A Prospective Randomized Interventional Study to Determine the Influence of Spinal Flexion Versus Extension in the Lateral Decubitus Position on the Unilaterality of Spinal Anesthesia Using Hyperbaric Bupivacaine for Elective Unilateral Lower Limb Surgeries

Abstract

Objective: A restricted sympathetic block during spinal anesthesia may minimize hemodynamic changes and advantageous in view of maintaining stable cardiovascular profile through intraoperative period. Methods: This prospective randomized interventional study was conducted on a total of 150 patients of either sex aged 20-50 years of American Society of Anesthesiologists grades 1 and 2 were randomly allocated in two groups (75 in each group).Using a 25-gauge Quincke spinal needle, 7.5 mg of 0.5% hyperbaric bupivacaine was injected over a period of 80s at L3-L4 interspace in both groups. Patients were kept in flexion or extension according to belonging groups: Group A (flexion) or Group B (extension) after drug administration for15 min of lateral decubitus position, then patients were turned to supine position. Results: Strict unilateral sensory and motor block at 15 min was noted in Group A 45 patients (60%) and 25 patients (33.33%) in Group B (p=0.002*). At 60 min, there was no significant sensory unilaterality between the groups (p=0.987). At 60 min, 30 patients (40%) in Group A and 14 patients (18.66%) in Group B had strict unilateral motor block (p=0.007*). Highest achieved sensory level on nondependent side was T10 in Group A and T8 in Group B, whereas it was T6 in Group A and T5 in Group B on dependent side. Conclusion: For unilateral spinal anesthesia, spinal flexion position provided better strict unilaterality and restricted sympathetic blockade than spinal extension position.