target zone of analgesia". This suggests that the AA signals are going to specific sites in the brain. It is known already that the brain contains 3-dimensional projection areas (both sensory and motor) for all body regions. It appears that endorphin release in these specific areas is the main mechanism of AA.
Many years before the endorphins were discovered, the Chinese had evidence
that a morphine-like analgesic factor was released into the blood and cerebro-spinal fluid by AA (Niboyet et al). Cross-perfusion studies were conducted in rats, dogs, rabbits and monkeys in China. AA or EAA was established in experimental animals and cerebro-spinal fluid, whole blood or serum was perfused directly or indirectly into animals (of the same species) which had received no AP. Analgesia developed in the recipients but was not as marked as in the donor animals. An extraordinary finding was that if the donor had a localised analgesia (specific to one side or one region), the recipient also developed analgesia on the same side and in the same region as the donor. This suggests that humoral factors are released by EAA and that they activate specific receptors (now known to be opiate receptors) in specific regions of the brain and spinal cord of both donor and recipient animal. Many neurophysiologists find it difficult to accept that such specificity can exist. In the past few years, Chinese and Western workers have confirmed that release of endorphin is involved in AA.
As well as releasing endorphins, EAA also releases ACTH, which increases the cortisol levels in blood. This was proved in horses by Cheng et al (1980). In these experiments, EAA was given at 4-5 points to above the threshold of muscle twitching; biphasic pulses, 5 Hz, .25 msec duration for 30 minutes. The points were chosen from points effective in treating limb pain in horses, BL13,65; GB26; PC09; KI01,02. The needles were 10 cm long and were inserted to a depth of 3-5 cm. Cortisol levels before and after AP were measured. A control group of horses received "false" AP, by the same method but at non-points 5 cm below GB30,39; BL13,18,47 and the needles were inserted subcutaneously only (not to the deeper levels as in the active points). EAA increased cortisol by 40% above pretrial values but "false EAA" had little effect. (Note: If "false points" above or below the "real points" are used, some hypoalgesia may occur because the same nerve trunk may be stimulated. If the "false points" are lateral or medial to the "real points" (i.e. not over the nerve trunk), needling the "false points" is usually not effective). The difference between real and false EAA was highly significant. Recent research has also shows that serotonin (5HT) is involved in EAA and that oral administration of 5HT precursors, such as d-phenyl alanine, greatly enhances AA and can turn "non-responders" into "responders".
Frost reported 3 cases of human AA following needling of points below a traumatic transection of the spinal cord in the region cervical vertebrae 1-6. Analgesia occurred above the transection.
Terral repeated the Chinese cross-perfusion EAA studies in rabbits. He confirmed that EAA released a humoral analgesic factor in rabbits even when the spinal cord was severed behind the medulla oblongata.
The mechanisms of AA can be summarised as follows: Signals caused by stimulation of AA points are carried in the peripheral sensory nerves to the spinal cord. At this level they may activate local (spinal) pain inhibition gates. Spinal signals are also transmitted to specific sites in the thalamus, hypothalamus and midbrain, via the ascending tracts (spino-thalamic tracts, ventro-lateral funiculi). These signals stimulate the local (and systemic) release of endorphin, serotonin (5HT) and other neurotransmitters not discussed in this paper. The endorphin activates the opiate receptors, which "switch on" the pain inhibition mechanism specific for those areas related to the needle site and its projections at brain level. Simultaneous ACTH release from hypothalamic areas induces cortisol secretion by the adrenal, thus preparing the animal to withstand the surgical stress and to assist (anti-inflammatory effect) in wound healing.
Release of ACTH by EAA could be important in treating allergies, arthritis, inflammation and shock. Some AA signals can reach the pain inhibition centres by routes outside of the spinal cord, possibly by (a) cell-to-cell transmission through the skin and soft tissues (as in a bee-colony); (b) by the autonomic nervous system and (c) by release of some (yet unknown) substances from the needle-site into the bloodstream.
6. OTHER METHODS OF STIMULATION-PRODUCED ANALGESIA (SPA)
SPA originally referred to analgesia produced by direct stimulation of specific brain sites, especially the area around the 3rd ventricle, the periaquaductal grey matter (PAG). In humans and animals, this produces powerful analgesia over the whole body. It has many parallels with EAA. SPA is abolished by opiate antagonists (naloxone etc). It involves endorphin release but over a wider area of the brain than EAA. This probably explains the more localised analgesia of EAA. Direct stimulation of the thalamus or dorsal spinal cord roots also produces potent analgesia and ES of permanently implanted electrodes in these sites has been used in treating severe intractable pain in humans.
Long-term direct stimulation of brain or cord sites involves some risks (possible electrolytic lesions in brain/nerve tissue, risk of infection etc). Because direct methods were effective but risky, researchers began to examine the possibility of indirect stimulation of the nervous tissue, via peripheral nerves. This led to the development of various forms of transcutaneous ES analgesia (TESA), transcutaneous nerve stimulation (TNS), transcutaneous electro-neural stimulation (TENS) etc. These methods are widely used internationally in physiotherapy and for personal use by outpatients of pain clinics. Workers familiar with the AP system found that TESA, TENS etc were more effective if the electrodes were applied to the affected local areas plus (AP points, Trigger Points, organ reflex points etc). TESA mechanisms are not fully researched yet but there is strong evidence that they are similar to those of EAA.
Under experimental conditions, surgical intervention has been done in animals under SPA but the main use of SPA and TESA has been in the control of clinical pain.
Other types of SPA include vaginal stimulation analgesia, electro-restraint electro-anaesthesia/electro-narcosis and electro-sleep.
Vaginal Stimulation Analgesia (VSA): Mechanical (glass probe) or electrical stimulation of the vagina in rats produces a powerful analgesia over the whole body but the mechanism does not involve the opiate receptors in the brain because opiate antagonists (naloxone etc) do not interfere with the analgesia. Thus, VSA is mediated by mechanisms different from SPA, TESA and EAA.
