1307 TAKING FAMILY HISTORY OF ANÆSTHETIC PROBLEMS
SIR,—The sheets used for history taking in antenatal clinics seldom have a space for specific inquiry about anaesthetic problems’ and patients scheduled for surgery are frequently not asked about previous anxsthetics or about problems associated with anesthetics and they are hardly ever asked about abnormal reactions to anesthesia in their siblings. A 19-year-old primigravida required csesarean section for failure to progress with a breech presentation. She had no history of operations or anesthesia. Anaesthesia was induced with thiopentone and suxamethonium and maintained with nitrous oxide, oxygen, and halothane. 30 min after reversal of anoesthesia with atropine and neostigmine and extubation, the patient was noted to be cyanosed with shallow regular respiration, a pulse-rate of 120/min and a blood-pressure of 160/90 mm Hg. She could open her eyes on command and there was no clinical evidence of neurological deficit. She was reintubated and artificial ventilation was maintained with 50:50 nitrous oxide and oxygen. She was transferred to intensive care. Serum electrolyte concentrations, bicarbonate, urea, and glucose were normal. Artificial ventilation was continued for 7 h by which time good muscle tone and respiratory efforts had returned. With the patient breathing via an MC mask with oxygen flow at 4 1/min, the PaC02 was 12-1kPa and the Pa02 27-6 kPa. Subsequent progress was normal and recovery com-
plete. On careful questioning of the patient’s mother it was found that the patient’s sister had had an abnormal reaction to a dental anesthetic, following which mother and daughter had been investigated. The sister’s records showed her to be homozygous for the atypical form of cholinesterase. The mother was heterozygous for the usual and atypical forms of cholinesterase with an E1uE1a genotype. The patient herself and her brother and father had declined to attend for investigation at that time. The patient’s blood was sent for serum cholinesterase studies; she was found homozygous for the atypical form of cholinesterase with an E aE,a genotype. Since the prevalence of abnormal sensitivity to suxamethonium is 1 in 4000-5000,2 not greatly differing from that of spina bifida (1 in 3000) where a family history is regularly sought, we consider it essential to inquire, at the time of booking, into the anesthetic experiences of both the patient and other family members to avoid a similar recurrence.
Maternity Hospital Leeds LS2 9LW
at
Leeds,
P. SINGH K. W. HANCOCK
NEURAL PLASTICITY AND ANALGESIA: ASPECTS OF THE SAME PHENOMENON?
SiR,-Endogenous opiates are thought to mediate analgesia produced by placebo,’ acupuncture,and nitrous oxide,s but not that induced by hypnosis.6,’ For several years we have been studying the efficacy of subcutaneous nerve stimulation (SCNS) in various pain syndromes. We now report that SCNS 1. Browne JCM, Dixon G. Ante-natal care. 11th ed. London: Churchill Livingstone, 1978: 429-32. 2. Harris H, Whittaker M. The genetics of drug sensitivity with special reference to suxamethonium. In: Morgan JL, ed. Enzymes and drug action (Ciba Found Symp). Boston: Little Brown. 1962: 301-13. 3. Levine JD, Gordon NC, Fields HL. The mechanism of placebo acupuncture. Lancet 1978; ii: 654-56. 4. Mayer DJ, Price DD, Rafii A, Barber J. Acupuncture analgesia: Evidence for activation of a pain inhibitory system as a mechanism of action. In: Bonica JJ, Albe-Fessard D, eds. Advances in pain research and therapy vol I: Proceedings of the First World Congress on Pain. New York, 1976: 751-59. 5. Berkowitz BA, Ngai SH, Finck AD. Nitrous oxide "analgesia" resemblance to opiate action. Science 1976; 194: 967-68. 6. Barber J, Mayer D. Evaluation of the efficacy and neural mechanism of a hypnotic analgesia procedure in experimental and clinical dental pain. Pain 1977; 4: 41-8. 7. Nasrallah HA, Holley T, Janowsky DS. Opiate antagonism fails to reverse hypnotic-induced analgesia. Lancet 1979; ii: 1355.
