Comparison of intravenous bolus doses of phenylephrine vs ephedrine along with crystalloid co-loading in the prevention of hypotension during spinal anesthesia for caesarean section

Abstract

Caesarean section was the first obstetrical operation that saves the life of the baby when normal delivery fails. Spinal anaesthesia is the most appropriate method for caesarean section. But hypotension is the most common side effect of it in patient with pregnant uterus. To compare the vasopressor effects of ephedrine and phenylephrine in ameliorating hypotension in elective caesarean delivery receiving crystalloid coloading, during intrathecal bupivacaine injection.: Study participants were randomly divided into two groups of 50 patients each. After subarachnoid block, all the parturients were given rapid administration of ringer lactate solution 20ml/kg, during the initial 5 minutes of surgery the parameters such as oxygen saturation, blood pressure and pulse rate recorded for every one minute followed by every five minutes until the completion of the surgery. The incidence of hypotension, bradycardia, nausea/vomiting, block height and requirements of vasopressor (ephedrine and phenylephrine) were recorded. Apgar score, and blood sample from umbilical cord was taken and sent for blood gas analyses to determine the neonatal outcome.: Vasopressor consumption was more in phenylephrine group (92±112 µg) compared to ephedrine group (4.8±5.5 mg) which was statistically significant p=0.0001. The neonatal outcome was statistically significant regarding umbilical cord pH (Group E-7.2±0.06 and Group P-7.37±0.04 with p=0.002) but clinically no true fetal acidosis in either groups and no significant changes regarding Apgar score in the two groups.: Thus we conclude that that ephedrine 6 mg and phenylephrine 100 µg does not differ in their efficacy to manage hypotension during spinal anaesthesia for caesarean delivery. However, maternal bradycardia was more in the phenylephrine group with equal incidence of fetal acidosis in the study groups.