Correspondence Anaesthesia for Adenotonsillectomy

Sir,—I would like to offer my congratulations to Dr. Andrew Doughty for his excellent paper entitled " Anaesthesia for Adenotonsillectomy" (Brit. J. Anaesth. (1957), 29, 407). As Dr. Doughty so rightly points out, the child should be entitled to receive the maximum benefits from the improvements in anaesthetic techniques which have taken place during recent years. I cannot, however, agree with Dr. Doughty's outright condemnation of the oral route of premedication, although I decided some time ago that quinalbarbitone was a too long acting drug to use for the purpose. Having made this decision I began to investigate the use of methylpentynol as a premedicant for children undergoing adenotonsillectomy and have recently completed a series of 500 cases. I did not use the papaveretum and scopolamine combination as advocated by Dr. Doughty because, although I agree that children tolerate this combination well in the correct dosage, some depression of the respiratory centres and cough reflexes must result from the use of these drugs, and such depression I consider undesirable in children undergoing operations upon the nose and throat. The method of premedication I used in my series was as follows: The child was given methylpentynol (Oblivon Elixir) H hours before operation and atropine sulphate subcutaneously i hour before operation. It is important that an oral premedicant is given well before the dose of atropine or scopolamine being used, otherwise absorption from the stomach will be delayed. Children weighing from 21 to 35 lb received two teaspoonfuls of the elixir (500 mg of methylpentynol). Children weighing from 36 to 55 lb received three teaspoonfuls of the elixir (750 mg methylpentynol), and children weighing over 55 lb received four teaspoonfuls of the elixir (1000 mg methylpentynol). This corresponds very roughly to a dose of 18 mg per pound body weight. 527 At the beginning of the series all children were anaesthetized by the " standard method "; i.e. ethyl chloride and open ether or nitrous oxide induction followed by nitrous oxide, oxygen and ether insufflated down the side tube of a Boyle-Davis gag. It was then decided to investigate the intravenous technique, using thiopentone for induction followed by suxamethonium chloride, intubation, and maintenance with nitrous oxide, oxygen and minimal ether. At first this technique was used only for the older children and then, as the results proved very satisfactory, it was gradually adopted for the younger children as well. The series of 500 cases premedicated with methylpentynol and atropine is therefore composed of 325 patients anaesthetized by the ether insufflation technique and 175 patients anaesthetized by the intravenous technique. Twelve patients of the series arrived in the anaesthetic room asleep and anaesthesia was induced smoothly without the patient awakening. Four hundred and thirty-four patients arrived awake and in an apparently peaceful frame of mind and were quiet and co-operative during the induction, whichever method was used. The remaining 54 patients arrived in an apprehensive state of mind but 39 of these could be reassured; this was a notable feature following methylpentynol, and induction was carried out smoothly. Fifteen patients out of the 500 remained nervous and unco-operative and the effects of the methylpentynol were not considered satisfactory; only 2 of these, however, were being induced by the intravenous route.