The effect of 10 and 20 mg intravenous ephedrine on prevention of hypotension due to spinal anesthesia in cesarean section

Hypotension is one of the common complications of spinal anesthesia. Ephedrine with sympathomimetic effects is the selective vasopressor in obstetric. The aim of this study was to compare the effect of different doses of ephedrine on hypotension due to spinal anesthesia. This randomized double-blind clinical trial included 120 parturient patients with ASA Ι and П scheduled for cesarean section under spinal anesthesia at Fatemy Hospital of Hamedan in 2008.The patients were divided into three groups. Immediately after spinal anesthesia, the patients randomly received 10 mg ephedrine, 20 mg ephedrine, or placebo intravenously. Then vital signs were recorded every minute for 5 minutes and after delivery every 10 minutes till the end of the surgery. Incidence of hypotension in 10 mg ephedrine, 20mg ephedrine, and placebo groups was 37.5,12.5, 85%, respectively (P<0.001). The difference in the prevalanceof hypotension was significant between the three groups (P<0.05).Based on Chi2 test, the prevalence of hypotension in 20 mg ephedrine group was less than 10 mg ephedrine group, and in the 10mg ephedrine group it was less than the placebo group (P<0.05). Intravenous injection of 10mg and 20mg ephedrine to parturient patients undergoing cesarean section reduces the incidence of hypotension, though thisdecrease is more significant with 20 mg ephedrine.