Background: We tested the hypothesis that intramuscularly administered ephedrine prevents postoperative nausea and vomiting. Ephedrine is cheap, and for this indication poorly documented.
Methods: One hundred and nine patients undergoing elective abdominal hysterectomy under general anaesthesia were studied in a randomized, double-blind placebo-controlled study. Ten minutes before the end of the procedure patients received either ephedrine 0.5 mg/kg i.m. or placebo. The patients were closely observed for 24 h for postoperative nausea or vomiting (PONV) and received a standardized two-step antiemetic treatment of i.v. metoclopramide 10 mg, supplemented with ondansetron 4 mg i.v. if needed.
Results: The ephedrine treated patients had significantly less nausea, retching and vomiting, and need of antiemetic rescue during the first 3 h postoperatively compared with the placebo patients. No difference between the groups was evident in the 3-24 h postoperative observation period. All the patients with PONV during 0-3 h experienced PONV in the 3-24 h period. Treatment or prophylaxis with one drug was less efficient than two or more drugs combined. No significant differences in hypotension, tachycardia or other side-effects between the groups were noted.
Conclusion: Ephedrine 0.5 mg/kg i.m. administered at the end of abdominal hysterectomy has a significant antiemetic effect during the first 3 h after administration with no evident side-effects.