EFFECT OF SCNS ON CLONUS
(BOUNCES)
suppresses clonus in patients with spastic paraparesis for several hours, and in some cases permanently. Such prolonged alteration in the threshold of spinal motoneurons as a result of a procedure that produces effective analgesia may provide a clue to understanding the neurophysiology of pain. Electrical or manual stimulation of cutaneous nerves in the foot and hands elicits clonus in spastic patients, while stimulation of placebo points has no effect. After one hour, habituation occurs, and clonus can no longer be elicited by stimulation. We have recorded these findings on film, and the data from a typical patient are presented in the table. The effect is not produced by placebo or suggestion because it can be demonstrated on the first trial in "naive" patients who are being treated for pain. The suppression begins 20 min after treatment and is greatest at 1 h. Suppression, partial or total, lasts 3 h. In the first few sessions the threshold for eliciting clonus is raised. Several attempts are needed and then the number of jerks increases, a phenomenon reminiscent of temporal summation. Such summation never occurs before a treatment. Progressively shorter treatments are required, and inhibition lasting for up to 1 week can occur after eight treatments.
Inhibition of clonus is not mimicked by doses of morphine large enough to cause marked respiratory depression (30 mg intravenously); administration of naloxone (0-4 mg i.v.) does not reverse suppression, indicating that opiate receptors are involved in the initiation of this response. Clonus suppression parallels analgesia, and may represent an objective, quantifiable "bioassay" for its induction. These observations support the notion that CNS reorganisation of function is a prerequisite for prolonged pain relief. not
Department of Anesthesiology, U.C.L.A. School of Medicine, Los Angeles, California 90024, U.S.A.
JUDITH B. WALKER RONALD L. KATZ
PÆDIATRIC SURGEONS ARE NECESSARY
SIR,-It is often said that pasdiatric surgeons
are not neces-
general surgeons can operate on children quite adequately. Recently a young boy was referred with a right inguinal hernia which was repaired (see figure). On his left side he has a hideous oblique inguinal incision, as commonly practised by general surgeons. Although the first operation had sary and that
Cosmetic aftermath of hernia repair.
SIR,—The sheets used for history taking in antenatal clinics seldom have a space for specific inquiry about anaesthetic problems’ and patients scheduled for surgery are frequently not asked about previous anxsthetics or about problems associated with anesthetics and they are hardly ever asked about abnormal reactions to anesthesia in their siblings. A 19-year-old primigravida required csesarean section for failure to progress with a breech presentation. She had no history of operations or anesthesia. Anaesthesia was induced with thiopentone and suxamethonium and maintained with nitrous oxide, oxygen, and halothane. 30 min after reversal of anoesthesia with atropine and neostigmine and extubation, the patient was noted to be cyanosed with shallow regular respiration, a pulse-rate of 120/min and a blood-pressure of 160/90 mm Hg. She could open her eyes on command and there was no clinical evidence of neurological deficit. She was reintubated and artificial ventilation was maintained with 50:50 nitrous oxide and oxygen. She was transferred to intensive care. Serum electrolyte concentrations, bicarbonate, urea, and glucose were normal. Artificial ventilation was continued for 7 h by which time good muscle tone and respiratory efforts had returned. With the patient breathing via an MC mask with oxygen flow at 4 1/min, the PaC02 was 12-1kPa and the Pa02 27-6 kPa. Subsequent progress was normal and recovery com-
plete. On careful questioning of the patient’s mother it was found that the patient’s sister had had an abnormal reaction to a dental anesthetic, following which mother and daughter had been investigated. The sister’s records showed her to be homozygous for the atypical form of cholinesterase. The mother was heterozygous for the usual and atypical forms of cholinesterase with an E1uE1a genotype. The patient herself and her brother and father had declined to attend for investigation at that time. The patient’s blood was sent for serum cholinesterase studies; she was found homozygous for the atypical form of cholinesterase with an E aE,a genotype. Since the prevalence of abnormal sensitivity to suxamethonium is 1 in 4000-5000,2 not greatly differing from that of spina bifida (1 in 3000) where a family history is regularly sought, we consider it essential to inquire, at the time of booking, into the anesthetic experiences of both the patient and other family members to avoid a similar recurrence.