Electro-restraint: Reports from Poland claimed that positive clamp electrodes fastened to the ear and a negative tongs electrode fastened to the nose gives excellent restraint in cows. Using this technique in 58 cows, the author (Szczerbac) was able to pare the hooves with no difficulty and no defence reaction from the cows. The frequency of stimulation was 160-200 Hz and the current was 4-16 mA. Details of induction time are not available in the English summary of the article but I believe that induction was probably very short. The Ear roots and the nose (especially GV25 and 26) are used as EAA points in some Chinese prescriptions for humans and animals. However, I suspect that the Polish instrument is used as a method of restraint rather than a true analgesia. It is also interesting that stimulation of the nasal area (the simple tongs or fingers in cattle; the rope "twitch" in horses) and of the ear-root (in both cattle and horses) has been used internationally for many centuries as a method of restraint in large animals. Since the Polish report, a similar instrument has been available commercially in Australia and the USA. Its tradename is STOCKSTILL. It applies a strong electrical stimulus to the cheek/mouth/nose and the base of the tail or other area, as required, i.e. opposite ends of the spinal cord. To knock the animal, current is applied to the cheek and lumbar area. The animal falls to the ground immediately and simple surgery can be done with great ease. However, the British Veterinary Association has not accepted that this technique is humane and painless. It seems that this method of electro-restraint has little analgesic power but rather that it acts by a type of spinal shock which induces spastic paralysis of the motor nerves from the spinal cord. More research is required on this method but it appears to have little or no similarity in its effects or mechanisms of action to EAA or SPA.
Electro-narcosis and electro-anaesthesia are terms used for another type of electrically induced anaesthesia which uses indirect electrical stimulation of the thalamus to produce unconsciousness and total anaesthesia. The induction period in humans and animals is very short, usually 1-5 minutes. Unconsciousness and anaesthesia can be maintained for long periods while stimulation continues. Consciousness returns immediately stimulation ceases. In early trials, needle electrodes were used in various sites on the head: temples, vertex, occipital area, mastoid area, forehead etc. Contact electrodes, such as sponges soaked in saline or metal disc electrodes were used later. Kano et al have done many experiments with the method in monkeys. They found that needle electrodes could produce third degree burns, stretching between the electrodes but that contact electrodes did not produce tissue damage. Their suggestion for best results was to use high frequency current passed between B-C and B1-D, where electrodes B and B1 are over the greater occipital nerves and C and D are over the greater auricular nerves.
They proved that the stimuli are transmitted to the brain by these nerves by a local ring-block around the scalp, using 0.25% lidocaine. The local anaesthetic blocked the phenomenon.
Anaesthesia produced by these techniques is sufficient for major surgery in man and animals. In her book on AP in the treatment of drug addicts, Margaret Patterson traces the history of these techniques. Electro-anaesthesia has a long history in western medicine dating back to 1902 (long before the development of EAA, SPA, TESA etc). It was discovered by Francois Luduc in 1902. The first human operations using the method were in 1972 in the Necker Hospital, Paris. Since then, more than 400 operations (including arterial grafting, kidney transplants, urological and intestinal surgery) have been done using that method in the hospital. Other hospitals in France are also using the method. The electrode placement is: 2 electrodes (anodes) behind the mastoids (one each) and one cathode between the eyebrows; unidirectional high frequency current (See Patterson for details). Post-operative analgesia is marked, lasting 6-48 hours, as in EAA. Post-operative infection, abscesses etc are rare (3%) as compared with operations under general anaesthesia (17% abscesses) in the same hospital. This also parallels the EAA effect but loss of consciousness during electro-anaesthesia indicates that the mechanisms differ from those in EAA.
Electro-Sleep or Cerebral Electro-therapy (CET) has some parallels with electroanaesthesia but it differs in other respects. It is used in therapy of various diseases with underlying disturbances of cortical regulation of somatic function and in all disorders with psycho-autonomic manifestations. It was widely used in the old USSR and in Austria but there is no agreement on the mechanism of the effects or on the stimulation parameters used to induce electrosleep. One Russian worker (Sergeer - see Patterson for other details) used rectangular pulse, constant polarity, pulse duration 0.2-0.3 msec, current intensity 15-20 mA, 80-100 Hz, for 30-120 minutes per day. A course of treatment lasted 20-25 sessions.
ADVANTAGES OF AA
AA is a simple, cheap and effective preparation for surgery, especially if combined with tranquilliser or drug anaesthesia. It may be the only method of surgical analgesia which might be available in wartime, national disasters and other emergency situations.
Combination anaesthesia: In humans, a combination of EAA and tranquilliser or anaesthetic drugs is used in thoracic or abdominal surgery, especially in allergic or high-risk patients (circulation, heart, lung, kidney or liver disease). Results were compared with control patients operated under drug anaesthesia alone. They confirmed that the amounts of narcotic and barbiturate drugs needed to maintain adequate anaesthesia were reduced. The EAA-drug group had less deviations from the baseline in heart rate, BP, EEG and body heat loss than the controls during surgery. Blood levels of ACTH, cortisol and aldosterone during surgery did not differ between groups. Recovery of consciousness in the EA-drug group was associated with more alpha- and less beta- activity in the EEG and with less time-space-disorientation on waking up than in the control group. The AP-drug anaesthesia was associated with minimal depression of vital functions and maintained good adaptive reactions (Ponomarenko 1987). EAA combined with diazepam was successful in surgery for fracture of the femoral head in elderly high-risk patients (Glennie-Smith 1986).
Some vet acupuncturists combine EAA with drug analgesia. The dogs are given a tranquillizer (i/v) and small doses of general anaesthetic (much smaller than would be successful without EAA), together with EAA. The results are very good and post-operative recovery is faster and less troublesome than after surgery under conventional anaesthesia.
a. Per-operative benefits: AA can be used in high-risk patients, who might NOT tolerate general or local anaesthesia. These cases include shock (post trauma, haemorrhage), severe debilitation (after chronic disease, malnut-rition or cruelty), toxaemia (renal, hepatic, pulmonary or cardiac cases, toxic pyometra etc); obstetric surgery (Caesarean section etc). It can also be used on very young and very old animals, and in operations lasting up to 10 hours. The effect of AA on the autonomic nervous system prevents shock during the operation so that deaths during or immediately after operation under AA are extremely rare. Operative haemorrhage is also decreased.
b. Post-operative benefits: Because consciousness and reflexes (other than pain response) are retained under EAA, the animal can walk unaided to the recovery area immediately after surgery. There is no risk of self-injury due to ataxia, struggling or falling, as may occur under general anaesthesia or spinal block.
