COMPARATIVE EVALUATION OF PROPHYLACTIC INTRAMUSCULAR PHENYLEPHRINE AND EPHEDRINE ON SPINAL ANAESTHESIA INDUCED HYPOTENSION DURING CAESAREAN SECTION AND THEIR EFFECTS ON APGAR SCORE AND NEONATAL OUTCOMES

The incidence of hypotension during spinal anaesthesia for caesarean section is reported to be as high as 80% and effects neonatal outcome. Ephedrine, unlike phenylephrine, has a dose-related propensity to depress fetal pH during spinal anesthesia during cesarean section. A low arterial umbilical cord pH has a strong association with neonatal mortality and morbidity. Randomized prospective clinical trial was done to evaluate the efficacy of intramuscular ephedrine and phenylephrine administered 10 minutes before the induction of spinal anaesthesia in preventing hypotension following spinal anaesthesia for caesarean section. We evaluated the impact of vasopressor change on Apgar scores (1 and 5 min), incidence of Apgar score <7(1 and 5 min) in low-risk elective cesarean sections Patients and methods: Two hundred ASA Grade I and Grade II parturients scheduled for undergoing elective caesarean section under spinal anaesthesia were divided into four groups to receive intramuscular ephedrine or phenylephrine or equal volume of saline, 10 minutes before induction of spinal anaesthesia. Results: Incidence of hypotension was significantly less in phenylephrine 4mg group (32%) and ephedrine 45mg group (42%) compared to phenylephrine 2mg group (70%) and control group (86%). They also had a lower total dose of rescue IV ephedrine i.e 20 doses and 25 doses compared with phenylephrine 2mg group i.e 61 doses and controls i.e 80 doses. Conclusion: prophylactic intramuscular bolus of phenylephrine 4mg and ephedrine 45mg reduced the severity and incidence of hypotension and the total dose rescue IV ephedrine during spinal anaesthesia for caesarean section and have no impact on neonatal venous pH & outcome.