Prophylactic Infusions of Phenylephrine and Ephedrine during Combined Spinal Epidural Anaesthesia for Caesarean Section: A Comparative Study

Abstract

Background: Hypotension is the most common adverse effect in parturients after spinal anaesthesia for Caesarean section. Despite various pharmacological and non-pharmacological methods used in its prevention and treatment, vasopressors have become very important in the management of this form of hypotension.Objective: This study was aimed at comparing the efficacy and safety of prophylactic intravenous infusions of phenylephrine and ephedrine at preventing maternal hypotension during Combined Spinal Epidural anaesthesia (CSE) for Caesarean section.Methods: Sixty ASA I and II patients scheduled for elective Caesarean section, were randomly allocated into two groups. Patients in Group I received Phenylephrine 80 μg/min while patients in Group II received Ephedrine 1 mg/min immediately after the subarachnoid 10 mg plain bupivacaine injection while the epidural catheter was being inserted and secured. All the patients received a crystalloid preload of 1 litre of 0.9% normal saline prior to the induction of CSE. Results:The overall incidence of hypotension was 8.5% (6.7% in the phenylephrine group and 10.3% in the ephedrine groups). The lowest systolic (105.8 ± 9.2 mmHg) and diastolic arterial pressures (60.9 ± 8.9 mmHg) occurred in the ephedrine group while the lowest heart rates occurred in the phenylephrine group. The mean umbilical artery pH was 7.3 while Apgar scores at 1 st and 5 th min were essentially the same in the two groups. Conclusion:Prophylactic intravenous infusions of phenylephrine and ephedrine are safe and effective at reducing the incidence and severity of hypotension during combined spinal epidural anaesthesia for elective Caesarean section with no associated neonatal acidosis.