Many authors, operating on animals as well as human patients, report far fewer post-operative complications after AA (less ileus, less urine retention, faster return to normal appetite, less nausea etc). Defecation and urination occur very quickly after EAA and the animal will eat and drink immediately after operation (if it is hungry or thirsty). It is common practice to offer cattle some hay or concentrates during operations and many dogs will placidly accept bits of meat during major surgery.
Post-operative pain and discomfort are almost totally absent. If they occur, AP at the AA sites or at other points for the pain site can control the pain quickly. It is well known that AA effects last for up to 20- 60 minutes after stimulation is ended. An extraordinary finding in monkeys is that peaks of powerful analgesia (interspersed with periods of normal pain sensitivity) can continue for up to 70 hours afterwards (Vierck). This finding demands further research.
After AA, surgical incisions heal much faster, with less oedema, less wound infection and less wound breakdown.
DISADVANTAGES OF AA
a. Analgesia is inadequate in some patients. In animals, expert technique can obtain a success rate of 90-100% between different operators but the success rate has 3 categories:
Excellent results are defined as no indications of pain at any stage in the operation (struggling and vocalising because of physical discomfort, restraint, fear etc must be distinguished from pain reaction). The operation proceeds smoothly at all stages and no other anaesthetic method is required. Slight muscle tremor or local guarding may occur.
Good is defined as short intervals of restlessness or mild struggling during traction of internal organs, suturing of sensitive structures etc. Local muscle tremor or guarding is noted at intervals but the operation can proceed without other anaesthetics.
Fair some pain reactions are noted at intervals during the operation and frequent, intermittent struggling may arise. Marked local tremor and guarding may arise. The operation can still proceed. Some of the effects can be relieved by increasing the frequency or voltage or by relocating the needles.
Failure is defined as pain reactions (fierce struggling, vocalisation, muscle tremor, strong reaction and impossible to proceed with the operation without some other form of anaesthesia.
Skilled operators may have excellent, good and fair rates of about 78, 19 and 3% respectively, with failure rates of zero. However, these success rates are seldom obtained by Western operators in the first year or two of their use of the technique, and many western operators, despite much experience in general AP therapy have not had such good success with AA.
Failure: Western vets can expect a failure rate of 20-50% in the beginning. This is due mainly to incorrect choice of points, incorrect location of points, incorrect needle depth, direction, incorrect or inadequate methods of stimulation, animal factors and surgical technique.
b. Animal factors which may reduce the success rate:
Regional variation in EAA: Certain body regions are more difficult to render insensitive to pain than other regions. Vets who specialise in limb surgery might not get success rates as high as those who specialise in intestinal surgery. Success rates for surgery on the frontal sinus, oesophagus, intestine or bladder may be less than for other body regions. Sex and breed effects may interfere: female cattle respond slightly better than male cattle and domestic cattle may respond better than buffaloes. Species differences: among farm animals cattle and sheep are the best reactors, followed by pigs and horses. Dogs are very good reactors but cats are difficult subjects to handle and their intolerance of morphine may be related to their poor response to AA. Temperament differences: nervous, excitable animals may be good responders to AA but are easily frightened by noise, smell, sight stimuli and may be hard to restrain, despite good analgesia. Dull, depressed animals may appear to be easy to handle but their reaction to AA may be sluggish and not of a high degree. Recumbency: Large animals in the recumbent position need a more expert AA technique than those which are standing. Voltage should be increased in recumbency. External and other stimuli: Animals with an elevated pain threshold under AA can still react to disturbance by environmental stimuli (smell of blood, noise, excitement, fearful sights, proprioceptive stimuli/physical discomfort, clumsy surgical technique etc). These may lower pain threshold and reduce the success rate.
c. Muscle relaxation may be inadequate if the EAA technique is not expert. This may cause ballooning of intestines through abdominal incisions.
d. Induction time (10-40 minutes) may be inconvenient for some surgeons, who may also complain about "electric wires all over the place".
e. Needle dislodgement: Occasionally one or more needles become dislodged, especially if they had not been taped or sutured securely in position. Dislodgement may occur (despite good restraint of the animal) due to strong muscle twitch induced by EAA. If needles fall out, they must be replaced or the analgesia may be poor or absent. When reconnecting a replaced needle, the output voltage should be set to zero and then restored gradually after reconnection.
f. Restraint must be good: This usually needs the presence of at least one assistant at all times after the start of induction. Restraint of small animals, by tying them in dorsal or dorso-lateral recumbency, may cause them some discomfort. Struggling against discomfort needs to be distinguished from possible pain reactions to the surgery. The special EAA harnesses tend to reduce this problem in small animals.
g. EAA demands skilled surgery. Surgical technique must be deft, light, fast and unhesitating. Prolonged probing or manipulation of organs and slow uncertain incision reduce the success rate. Traction on mesentery or ligaments should be kept to a minimum, as should handling of organs and viscera. Although AA has anti-shock effects, heavy traction during EAA can cause autonomic (vagal) reflexes (nausea, vomiting, shock, collapse etc). Where possible, use the hands, rather than surgical retractors, clamps, forceps, probes etc. The hands usually are more sensitive than instruments and are less likely to cause unnecessary trauma/stimulation during surgery.
5. MECHANISMS OF AA
EAA is not hypnosis: In humans, hypnosis or self-hypnosis (deep relaxation) can induce surgical analgesia in sensitive subjects and can be used to treat certain disorders associated with stress. "Animal hypnosis" (the Still Reaction) is not fully analogous to human hypnosis. It is a reversible and involuntary "Tonic Immobility" (TI), induced in many species as a defensive reaction to sudden fright or pain. TI is disrupted easily by noise, movement or touch. In TI, animals may tolerate mildly painful stimuli (pinprick, sound, electric shock) without somatic (muscular) reaction. This is due to descending motor inhibition, not sensory inhibition. They feel the stimulus (as assessed by neuronal discharges in the cerebral cortex) but do not appear to react. There are marked differences between the physiological effects and mechanisms of human and animal hypnosis and those of EAA. Appendix 1 compares and contrasts TI and AA.
