Comparison of intravenous bolus phenylephrine, ephedrine and mephentermine for maintenance of arterial blood pressure during spinal anaesthesia in caesarean section

Abstract

Background: Subarachnoid block, although being highly efficient, often has limitation such as hypotension which can result in adverse maternal and fetal outcome, continues to be a matter of concern to the Anesthesiologist. The study was to compare the effect of phenylephrine, ephedrine and mephentermine, for maintenance of arterial pressure during spinal anaesthesia for caesarean section. Methodology: A prospective randomized double blinded study involving 90 patients with hypotension after subarachnoid block under spinal anesthesia was conducted, dividing them into three groups: P (Phenylephrine) 100 mcg, E (Ephedrine) 6 mg, and M (Mephentermine) 6 mg. Patients were compared based on age, weight, height, hemodynamic parameters, complications, and neonatal APGAR scores. Results: On inter-group comparison rise in systolic, diastolic and mean arterial blood pressure at 1,2,4 and 6min after drug administration were significantly high in phenylephrine group (p /= 7 in the three groups at the 1st and 5th min. Conclusion: The study found that phenylephrine, ephedrine, and mephentermine effectively maintained arterial blood pressure in intravenous bolus form during subarachnoid block for caesarean section. Phenylephrine, a fast-acting, short-lived normotensive drug, significantly reduced heart rate compared to ephedrine and mephentermine, but did not cause significant adverse effects on mother and fetus.

Keywords

• hypotension
• ephedrine
• mephentermine
• phenylephrine
• subarachnoid block