A comparative study of bolus phenylephrine and mephentermine for treatment of hypotension during spinal anaesthesia for caesarean section

Abstract

Background: Spinal anesthesia for caesarean section has several advantages over general anaesthesia like decreased risk of failed intubation, decreased risk of pulmonary aspiration of gastric contents, avoidance of the depressant effects of general anesthetics on neonate etc.Aim and Objectives: This comparative study was designed to evaluate the efficacy of Mephentermine and Phenylephrine in treating hypotension during spinal anaesthesia for cesarean section. The incidence of undesirable side effects like maternal bradycardia, nausea and vomiting also noted.Methodology: The study was conducted in the Department of OBG the Maternity Hospital, Osmania Medical College during the year August 2018- November 2019.The study includes 60 patients grouped into two groups.Results: Both Phenylephrine and Mephentermine maintained the arterial pressure effectively within 20% of baseline values. The mean value of heart rate was high in Mephentermine group compared with Phenylephrine group. The mean values of Systolic BP, Diastolic BP and MAP were higher in Phenylephrine group compared with Mephentermine group throughout the study period. Phenylephrine group required fewer number of bolus doses when compared with Mephentermine. The heart rate generally remained low throughout the study period in Phenylephrine group and the incidence of bradycardia was more in Phenylephrine group when compared with Mephentermine group. The occurrence of nausea and vomiting were similar in both groups.Conclusion: Thus, it can probably enhance organ blood flow more than mephentermine. Mephentermine increases heart rate and thus may be avoided in population where the effect may be detrimental.