Sensory inhibition in EAA: Modern theories attribute the effects of EAA to inhibition of the ascending (sensory) pain signals at three levels: peripheral, spinal and central. Some recent research findings which support this theory are as follows:
1. Many of the most active AA points are directly over, or very close to, main nerve trunks and branches of peripheral nerves.
2. Interruption of the sensory nerve supply proximal to the AA needle site abolishes the EAA effect. This has been demonstrated in many species (including humans) by local anaesthesia (procaine infiltration etc) of the AA point, by nerve block above the point and by spinal block above the entry point of the nerve into the spinal cord. In animals, direct EAA of the isolated nerve gives the same analgesic effect as EAA of the AP point. If the nerve is transected, stimulation of the proximal cut end produces AA but stimulation of the distal cut end produces no effect.
3. In monkeys, cats, rabbits, rats and other laboratory animals, pain stimuli applied at distant regions (for example, the hind limbs) evoke electrical activity in cortical and thalamic neurons. This activity can be monitored by electrodes placed directly into specific neuronal centres of the brain or by surface electrodes at specific regions of the head. EAA at points which cause analgesia of the pain zone suppress or abolish completely the evoked potentials in the brain. (There is also experimental evidence that transmission of pain signals is inhibited by AA at peripheral and spinal levels.
4. Experimental electrolytic lesions placed around the 3rd ventricle (midbrain) or surgical hypophysectomy completely abolish AA effects. The midbrain and hypothalamic areas are rich in opiate receptors. (Certain strains of mice, which have no opiate receptors because of a genetic abnormality can not respond to AA). Levo-naloxone, naltrexone and other opiate antagonists prevent and abolish much of the analgesic effect of AP in humans and animals.
Thus far, these facts indicate that the signals generated by needling or
ES of the AA points are transmitted via the peripheral sensory nerves to the spinal cord and that they activate a descending brain-based pain-inhibition mechanism, especially the midbrain and hypothalamus. There are also "pain inhibition gates" in the spinal cord. Thus, the "ascending pain signals" are blocked at spinal and midbrain level and fail to reach the cerebral cortex.
There is very strong evidence that the pain inhibition mechanism involves activation of opiate and serotonin (5HT) receptors in the brain and, probably, other sites also. This evidence is strengthened by the following observations:
AA stimulation causes release of endorphins, enkephalins (endogenous morphine compounds) and ACTH. This has been confirmed by chemical analysis of tissues.
AP stimulation of certain points (especially Earpoint "Lung"; LI04; ST36; GB34 etc) relieves the symptoms of narcotic and alcohol withdrawal within 10-30 minutes in human addicts and in laboratory animals addicted experimentally to morphine or heroin. These points have major AA effects (Patterson).
Stimulation of AA points on one side of the body may have analgesic effects on the opposite side. In most species of animal, the stronger analgesia is usually on the same side as the needles. However, Toda et al found a stronger effect on the opposite side when the GeiKo point was used in rodents.
Although ES of single points such as ST06; LI04; TH08 etc may cause analgesia over a wide area, there is some specificity between the anatomical location of the point and the area of analgesia. For instance point PC06 or TH08 will give better analgesia of the arm and thorax than of the leg, whereas SP06 or ST36 will give better analgesia of the leg and abdomen than of the arm. Also, needling of "false points" usually fails to produce AA, even though the false points can be quite near the correct points.
A certain degree of side-to-side and region-to-region specificity exists between the AA point and "target zone of analgesia". This suggests that the AA signals are going to specific sites in the brain. It is known already that the brain contains 3-dimensional projection areas (both sensory and motor) for all body regions. It appears that endorphin release in these specific areas is the main mechanism of AA.
Many years before the endorphins were discovered, the Chinese had evidence
that a morphine-like analgesic factor was released into the blood and cerebro-spinal fluid by AA (Niboyet et al). Cross-perfusion studies were conducted in rats, dogs, rabbits and monkeys in China. AA or EAA was established in experimental animals and cerebro-spinal fluid, whole blood or serum was perfused directly or indirectly into animals (of the same species) which had received no AP. Analgesia developed in the recipients but was not as marked as in the donor animals. An extraordinary finding was that if the donor had a localised analgesia (specific to one side or one region), the recipient also developed analgesia on the same side and in the same region as the donor. This suggests that humoral factors are released by EAA and that they activate specific receptors (now known to be opiate receptors) in specific regions of the brain and spinal cord of both donor and recipient animal. Many neurophysiologists find it difficult to accept that such specificity can exist. In the past few years, Chinese and Western workers have confirmed that release of endorphin is involved in AA.
As well as releasing endorphins, EAA also releases ACTH, which increases the cortisol levels in blood. This was proved in horses by Cheng et al (1980). In these experiments, EAA was given at 4-5 points to above the threshold of muscle twitching; biphasic pulses, 5 Hz, .25 msec duration for 30 minutes. The points were chosen from points effective in treating limb pain in horses, BL13,65; GB26; PC09; KI01,02. The needles were 10 cm long and were inserted to a depth of 3-5 cm. Cortisol levels before and after AP were measured. A control group of horses received "false" AP, by the same method but at non-points 5 cm below GB30,39; BL13,18,47 and the needles were inserted subcutaneously only (not to the deeper levels as in the active points). EAA increased cortisol by 40% above pretrial values but "false EAA" had little effect. (Note: If "false points" above or below the "real points" are used, some hypoalgesia may occur because the same nerve trunk may be stimulated. If the "false points" are lateral or medial to the "real points" (i.e. not over the nerve trunk), needling the "false points" is usually not effective). The difference between real and false EAA was highly significant. Recent research has also shows that serotonin (5HT) is involved in EAA and that oral administration of 5HT precursors, such as d-phenyl alanine, greatly enhances AA and can turn "non-responders" into "responders".
Frost reported 3 cases of human AA following needling of points below a traumatic transection of the spinal cord in the region cervical vertebrae 1-6. Analgesia occurred above the transection.
Terral repeated the Chinese cross-perfusion EAA studies in rabbits. He confirmed that EAA released a humoral analgesic factor in rabbits even when the spinal cord was severed behind the medulla oblongata.