Maternity Hospital Leeds LS2 9LW
at
Leeds,
P. SINGH K. W. HANCOCK
NEURAL PLASTICITY AND ANALGESIA: ASPECTS OF THE SAME PHENOMENON?
SiR,-Endogenous opiates are thought to mediate analgesia produced by placebo,’ acupuncture,and nitrous oxide,s but not that induced by hypnosis.6,’ For several years we have been studying the efficacy of subcutaneous nerve stimulation (SCNS) in various pain syndromes. We now report that SCNS 1. Browne JCM, Dixon G. Ante-natal care. 11th ed. London: Churchill Livingstone, 1978: 429-32. 2. Harris H, Whittaker M. The genetics of drug sensitivity with special reference to suxamethonium. In: Morgan JL, ed. Enzymes and drug action (Ciba Found Symp). Boston: Little Brown. 1962: 301-13. 3. Levine JD, Gordon NC, Fields HL. The mechanism of placebo acupuncture. Lancet 1978; ii: 654-56. 4. Mayer DJ, Price DD, Rafii A, Barber J. Acupuncture analgesia: Evidence for activation of a pain inhibitory system as a mechanism of action. In: Bonica JJ, Albe-Fessard D, eds. Advances in pain research and therapy vol I: Proceedings of the First World Congress on Pain. New York, 1976: 751-59. 5. Berkowitz BA, Ngai SH, Finck AD. Nitrous oxide "analgesia" resemblance to opiate action. Science 1976; 194: 967-68. 6. Barber J, Mayer D. Evaluation of the efficacy and neural mechanism of a hypnotic analgesia procedure in experimental and clinical dental pain. Pain 1977; 4: 41-8. 7. Nasrallah HA, Holley T, Janowsky DS. Opiate antagonism fails to reverse hypnotic-induced analgesia. Lancet 1979; ii: 1355.
EFFECT OF SCNS ON CLONUS
(BOUNCES)
suppresses clonus in patients with spastic paraparesis for several hours, and in some cases permanently. Such prolonged alteration in the threshold of spinal motoneurons as a result of a procedure that produces effective analgesia may provide a clue to understanding the neurophysiology of pain. Electrical or manual stimulation of cutaneous nerves in the foot and hands elicits clonus in spastic patients, while stimulation of placebo points has no effect. After one hour, habituation occurs, and clonus can no longer be elicited by stimulation. We have recorded these findings on film, and the data from a typical patient are presented in the table. The effect is not produced by placebo or suggestion because it can be demonstrated on the first trial in "naive" patients who are being treated for pain. The suppression begins 20 min after treatment and is greatest at 1 h. Suppression, partial or total, lasts 3 h. In the first few sessions the threshold for eliciting clonus is raised. Several attempts are needed and then the number of jerks increases, a phenomenon reminiscent of temporal summation. Such summation never occurs before a treatment. Progressively shorter treatments are required, and inhibition lasting for up to 1 week can occur after eight treatments.
Inhibition of clonus is not mimicked by doses of morphine large enough to cause marked respiratory depression (30 mg intravenously); administration of naloxone (0-4 mg i.v.) does not reverse suppression, indicating that opiate receptors are involved in the initiation of this response. Clonus suppression parallels analgesia, and may represent an objective, quantifiable "bioassay" for its induction. These observations support the notion that CNS reorganisation of function is a prerequisite for prolonged pain relief. not
Department of Anesthesiology, U.C.L.A. School of Medicine, Los Angeles, California 90024, U.S.A.
JUDITH B. WALKER RONALD L. KATZ
PÆDIATRIC SURGEONS ARE NECESSARY
SIR,-It is often said that pasdiatric surgeons
are not neces-
general surgeons can operate on children quite adequately. Recently a young boy was referred with a right inguinal hernia which was repaired (see figure). On his left side he has a hideous oblique inguinal incision, as commonly practised by general surgeons. Although the first operation had sary and that
Cosmetic aftermath of hernia repair.
