Comparison of bolus phenylephrine, Ephedrine and Mephentermine for maintenance of arterial pressure during Spinal anaesthesia in Caesarean section

Abstract

Background: Hemodynamic changes during cesarean delivery after spinal anesthesia are common. The hypotension seen after spinal anesthesia in a cesarean delivery can be treated by many agents. In the management of hypotension during spinal anesthesia for cesarean section, the effects of Phenylephrine, Ephedrine and Mephentermine were compared in this study based on the following parameters-1. The efficacy of the vasopressor in treating hypotension 2. Incidence of undesirable side effects. Materials and method: This study included a total of 120 patients (ASA Grade I and II) undergoing elective cesarean section (with a normal singleton pregnancy, full term/near term) under spinal anesthesia. The patients were randomly allocated into three groups of 40 each. Group ‘P’ was given prophylactic bolus dose of Phenylephrine 100 mcg IV, Group ‘E’ was given prophylactic bolus dose of Ephedrine 10 mg IV and Group ‘M’ received prophylactic bolus dose of Mephentermine 6 mg IV. Blood pressure and heart rate was recorded every 2 minutes for 20 minutes and thereafter every 5 minutes till the end of the surgery. Results: In managing hypotension between the three groups, no difference was found between them. The incidence of bradycardia was higher in the Phenylephrine group. Conclusion: All the three vasopressors are effective (in intravenous form) in maintenance of maternal arterial pressure. Although Phenylephrine has quicker peak effect, in comparison to Ephedrine and Mephentermine and it causes reduction in heart rate.