The mechanisms of AA can be summarised as follows: Signals caused by stimulation of AA points are carried in the peripheral sensory nerves to the spinal cord. At this level they may activate local (spinal) pain inhibition gates. Spinal signals are also transmitted to specific sites in the thalamus, hypothalamus and midbrain, via the ascending tracts (spino-thalamic tracts, ventro-lateral funiculi). These signals stimulate the local (and systemic) release of endorphin, serotonin (5HT) and other neurotransmitters not discussed in this paper. The endorphin activates the opiate receptors, which "switch on" the pain inhibition mechanism specific for those areas related to the needle site and its projections at brain level. Simultaneous ACTH release from hypothalamic areas induces cortisol secretion by the adrenal, thus preparing the animal to withstand the surgical stress and to assist (anti-inflammatory effect) in wound healing.
Release of ACTH by EAA could be important in treating allergies, arthritis, inflammation and shock. Some AA signals can reach the pain inhibition centres by routes outside of the spinal cord, possibly by (a) cell-to-cell transmission through the skin and soft tissues (as in a bee-colony); (b) by the autonomic nervous system and (c) by release of some (yet unknown) substances from the needle-site into the bloodstream.
6. OTHER METHODS OF STIMULATION-PRODUCED ANALGESIA (SPA)
SPA originally referred to analgesia produced by direct stimulation of specific brain sites, especially the area around the 3rd ventricle, the periaquaductal grey matter (PAG). In humans and animals, this produces powerful analgesia over the whole body. It has many parallels with EAA. SPA is abolished by opiate antagonists (naloxone etc). It involves endorphin release but over a wider area of the brain than EAA. This probably explains the more localised analgesia of EAA. Direct stimulation of the thalamus or dorsal spinal cord roots also produces potent analgesia and ES of permanently implanted electrodes in these sites has been used in treating severe intractable pain in humans.
Long-term direct stimulation of brain or cord sites involves some risks (possible electrolytic lesions in brain/nerve tissue, risk of infection etc). Because direct methods were effective but risky, researchers began to examine the possibility of indirect stimulation of the nervous tissue, via peripheral nerves. This led to the development of various forms of transcutaneous ES analgesia (TESA), transcutaneous nerve stimulation (TNS), transcutaneous electro-neural stimulation (TENS) etc. These methods are widely used internationally in physiotherapy and for personal use by outpatients of pain clinics. Workers familiar with the AP system found that TESA, TENS etc were more effective if the electrodes were applied to the affected local areas plus (AP points, Trigger Points, organ reflex points etc). TESA mechanisms are not fully researched yet but there is strong evidence that they are similar to those of EAA.
Under experimental conditions, surgical intervention has been done in animals under SPA but the main use of SPA and TESA has been in the control of clinical pain.
Other types of SPA include vaginal stimulation analgesia, electro-restraint electro-anaesthesia/electro-narcosis and electro-sleep.
Vaginal Stimulation Analgesia (VSA): Mechanical (glass probe) or electrical stimulation of the vagina in rats produces a powerful analgesia over the whole body but the mechanism does not involve the opiate receptors in the brain because opiate antagonists (naloxone etc) do not interfere with the analgesia. Thus, VSA is mediated by mechanisms different from SPA, TESA and EAA.
Electro-restraint: Reports from Poland claimed that positive clamp electrodes fastened to the ear and a negative tongs electrode fastened to the nose gives excellent restraint in cows. Using this technique in 58 cows, the author (Szczerbac) was able to pare the hooves with no difficulty and no defence reaction from the cows. The frequency of stimulation was 160-200 Hz and the current was 4-16 mA. Details of induction time are not available in the English summary of the article but I believe that induction was probably very short. The Ear roots and the nose (especially GV25 and 26) are used as EAA points in some Chinese prescriptions for humans and animals. However, I suspect that the Polish instrument is used as a method of restraint rather than a true analgesia. It is also interesting that stimulation of the nasal area (the simple tongs or fingers in cattle; the rope "twitch" in horses) and of the ear-root (in both cattle and horses) has been used internationally for many centuries as a method of restraint in large animals. Since the Polish report, a similar instrument has been available commercially in Australia and the USA. Its tradename is STOCKSTILL. It applies a strong electrical stimulus to the cheek/mouth/nose and the base of the tail or other area, as required, i.e. opposite ends of the spinal cord. To knock the animal, current is applied to the cheek and lumbar area. The animal falls to the ground immediately and simple surgery can be done with great ease. However, the British Veterinary Association has not accepted that this technique is humane and painless. It seems that this method of electro-restraint has little analgesic power but rather that it acts by a type of spinal shock which induces spastic paralysis of the motor nerves from the spinal cord. More research is required on this method but it appears to have little or no similarity in its effects or mechanisms of action to EAA or SPA.
Electro-narcosis and electro-anaesthesia are terms used for another type of electrically induced anaesthesia which uses indirect electrical stimulation of the thalamus to produce unconsciousness and total anaesthesia. The induction period in humans and animals is very short, usually 1-5 minutes. Unconsciousness and anaesthesia can be maintained for long periods while stimulation continues. Consciousness returns immediately stimulation ceases. In early trials, needle electrodes were used in various sites on the head: temples, vertex, occipital area, mastoid area, forehead etc. Contact electrodes, such as sponges soaked in saline or metal disc electrodes were used later. Kano et al have done many experiments with the method in monkeys. They found that needle electrodes could produce third degree burns, stretching between the electrodes but that contact electrodes did not produce tissue damage. Their suggestion for best results was to use high frequency current passed between B-C and B1-D, where electrodes B and B1 are over the greater occipital nerves and C and D are over the greater auricular nerves.
They proved that the stimuli are transmitted to the brain by these nerves by a local ring-block around the scalp, using 0.25% lidocaine. The local anaesthetic blocked the phenomenon.
