Dose-range effects of propofol for reducing emetic symptoms during cesarean delivery

Abstract

OBJECTIVE: To evaluate the efficacy and safety of propofol at subhypnotic doses for reducing emetic symptoms in parturients undergoing cesarean delivery under spinal anesthesia. METHODS: In a randomized, double-masked trial, 80 patients received lidocaine intravenously 0.1 mg/kg (for injection pain relief) followed by either placebo or propofol at three different doses (0.5 mg/kg per hour, 1.0 mg/kg per hour, 2.0 mg/kg per hour) ( n = 20 in each group) immediately after clamping of the umbilical cord. Emetic episodes and safety assessments were performed during spinal anesthesia for cesarean delivery. To estimate a sufficient sample size, it was calculated that 20 patients per group would be required with α = .05 and β = .2. RESULTS: The rate of patients experiencing no emetic symptoms in an intraoperative, postdelivery period was 45% with propofol 0.5 mg/kg per hour ( P = .5), 80% with propofol 1.0 mg/kg per hour ( P = .011), and 80% with propofol 2.0 mg/kg per hour ( P = .011), compared with placebo (40%). No clinically serious adverse events caused by the study drugs were observed. CONCLUSION: Propofol 1.0 mg/kg per hour is the minimum effective subhypnotic dose for reducing emetic symptoms during cesarean delivery. Increasing the dose to 2.0 mg/kg per hour provides no further benefit.