One hundred and twelve women undergoing elective orthopaedic surgery under
enflurane anaesthesia were given, in a double-blind random fashion, 2.5 mg of
droperidol i.m. before anaesthesia, or 1.25 mg of
droperidol or a saline placebo i.v. at the end of anaesthesia in an attempt to prevent post-operative
vomiting. The administration of
droperidol 1.25 mg (for those receiving initially 1.25 mg of
droperidol) or saline (for those receiving initially 2.5 mg of
droperidol or saline) was repeated i.m. during the 24 post-operative hours in a blind manner if the patient complained of
nausea, retched or vomited. Significantly fewer patients (P less than 0.05) given i.m. or i.v.
droperidol had
emetic symptoms than patients given saline. Furthermore, 51% of the patients given saline needed additional doses of saline, whereas only 27% of the patients given i.m. and 36% of the patients given i.v.
droperidol required a second dose (P less than 0.05 between groups). More of the patients given saline (23%) than those given
droperidol (8% to 9%), as a blind
drug (P less than 0.05), needed to be given additional
droperidol as a known
anti-emetic because of the failure of the blind
drug to prevent or treat symptoms. It is concluded that
droperidol given either as a single dose of 2.5 mg i.m. or in repeated doses of 1.25 mg i.v. is effective in the prevention and treatment of post-operative
nausea and
vomiting after
enflurane anaesthesia.