RESUMO
To ameliorate post spinal anesthesia hypotension in patients undergoing cesarean section. To compare the incidence of maternal hypotension associated with spinal anesthesia for cesarean section when intravenous [IV], intramuscular [IM] or oral prophylactic boluses of ephedrine were used. Prospective randomized double blind Department of anesthesiology, Zainibiae Hospital, Shiraz University, Iran. June 2004 to November 2005. 60 ASA grade I-II pregnant mothers were enrolled. Spinal anesthesia was performed using 60-70 mg of 5% solution of lidocaine. The patients were divided into three equal groups [n=20]. Oral and IM ephedrine [25 mg] was administered to the first two groups 30 to 60 minutes before induction of anesthesia [Group A and B, respectively]. In the last 20 patients, IV Ephedrine [25 mg] was administered immediately after induction of spinal anesthesia [Group C]. Maternal blood pressure and pulse rate was checked every 2 minutes. Hypotension was promptly treated with 10-mg ephedrine boluses. Both IM and IV prophylactic doses of ephedrine significantly decreased the incidence of hypotension, compared to oral prophylactic dose of ephedrine [4/20 and 0/20 in the IM and IV ephedrine groups, respectively vs. 9/20 in the oral ephedrine group [p < 0.05]]. Oral prophylactic dose of ephedrine is not effective in preventing hypotension in pregnant women undergoing cesarean section with spinal anesthesia. Therefore, we only recommend a single bolus of IV ephedrine with a dose of 25mg