A comparative study of low dose Bupivacaine vs high dose Bupivacaine along with Fentanyl and Phenylephrine on Pregnant women undergoing elective Caesarean Section under Spinal Anesthesia

Abstract

Background: This randomized study was conducted to evaluate the effect of low dose vs high dose Bupivacaine+Fentanyl, with or without Phenylephrine infusion on hemodynamics, motor recovery, adequacy of block and side effects, on pregnant women undergoing caesarean section under spinal anaesthesia. Methods: One hundred sixty pregnant women were randomized into four groups of fourty each. Group-A (n=40) received 10 mg(2ml) of Bupivacaine + Fentanyl 25µg(0.5ml) along with Phenylephrine i.v. infusion of 0.25µg/Kg/min. Group-B (n=40) recieved same drugs, without Phenylephrine infusion. Group-C (n=40) received 7 mg(1.4ml) of Bupivacaine+Fentanyl 25µg(0.5ml) along with Phenylephrine i.v. infusion of 0.25µg/Kg/min. Group-D (n=4) received same drugs , without Phenylephrine infusion. Result: When given with fentanyl, low dose bupivacaine (1.4 ml / 7 mg) was as effective as of high dose buypivacaine (2ml/ 10mg) in producing adequate relaxation and analgesia. Addition of low dose phenylephrine infusion decreased the incidence of hypotension maintains the pulse rate nearer to baseline for better hemodynamic stability. The motor recovery was quick in case of low dose bupivacaine groups with or without phenylephrine which aids in early mobilization of pregnant women. Conclusion: When given along with an opioid like fentanyl, low dose bupivacaine (1.4 ml / 7 mg) was as effective as of high dose buypivacaine (2ml/ 10mg) in producing adequate relaxation and analgesia. Addition of low dose phenylephrine infusion decreased the incidence of hypotension and maintained better hemodynamic stability