Comparison of bolus phenylephrine, ephedrine and mephentermine for maintenance of arterial pressure during spinal anesthesia in cesarean section.

Hypotension is common following spinal anesthesia. Various vasopressors have been indicated to prevent it. The study compares three such agents namely phenylephrine, ephedrine and mephentermine. The study included 90 patients undergoing elective and emergency cesarean section who developed hypotension following subarachnoid blockade. Parturient were randomly divided into three groups each group had 30 patients. Group P received bolus of Phenylephrine 25 microgram, where as group E received Ephedrine 5mg and Group M received Mephentermine 6mg. It was found that rise of blood pressure was significantly higher in case of phenylephrine group in first six minutes, after the bolus, there was significant reduction in the heart rate in phenylephrine group, but there was tachycardia following administration of bolus ephedrine and mephenteramine. Neonatal APGAR score were similar in all three groups. All three drugs maintained hemodynamics within 20 percent of the baseline values on intravenous administration.