THE PREVENTION OF POSTOPERATIVE VOMITING

Abstract

Measures to prevent sickness which are designed to modify known and suspected influencing factors are of limited value. The anaesthetic techniques at present employed are unlikely to cause sickness to any appreciable extent. It seems that the once popular habit of using analgesic drugs such as pethidine to supplement anaesthesia is a cause of postoperative sickness and the practice can readily be avoided by the use of halothane or muscle relaxants according to the situation. Omission of pethidine or similar drugs before operation, or the employment of a reduced dose of pethidine appears to be a satisfactory way of dealing with a further influence. Of the many other factors, most are of unknown importance or else cannot be modified in any way by the anaesthetist. For specific cases, complete pre-operative avoidance of analgesics is advised and, if desired, pentobarbitone or promethazine are satisfactory alternatives. The use of haloperidol and perphenazine by injection during anaesthesia seems at present the most certain way of preventing sickness. Contributory measures can include the avoidance of rough handling in transportation and of too early movement on the part of the patient. The role of food and drinks early in the postoperative period is not well defined, but is undoubtedly a factor in causing sickness in morphinized subjects. Whether this is, in fact, due to vestibular stimulation accompanying bodily movement rather than to the actual ingestion of fluid or food is open to debate. Even after all measures have been taken, there is always the possibility that drugs given to relieve pain late in the postoperative period will excite vomiting for which treatment with anti-emetic drugs will be needed.