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.

1308 been done five weeks

previously,

there is

a

very

unpleasant

scar.

In any case, when a hernia is found on the left, both groins should be explored, for right-sided hernias are more common than left-sided ones. There is still a placefor paediatric surgery. Hey Children’s Hospital, Liverpool L12 2AP Alder

R. E. CUDMORE

Medicine and the Law Negligence or Error of Judgment? A 30-year-old primigravida, regarded as at high risk during pregnancy, was treated at a specialist maternity unit in 1969. After 22 hours of labour she was attended by a senior obstetric registrar, who thought that the pelvic dimensions might be insufficient for normal delivery. He began a trial of labour. After pulling with Simpson’s forceps for five or six contractions, he decided that a vaginal delivery would be too traumatic and he undertook a cxsarean section. The child was not breathing and spontaneous respiration was established after 35 minutes of ventilation and other resuscitative measures. Cerebral palsy and mental deficiency were later diagnosed and the child would need constant care and attention all his life. An action, brought in the name of the child by the mother as next friend, claimed damages for negligence against the obstetrician and the regional health authority. Mr Justice Bush found that the brain damage suffered by the child had been caused by asphyxia occurring during the 40 minutes between the beginning of the trial of forceps and the delivery by cassarean section, and he held that the obstetrician had been guilty of negligence and awarded £100 000. The obstetrician

appealed. Lord DENNING, Master of the Rolls, said that the great preof eminent medical opinion was that neither the obstetrician nor the hospital had been negligent. A report to the contrary by two retired professors, which had been the justification for the continuance of the action, suffered, in the first place, from the way it had been prepared. It was the result of long conferences between the two professors and counsel and was actually "settled" by counsel. In short, it wore the colour of special pleading rather than an impartial report. There was also evidence of serious mistakes in the report itself. Its defects were so great that it could not stand against the other reports. However, the judge had decided against the obstetrician largely on a report made about two months after the event by the professor in charge of the maternity unit, in which he said: "Descent, however, did not follow traction and in the interest of the child the head was disimpacted prior to speedy delivery by cxsarean section. The baby, alas, was seriously affected by this well-conducted trial of labour and forceps. Possibly at cæsarean section the disimpaction of the head was critical and cerebral haemorrhage followed." The judge refused to accept the professor’s explanation that by "disimpacted" he meant to denote no more than that some slight force had been needed to free the child’s head. But the report itself refuted any suggestion of negligence and it would not be right, therefore, to read it as containing an admission of negligence. The judge had read too much into the word "disimpacted". The. other reason for the judge’s conclusion that the obstetrician had "pulled too hard and too long so that the fetus became wedged or stuck" was his interpretation of part of the mother’s evidence. That was that when the forceps were applied the mother was pulled toward the bottom of the bed in a manner and with such force as to be inconsistent with a trial of forceps properly carried out. The mother’s evidence had been shown

ponderance

be wrong in so many respects that it was not right to accept it in contradiction of all those present at the time. Those two points were quite insufficient to convict the obstetrician of negligence, and his Lordship would reverse the judge’s finding. The obstetrician had acted with every skill and care. The damage to the child was one of those unfortunate things which happened in the best of hospitals, despite all care. In a highrisk case, damage during birth was quite possible even though all care was used. No inference of negligence should be drawn from it. The judge’s reference to "the very high standard of professional competence that the law requires" suggested that the law made no allowance for errors of judgment. That would be a mistake. Else there would be a danger, in all cases of professional men, of their being made liable whenever something happened to go wrong. If medical men were to be found liable whenever they did not effect a cure--or anything untoward happened-it would do a great disservice to the profession itself. In the United States "medical malpractice" cases were very worrying, especially as they were tried by juries who had sympathy for the patient and none for the doctor who was insured. Damages were colossal and insurance premiums became very high. Experienced practitioners were known to have refused to treat patients for fear of being accused of negligence. Such consequences must be avoided in England. It must be firmly said that, in a professional man, an error of judgment is not negligence. To test it, his Lordship would suggest asking the average competent and careful practitioner: "Is this the sort of mistake that you yourself might have made?" If he said: "Yes, even doing the best I could, it might have happened to me," then it was not negligence. Applying that test, even accepting the judge’s view that the obstetrician pulled too hard and too long, it was not negligent. It was at worst an error of judgment. His Lordship would allow the appeal. Lord Justice LAWTON, concurring, said that the standard of proof on the plaintiff was that required in civil cases-namely, proof on a balance of probabilities, but "the more serious the allegation the higher the degree of probability that is required". Allegations of negligence against medical practitioners should be considered serious. If courts made findings of negligence on flimsy evidence or regarded failure to produce an expected result as strong evidence of negligence, doctors were likely to protect themselves by what had become known as defensive medicine-that was, adopting procedures which were not for the benefit of the patient but safeguards against the possibility of the patient making a claim for negligence. It was common knowledge that babies on whom obstetrical forceps were used sometimes suffered injury, fortunately, in most cases, only slight. The doctor in each case had to decide for himself whether to apply forceps and continue to do so or to stop and deliver the baby by by caesarean section. It followed that the evidence required careful examination. The judge should not have accepted that the mother could give any worthwhile evidence on the question whether the obstetrician pulled too hard and too long. The judge turned her account of what had happened, which could not physically have taken place, into one which could. It could not be right that a finding of negligence against an experienced obstetrician should rest on a speculation as to what might have happened to the mother. There was nothing in the obstetrician’s evidence to justify the inference that he had got the head wedged or stuck and nothing to indicate that the judge had rejected any part of his evidence. The judge had merely associated him with the use of the word "disimpacted" in the report by the head of the unit. There was evidence pointing to the opposite inference: the delivery by caesarean was rapid and no signs of trauma on the child’s body were noted after delivery. There was no justification for the judge’s finding based on the report. The most which had been proved was that when the obstetrician asked himself whether he should go on using forceps or proceed at once to cassarean section he gave himself an answer which subsequent events showed was wrong. Being wrong was not the same as being negligent and negligence had not been proved. to