Anaesthesia produced by these techniques is sufficient for major surgery in man and animals. In her book on AP in the treatment of drug addicts, Margaret Patterson traces the history of these techniques. Electro-anaesthesia has a long history in western medicine dating back to 1902 (long before the development of EAA, SPA, TESA etc). It was discovered by Francois Luduc in 1902. The first human operations using the method were in 1972 in the Necker Hospital, Paris. Since then, more than 400 operations (including arterial grafting, kidney transplants, urological and intestinal surgery) have been done using that method in the hospital. Other hospitals in France are also using the method. The electrode placement is: 2 electrodes (anodes) behind the mastoids (one each) and one cathode between the eyebrows; unidirectional high frequency current (See Patterson for details). Post-operative analgesia is marked, lasting 6-48 hours, as in EAA. Post-operative infection, abscesses etc are rare (3%) as compared with operations under general anaesthesia (17% abscesses) in the same hospital. This also parallels the EAA effect but loss of consciousness during electro-anaesthesia indicates that the mechanisms differ from those in EAA.
Electro-Sleep or Cerebral Electro-therapy (CET) has some parallels with electroanaesthesia but it differs in other respects. It is used in therapy of various diseases with underlying disturbances of cortical regulation of somatic function and in all disorders with psycho-autonomic manifestations. It was widely used in the old USSR and in Austria but there is no agreement on the mechanism of the effects or on the stimulation parameters used to induce electrosleep. One Russian worker (Sergeer - see Patterson for other details) used rectangular pulse, constant polarity, pulse duration 0.2-0.3 msec, current intensity 15-20 mA, 80-100 Hz, for 30-120 minutes per day. A course of treatment lasted 20-25 sessions.
ACUPUNCTURE ANALGESIA: FURTHER READING
1 Anon (1975) (Academy of Traditional Medicine). Outline of Chinese AP. Foreign Languages Press, Peking.
1a Anon (1980) Peking, Shanghai, Nanking Colleges of Trad. Chin. Med., with Academy of Traditional Chinese Medicines. Essentials of Chinese AP. Foreign Languages Press, Peking.
2 Anon (1974) The Principles and practice use of AA. Medicine & Health Publishing Co., Hong Kong.
3 Klide,A.M. and Kung,A.H. (1977) Veterinary AP. University of Pennsylvania Press, Philadelphia.
4 Matsumoto,T. (1973) AP of physicians. Charles C. Thomas, Springfield, Illinois.
5 Niboyet,J.E.H. et al. (1973) L'anaesthesia par l'AP. Maisonneuve.
6 Patterson,M.A. (1975) Addictions can be cured. Lion Publishers, Berkhamsted, U.K. and personal communication (1975-1980).
7 Glennie-Smith,K. (1986) Stimulation-produced analgesia for major joint surgery in elderly poor-risk patients: a feasibility study. AJA, 1987, 15, 180, ex paper to the International Medical Acupuncture Conference, London, May 4-6.
8 Ponomarenko,T.P. (1987) Experience of using electro-AP in combined analgesia. SJA&ET, 2, 42-45.
REFERENCES
1 Anon (1977) Akita AP Research Unit, Cattle Health Centre, 6-8 Nakadori, Akita-Shi, Akitaken, Japan. Electrostimulation of the thoraco-lumbar and lumbo-sacral space in surgical analgesia of cattle and pigs. Personal communication.
2 Arambarri,R. et al (1975) EAA in veterinary surgery. Revue Med. Vet. 126, 1231-1236.
3 Cheng,R.S.A. and Pomeranz,B.H. (1980) EAA is mediated by stereospecific opiate receptors and is reversed by antagonists of type 1 receptors. Life Sciences, 26, 631-638.
4 Cheng,R. et al (1980) EAA elevates blood cortisol levels in naive horses; sham treatment has no effect. Intern. J. Neuroscience, 10, 95-97.
5 Frost,E.A.M. and Hsu (1975) Neurophysiological pathways in AP. Amer. J. Acup. 3, 331-.
6 Humphries,V.J. (1977) EAA in abdominal surgery in a horse. Case history from International Veterinary Acupuncture Society (IVAS).
7 Ishizaki,S. et al (1977) EAA in high risk dogs. Jap. J. vet. Anaesth., No.8, 21-28 and World Acupuncture Congress, Paris, Summer, 1978.
8 Jacobs,S. et al (1973) EAA in the squirrel monkey. Proc. 1st International Symposium on Pain, Seattle.
9 Kadono,H et al (1977) EEG during EAA in the dog. Jap. J. Vet. Sci., 39, 539-547.
10 Kano,T et al (1976) Electroanaesthesia (EA) studies:EA produced by stimulation of sensory nerves of the scalp of rhesus monkeys. Anaesthesia and Analgesia, Current Researches, 55, 536-541.
11 Kitazawa,K. et al (1975) Experimental studies on EAA in the dog. Proc. 20th World Vet. Congress, Thessaloniki, 1657-1658 and (1975) Studies on EAA in the dog; confirmation of the effect. Jap. J. vet. Anaesth., No. 6, 7-14.
12 Kothbauer,0. (1973) EAA in teat analgesia in cows. Austrian Med. J., 28, 1037-1039 and EAA in Caesarean section in cows. Personal Communication (1977) and (1975) Wiener Tierarztl. Monatsschr., 62, 394-396.
13 Lambardt,A. (1975) AA versuche bei katzen. Der Prakt. Tierarzt, 1/1975, 33-36.
14 Lynd,F.T. (1975) AP analgesia investigations in animals. Internal report, Department of Laboratory Animal Medicine, Medical School, University of Texas, San Antonio, Texas 78284. 5 pages.
15 Matsumoto,T. et al (1974) AA in animals: selection of optimal electric stimulation. American Surgeon, October, 558-563.
16 O'Boyle,M.A. and Vajda,G.K. (1975) AA £or abdominal surgery. Mod. Vet. Pract., 56, 705-707.
17 Ralston,N.C. and Ralston,B.L. (1978) AA for cystotomy surgery in a dog. Amer. J. Acup., 6, 75-76.
17a Still,J. (1987) AP for laparotomy in dogs and cats: an experimental study: American J. Acup., 15, 155-165.
18 Szczerbac,J. (1977) Electric impulses as restraining measures at intervention in cattle. Acta Agrar et Silvestria (Seris Zootvch), 17, 51.
19 Terral,C. (1975) Douleur et Acupuncture, Doc. Thesis, Med. Fac., Montpellier and Rabischong et al (1975) Experimental basis for AA. Nouvelle Press Med, 4, 2021.
20 Toda,K. et al (1980) AA suppresses cortical evoked responses in somatosensory I & II areas after tooth pulp stimulation in the rat. Jap. J. Physiology, 30, 487-490.
