Subhypnotic doses of midazolam prevent nausea and vomiting during spinal anesthesia for cesarean section

We aimed to evaluate the efficacy of subhypnotic doses of midazolam and propofol for peripartum nausea and vomiting during regional anesthesia for elective cesarean section in order to prevent emesis in at least 50% of patients.

A prospective, double blind, placebo-controlled study was carried out. Patients were randomly allocated to one of three groups to receive placebo (saline, N=28), propofol (20 mg bolus and 1.0 mg x kg(-1) x h(-1) infusion, N=30), and midazolam (1 mg bolus and 1.0 mg x h(-1) infusion, N=30) at subhypnotic doses intravenously (i.v.) immediately after the umbilical cord was clamped. Bupivacaine hydrochloride (8-10 mg) and fentanyl (10 microg) were injected into the intervertebral space for spinal anesthesia. Blood pressure was monitored at 2 min intervals and intraoperative postdelivery emetic episodes and ephedrine consumption were recorded. The study was carried out at the Anesthesiology Department, Hacettepe University, Turkey, hospitalized care. We included 90 parturients with ASA physical status I and II between the ages of 20 and 38 years undergoing spinal anesthesia for elective cesarean delivery to evaluate the efficacy of subhypnotic doses of propofol and midazolam and, in particular, the incidence of nausea, retching, and vomiting intraoperatively.

The incidence of nausea, retching, and vomiting was significantly higher in the control group, compared to the propofol and midazolam groups. Total ephedrine consumption was significantly higher in the control group compared to the propofol and midazolam groups.

A subhypnotic dose of midazolam (1 mg x h(-1)) was as effective as the subhypnotic dose of propofol (1 mg x kg(-1) x h(-1)) for the prevention of nausea and vomiting in parturients undergoing cesarean section under spinal anesthesia.