A Comparative Study of Phenylephrine, Ephedrine and Mephentermine for Maintainance of Arterial Pressure during Spinal Anaesthesia in Caesarean Section

Abstract

Hypotension following spinal anaesthesia for Caesarean section is the commonest serious problem encountered by anaesthesiologists. Numerous methods have been tried to minimize hypotension which include fluid preloading, left uterine displacement and use of vasopressor drugs. This study was aimed at comparing the efficacy of three drugs Phenylephrine, Ephedrine and Mephentermine for maintenance of arterial blood pressure during spinal anaesthesia in caesarean section. 60 patients between the age group of 18-35 years undergoing elective as well as emergency caesarean section under spinal anaesthesia who developed hypotension after subarachnoid block(SAB) were selected and randomly allocated into 3 groups of 20 each to receive Group P -Phenylephrine 50mcg, Group E - Ephedrine 6 mg, and Group M -Mephentermine 6 mg as bolus IV and repeated as required. Comparability of groups were analysed with Analysis of Variance (ANOVA) test. All the 3 drugs effectively controlled SBP & DBP. On intergroup comparision rise of SBP and DBP in phenylephrine group was more than in other two groups. Tachycardia was significantly less in Group P after administration of the study drug. Phenylephrine causes reduction in heart rate, which may be advantageous in cardiac patients and patients in whom tachycardia is undesirable.