J. G. Bovill

The taming of ketamine

Ketamine first became available in Britain for clinical trial in January 1970, but early results revealed a high incidence of delirium and unpleasant dreams during the recovery period.’ These sequelae were particularly severe in unpremedicated patients undergoing minor gynaecological operations lasting less than 15 min. Published studies have shown the importance of the dose of ketamine,’ presupplementation of a n a e s t h e ~ i a , ~ . ~ sex of the ~ a t i e n t , ~ and the type and duration of in determining the nature and severity of sequelae. Fig. 1 summarizes the incidence of undesired effects found in the studies from this centre and shows the need for further investigations. Ketamine possesses many unique properties, such as ability to be given by the intravenous or intramuscular route, and the production of profound analgesia without cardiovascular depression. These could, in certain circumstances, make it superior as an induction agent to any other at present in clinical use, provided the post-operative problems could be minimized. It was thus felt that a study of adjuvants which would further reduce these sequelae was indicated, and this paper shows how acceptable results can be obtained in general surgical patients.