Comparision of fixed dose/calculated dose according to height & weight of hyperbaric Bupivacaine for elective cesarean section of parturients in tertiary care hospital

Abstract

Background: Spinal anesthesia is the preferred anesthetic technique for cesarean deliveries. But there is a dosage dilemma regarding block to the desired level and preventing hypotension. We aim to study effects of fixed dose with height and weight adjusted dose of intrathecal 0.5% hyperbaric bupivacaine during elective cesarean section.Methods: Eighty-eight singleton term parturients were enrolled and divided into two groups, Group FD (Fixed Dose) and CD (Calculated Dose) in this prospective, double-blind, randomized controlled trial. Group FD received 2.0 ml and CD received a height and weight adjusted calculated dose based on Harten's chart. Hemodynamic changes, onset time to sensory block to T6, maximum block in 20 minutes, and adverse effects were compared.Results: There was a significant reduction in median drug dosage of 10 mg in FD versus 8 mg in CD group. The mean onset time of spinal block to T6 in group FD of 2 minutes was faster than Group CD 4 minutes. The spinal block extended above T4 in the larger number of parturients 23 (52%) in Group FD than in three (6.8%) in group CD (p<0.05). Significantly larger number 20 (45.45%) in group FD developed hypotension than seven (15.9%) in Group CD. Bradycardia and vomiting were also found in group FD. Conclusions: The calculated dose provided the desired level of the spinal block and also restricted spinal block level with a distinct advantage of less hypotension.