21 Sun,Y.C. et al (1980) Veterinary AA (in cattle and horses). 17th Annual International Stockmen's School, Tucson, Arizona. Agri Services Foundation, 648 West Sierra Avenue, Clovis, CA 93612, USA.
22 Vierck,C.J. et al (1974) Prolonged hypalgesia following AP in monkeys. Life Sciences, 15, 1277-1289.
23 Yu Chuan & Hwang Yann-Ching (1990) Handbook on Chinese Veterinary AP and Moxibustion. FAO Regional Office for Asia and the Pacific, Bankok. 193pp.
APPENDIX
ANIMAL HYPNOSIS AND AA EFFECTS
Definition: "Animal hypnosis" is also called the "Still Reaction", "Death Feint", "Tonic Immobility (TI)" or the "Immobility Reflex". In this discussion it is called TI. It is a specific tonic immobility, with involuntary but reversible inhibition of spinal reflexes. It involves the selective loss of placing, righting and supporting reflexes. The animal may be alert or drowsy, depending on the nature of the induction of TI and the sensory stimulation during the trance.
Induction of TI: Strong emotions, such as intense fear can trigger TI spontaneously. (The chicken/rabbit "freezes" at the sight of the hawk/weasel). Experimental induction involves one or more of four main techniques: (a) repetitive stimulation; (b) pressure on parts of the body; (c) inversion; (d) forcible restraint until struggling ceases. Tactile and proprioceptive stimuli are the most important inducers but other stimuli, such as visual and auditory inputs, enhance the effect. Visual stimuli are most important in chickens. Enhancement and duration of TI in rabbits 2-4 kg weight is most marked if they are restrained for 5 seconds on their backs in a holder with inside measurements: base 18" X 3.25" X 4.5" high. The effect is enhanced by inserting a block to press slightly against the head. Using this method, duration of TI was 15-60+ minutes, as compared with 0.2-8.0 minutes induced by restraint on a table. TI can be enhanced greatly in duration and depth by low-level ES of certain subcortical brain sites, or of electrodes placed across the head.
Reversibility: TI is easily disrupted by stimuli and care must be taken to avoid disruption of the trance by stimuli , such as loud noise, sudden moves or accidental blows to the animal's legs or body.
Human hypnosis can induce surgical analgesia in some subjects. Animals in TI are less responsive than when awake to mild stimuli, such as sound, pinprick, electric shock. Arousal responses are elicited readily and cerebral-evoked potentials to applied pain stimuli are intact, indicating that sensory information is received. The lack of response to mild stimuli is due to motor inhibition and not to sensory inhibition (analgesia).
TI mechanisms: TI is associated with sympathetic arousal. Motor centres in the brain are inhibited but sensory cortical centres are fully active.
Young rats (up to 3 weeks of age) are good subjects but TI is difficult or impossible to induce in adult rats. Removal of the cerebral cortex in adult rats makes them very susceptible to TI. The difference in susceptibility between intact and decorticated adult rats suggests that, in that species, there is a cortical centre which inhibits a hypnogenic centre elsewhere and that the cortical centre may be underdeveloped in young rats.
Decerebration does not inhibit TI in guinea pigs and rabbits. In TI of rabbits and frogs, the loci of descending inhibition on spinal motor neurons are located in the medullary reticular formation (MRF), brainstem and cerebellum.
Opiate antagonists (naloxone etc) do not inhibit the lack of motor response to mild painful stimuli in TI. In contrast, AA is inhibited by opiate antagonists.
TI and AA activate clearly different responses, use different neurotrans-mission mechanisms, controlled by different parts of the nervous system.
1 Anon (1975) (Academy of Traditional Medicine). Outline of Chinese AP. Foreign Languages Press, Peking.
1a Anon (1980) Peking, Shanghai, Nanking Colleges of Trad. Chin. Med., with Academy of Traditional Chinese Medicines. Essentials of Chinese AP. Foreign Languages Press, Peking.
2 Anon (1974) The Principles and practice use of AA. Medicine & Health Publishing Co., Hong Kong.
3 Klide,A.M. and Kung,A.H. (1977) Veterinary AP. University of Pennsylvania Press, Philadelphia.
4 Matsumoto,T. (1973) AP of physicians. Charles C. Thomas, Springfield, Illinois.
5 Niboyet,J.E.H. et al. (1973) L'anaesthesia par l'AP. Maisonneuve.
6 Patterson,M.A. (1975) Addictions can be cured. Lion Publishers, Berkhamsted, U.K. and personal communication (1975-1980).
7 Glennie-Smith,K. (1986) Stimulation-produced analgesia for major joint surgery in elderly poor-risk patients: a feasibility study. AJA, 1987, 15, 180, ex paper to the International Medical Acupuncture Conference, London, May 4-6.
8 Ponomarenko,T.P. (1987) Experience of using electro-AP in combined analgesia. SJA&ET, 2, 42-45.
REFERENCES
1 Anon (1977) Akita AP Research Unit, Cattle Health Centre, 6-8 Nakadori, Akita-Shi, Akitaken, Japan. Electrostimulation of the thoraco-lumbar and lumbo-sacral space in surgical analgesia of cattle and pigs. Personal communication.
2 Arambarri,R. et al (1975) EAA in veterinary surgery. Revue Med. Vet. 126, 1231-1236.
3 Cheng,R.S.A. and Pomeranz,B.H. (1980) EAA is mediated by stereospecific opiate receptors and is reversed by antagonists of type 1 receptors. Life Sciences, 26, 631-638.
4 Cheng,R. et al (1980) EAA elevates blood cortisol levels in naive horses; sham treatment has no effect. Intern. J. Neuroscience, 10, 95-97.
5 Frost,E.A.M. and Hsu (1975) Neurophysiological pathways in AP. Amer. J. Acup. 3, 331-.
6 Humphries,V.J. (1977) EAA in abdominal surgery in a horse. Case history from International Veterinary Acupuncture Society (IVAS).
7 Ishizaki,S. et al (1977) EAA in high risk dogs. Jap. J. vet. Anaesth., No.8, 21-28 and World Acupuncture Congress, Paris, Summer, 1978.
