Fixed Dose Versus Height and Weight Adjusted Dose of Bupivacaine for Spinal Anesthesia in Elective Caesarean Section

Background: Spinal anesthesia is gaining global popularity. Caesarian section with spinal anesthesia are considered one of the comment applied surgeries. Hypotension is one of most frequent side effect of spinal anesthesia, if uncorrected causes adverse effect on the mother and neonate . The aim of this study is to assess the hemodynamic measures and anesthetic outcome between fixed dose and adjusted for weight and height dose of bupivacaine. Patients and method: A comparative clinical trial double-blinded study was conducted in the operation theatre of the obstetric surgical department, Baghdad Teaching Hospital, Baghdad, Iraq during the period from the 1st of April 2022 to the 1st of July 2023. A total of 100 pregnant women were included in this study who underwent cesarean section under spinal anesthesia and met the inclusion criteria. These women were allocated randomly into two groups: Group A: Fixed dose group: 50 patients received an intrathecal dose of heavy bupivacaine (0.5%) 2.5 ml. Group B: adjusted dose group: 50 patients received intrathecal adjusted dose heavy bupivacaine (0.5% ) according to height and weight of patient from Hartens chart. Results: A higher mean SBP was reported among the adjusted dose group at 15 min., 20 min., 30 min., and 40 min. (P=0.002, 0.002, <0.001, and <0.001 respectively). A higher mean DBP was reported among the adjusted dose group at 10 min., and 20 min. (P=0.037, and 0.005 respectively). A higher mean MBP was reported among the adjusted dose group at 30 min., and 40 min. (P=0.001, and <0.001 respectively). A lower mean HR due to bradycardia among some cases was reported among the fixed-dose group at 10 min., 30 min., and 40 min. (P=0.024, 0.034, and <0.001 respectively) lowest 10 min., 30 min., and 40 min. (P=0.024, 0.034, and <0.001 respectively). There 40.0% (20) patients in the fixed-dose group received an ephedrine dose once and 24.0% (12) patients in the fixed-dose group received an ephedrine dose more than once, and this was significantly higher than the adjusted dose (P=0.027). Conclusion: Adjusting bupivacaine dose in spinal anesthesia for elective cesarean sections provides favorable hemodynamic stability with adequate anesthetic outcome in both groups