Optimal dose of prophylactic intravenous ephedrine for spinal-induced hypotension during cesarean section

Objectives: The objective of this study was to compare the efficacy of 10, 15, and 2Omg bolus doses of prophylactic IV ephedrine for prevention of maternal hypotension associated with spinal anesthesia for cesarean section. Study Design: A prospective, quasi experimental study. Place & Duration: The study was conducted at Department of Anesthesiology & Intensive Care, Shalamar Hospital Lahore (Pakistan), and was completed in six months period from January to June 2008. Methodology: Ninety parturients of ASA grade I and II, receiving spinal anesthesia for elective C-section were included in this study. They were randomly divided into three groups. Group-I received 10mg, Group-II 15mg, and Group-III 20mg prophylactic IV ephedrine immediately atter administration of spinal anesthesia. Intra operative hemodynamic changes were recorded and the data were analyzed. Results: Incidence of hypotension was significantly higher in Group-I parturients receiving a lOmg prophylactic dose of ephedrine than in Group-II and Group-III parturients receiving 15mg or 20mg of ephedrine respectively (53.3% versus 13.3% and 3.3% respectively). There was however, a significantly higher incidence of reactive hypertension in Group-II parturients (46.7%). Conclusions: 15mg bolus dose of prophylactic IV ephedrine can effectively prevent spinal induced maternal hypotension during cesarean section without adverse effects like reactive hypertension.