8 Jacobs,S. et al (1973) EAA in the squirrel monkey. Proc. 1st International Symposium on Pain, Seattle.
9 Kadono,H et al (1977) EEG during EAA in the dog. Jap. J. Vet. Sci., 39, 539-547.
10 Kano,T et al (1976) Electroanaesthesia (EA) studies:EA produced by stimulation of sensory nerves of the scalp of rhesus monkeys. Anaesthesia and Analgesia, Current Researches, 55, 536-541.
11 Kitazawa,K. et al (1975) Experimental studies on EAA in the dog. Proc. 20th World Vet. Congress, Thessaloniki, 1657-1658 and (1975) Studies on EAA in the dog; confirmation of the effect. Jap. J. vet. Anaesth., No. 6, 7-14.
12 Kothbauer,0. (1973) EAA in teat analgesia in cows. Austrian Med. J., 28, 1037-1039 and EAA in Caesarean section in cows. Personal Communication (1977) and (1975) Wiener Tierarztl. Monatsschr., 62, 394-396.
13 Lambardt,A. (1975) AA versuche bei katzen. Der Prakt. Tierarzt, 1/1975, 33-36.
14 Lynd,F.T. (1975) AP analgesia investigations in animals. Internal report, Department of Laboratory Animal Medicine, Medical School, University of Texas, San Antonio, Texas 78284. 5 pages.
15 Matsumoto,T. et al (1974) AA in animals: selection of optimal electric stimulation. American Surgeon, October, 558-563.
16 O'Boyle,M.A. and Vajda,G.K. (1975) AA £or abdominal surgery. Mod. Vet. Pract., 56, 705-707.
17 Ralston,N.C. and Ralston,B.L. (1978) AA for cystotomy surgery in a dog. Amer. J. Acup., 6, 75-76.
17a Still,J. (1987) AP for laparotomy in dogs and cats: an experimental study: American J. Acup., 15, 155-165.
18 Szczerbac,J. (1977) Electric impulses as restraining measures at intervention in cattle. Acta Agrar et Silvestria (Seris Zootvch), 17, 51.
19 Terral,C. (1975) Douleur et Acupuncture, Doc. Thesis, Med. Fac., Montpellier and Rabischong et al (1975) Experimental basis for AA. Nouvelle Press Med, 4, 2021.
20 Toda,K. et al (1980) AA suppresses cortical evoked responses in somatosensory I & II areas after tooth pulp stimulation in the rat. Jap. J. Physiology, 30, 487-490.
21 Sun,Y.C. et al (1980) Veterinary AA (in cattle and horses). 17th Annual International Stockmen's School, Tucson, Arizona. Agri Services Foundation, 648 West Sierra Avenue, Clovis, CA 93612, USA.
22 Vierck,C.J. et al (1974) Prolonged hypalgesia following AP in monkeys. Life Sciences, 15, 1277-1289.
23 Yu Chuan & Hwang Yann-Ching (1990) Handbook on Chinese Veterinary AP and Moxibustion. FAO Regional Office for Asia and the Pacific, Bankok. 193pp.
APPENDIX
ANIMAL HYPNOSIS AND AA EFFECTS
Definition: "Animal hypnosis" is also called the "Still Reaction", "Death Feint", "Tonic Immobility (TI)" or the "Immobility Reflex". In this discussion it is called TI. It is a specific tonic immobility, with involuntary but reversible inhibition of spinal reflexes. It involves the selective loss of placing, righting and supporting reflexes. The animal may be alert or drowsy, depending on the nature of the induction of TI and the sensory stimulation during the trance.
Induction of TI: Strong emotions, such as intense fear can trigger TI spontaneously. (The chicken/rabbit "freezes" at the sight of the hawk/weasel). Experimental induction involves one or more of four main techniques: (a) repetitive stimulation; (b) pressure on parts of the body; (c) inversion; (d) forcible restraint until struggling ceases. Tactile and proprioceptive stimuli are the most important inducers but other stimuli, such as visual and auditory inputs, enhance the effect. Visual stimuli are most important in chickens. Enhancement and duration of TI in rabbits 2-4 kg weight is most marked if they are restrained for 5 seconds on their backs in a holder with inside measurements: base 18" X 3.25" X 4.5" high. The effect is enhanced by inserting a block to press slightly against the head. Using this method, duration of TI was 15-60+ minutes, as compared with 0.2-8.0 minutes induced by restraint on a table. TI can be enhanced greatly in duration and depth by low-level ES of certain subcortical brain sites, or of electrodes placed across the head.
Reversibility: TI is easily disrupted by stimuli and care must be taken to avoid disruption of the trance by stimuli , such as loud noise, sudden moves or accidental blows to the animal's legs or body.
Human hypnosis can induce surgical analgesia in some subjects. Animals in TI are less responsive than when awake to mild stimuli, such as sound, pinprick, electric shock. Arousal responses are elicited readily and cerebral-evoked potentials to applied pain stimuli are intact, indicating that sensory information is received. The lack of response to mild stimuli is due to motor inhibition and not to sensory inhibition (analgesia).
TI mechanisms: TI is associated with sympathetic arousal. Motor centres in the brain are inhibited but sensory cortical centres are fully active.
Young rats (up to 3 weeks of age) are good subjects but TI is difficult or impossible to induce in adult rats. Removal of the cerebral cortex in adult rats makes them very susceptible to TI. The difference in susceptibility between intact and decorticated adult rats suggests that, in that species, there is a cortical centre which inhibits a hypnogenic centre elsewhere and that the cortical centre may be underdeveloped in young rats.
Decerebration does not inhibit TI in guinea pigs and rabbits. In TI of rabbits and frogs, the loci of descending inhibition on spinal motor neurons are located in the medullary reticular formation (MRF), brainstem and cerebellum.
Opiate antagonists (naloxone etc) do not inhibit the lack of motor response to mild painful stimuli in TI. In contrast, AA is inhibited by opiate antagonists.
TI and AA activate clearly different responses, use different neurotrans-mission mechanisms, controlled by different parts of the nervous system.
Similarities between "Animal Hypnosis" (TI) and Acupuncture Analgesia (AA)
Differences between "Animal Hypnosis" (TI) and Acupuncture Analgesia (AA)
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