Comparison of Two Low Dose Regimens of Subarachnoid Block Anesthesia for Lower Segment Caesarian Section

Abstract

Hypotension and bradycardia due to sympathetic blockade are two commonest complications of spinal anesthesia leading to maternal and neonatal morbidity and mortality. Aorto caval compression due to gravid uterus also contributes to the development of hypotension. Wedge under right buttock to provide 250 sideways tilt is used to prevent aortocaval compression by gravid uterus.Low dose bupivacaine heavy with intrathecal fentanyl is recommended as strategy to prevent spinal anesthesia induced hypotension and related complications. The present study was done in our tertiary care centre to compare the effects of fixed dose of Fentanyl 20μg (0.4ml) administered along with two low doses 1.6 ml(8mg) and 1.8 ml(9mg) of 0.5% hyperbaric bupivacaine (heavy) and assess the adequacy of surgical anaesthesia for caesarean section and hemodynamic changes intra operatively. There was faster onset of sensory blockade, better haemodynamic stability and prolonged postoperative analgesia in patients administered with1.6ml of 0.5% Bupivacaine heavy (8mg) & 20μg Fentanyl (Gp I) compared with patients administered with 1.8ml of 0.5% Bupivacaine heavy (9 mg) & 20μg Fentanyl (Gp II) . Perioperative analgesia was excellent in both the groups. No patient who developed bradycardia or hypotension in Gp I and only 2 patients in Gp II developed hypotension.Post-operative analgesia was for a longer period in Group II as compared to Gp I.