Tim occurrence of vomiting in the post-operative period has been one of the most c6nstantly observed complicatmns of the anaesthetac era. This complication is usually simply annoying and unpleasant, although occasionally the patient may in this manner lose sufficient fluid and electrolyte to prejudice his recovery. Many of the causes remain obscure and it has been for generations the hope of anaesthetasts, surgeons and patients alike that this complication of the postoperative period might be eliminaied, or abated. Each new anaesthetic agent and techmque has been carefully evaluated for its ififluence in this respect. Despite all such research and evaluation, vomiting has remained a common and unpleasant feature of the post-operatave period an a significant proportion of surgical patients Lee (1) states that vomiting may be influenced by one or more of the following factors: (a) anaesthetic agent and techt~tque (b) type of patient (e) condition

Vo~rriNc during the immediate postoperalave period is a frequent complication of anaesthesia m children Dimenhydrinate, promethazme hydrochloride, and chlorpromazine have all been recommended as effeclave anti-emetic drugs (1, 2, 3). A comparison o; the chmcal efficacy of these three agents was made with a carefully selected and controlled group of patients.A group of patients undergoing operalaon for correction of squint was chosen for this study for the following reasons:1. They were reputed to have a relatively high incidence of post-anaesthetic vomzlang, a prerequisite for ~he demonstratmn of anti-emetic action in a relatively small series of cases 2. There was no operatJve interference with or disease of the gastro-intestinal tract.3. All operations lasted between one-half and one hour. 4. All pataents were on the same ward with the result that observations were made by the same nursing personnel throughout the proleet, 5. All cases were electave and had receaved nothing by mouth for at least four hours prior to induction, ~md had received no solid food since the evening prior to operation.The cases used in the study were drawn from both public and private patients of certain eye-surgeons and were elther treated or placed in the control group on a completely random basis.The first comparison was made between 40 cases treated with dimenhydrinate and 40 untreated controls. Towards the completaon of this series, optimistic reports of the effectiveness of promethazine hydrochlorlde and chlorpromazine prompted us to conduct a second serms consislang ~f 20 cases treated with promethazme hydrochlorlde, 25 casestreated with chlorpromazine and 20 untreated controls.ANAESTHETIC MANAGEMENT All cases were treated lm the following routine manner: 1. All had atropine alone for preoperative medication, and narcotic drugs, alleged to contribute to post-anaesthetic vomiting, were not administered.2. Peroral endotracheal mtubation was performed m all cases following induchon with pentothal sodium and relaxant whenever venepuncture was leasable, or, in smaller children, with ethyl chloride--ether sequence.