Abstract
A prospective, randomized placebo-controlled study was undertaken to compare the effects on heart rate and blood pressure during surgery and on the incidence of nausea, vomiting and headache after surgery of IM prochlorperazine 0.2 mg.kg-1, IV prochlorperazine 0.1 mg.kg-1 and IV ondansetron 0.06 mg.kg-1 given at induction of general anaesthesia to patients undergoing septorhinoplasty. The effects of the test drugs after administration on heart rate and blood pressure were similar, as were the incidences of retching and vomiting in the recovery ward after each test drug. Postoperatively, compared with placebo (7%), nausea per se was most frequent in those given IV prochlorperazine (25%, P<0.01), and less frequent in those given IM prochlorperazine (2%) and IV ondansetron (15%). Vomiting per se was reduced from 24% to 7% (P<0.025) by IV prochlorperazine and to 4% (P<0.0005) by IV ondansetron. The incidence of nausea with vomiting was reduced from 35% to 15% (P<0.025), 16% (P<0.05) and 11% (P<0.005) by IM prochlorperazine, IV prochlorperazine and IV ondansetron respectively. IM prochlorperazine and IV ondansetron increased the frequency (from 35% to 64%, P<0.0005 and to 71%, P<0.0005, respectively) of those experiencing no PONV and delayed the onset of PONV, but only IM prochlorperazine reduced the severity of postoperative vomiting. Headache was frequent in the control (69%), IV prochlorperazine (62%) and IV ondansetron (69%) groups, and least frequent after IM prochlorperazine (53%; P<0.05 versus IV ondansetron). It is concluded that these drugs have no adverse cardiovascular effects within 10 minutes of administration, IM prochlorperazine and IV ondansetron reduce PONV more effectively than IV prochlorperazine and postoperative headache after septorhinoplasty occurs less frequently in those given IM prochlorperazine than in those given IV ondansetron.