Evaluation of two antiemetic agents during outpatient gynaecological surgery

Thirty-two adult female ASA I patients (American Society of Anesthesiologists' grading) undergoing voluntary termination of pregnancy (VTP) under general anaesthesia were randomly divided into three groups. Patients received 0.6 mg/kg pentazocine intravenously five minutes prior to induction of anaesthesia along with either isotonic saline, or promethazine 0.5 mg/kg or metoclopramide 0.2 mg/kg. Anaesthesia was induced with intravenous thiopentone and maintained with nitrous oxide in oxygen and boluses of thiopentone. Vomiting and sedation were scored at the end of anaesthesia, one hour later and at the time of discharge. The mean vomiting score was comparable in the three groups. Though the mean dose of thiopentone used was significantly less in the promethazine group, the sedation scores and the duration of stay in the clinic were comparable in all the groups. It is concluded that promethazine and metoclopramide in the doses used are ineffective as antiemetic agents in outpatient gynaecological patients.