Comparison of Segmental Thoracic and Lumbar Subarachnoid Block in Preeclamptic Patients Undergoing Cesarean Section: An Open-Label Randomized Trial.

Background Preeclampsia is a serious hypertensive disorder of pregnancy characterized by multi-organ dysfunction and often necessitates cesarean delivery. While spinal anesthesia is preferred for cesarean sections, lumbar subarachnoid block may result in significant hypotension due to extensive sympathetic blockade. Thoracic spinal anesthesia has emerged as a potential alternative with better hemodynamic control. Objective To compare the efficacy, safety, and hemodynamic effects of thoracic versus lumbar subarachnoid block in preeclamptic patients undergoing cesarean delivery. Methods In this prospective, open-label, randomized controlled trial, 160 preeclamptic patients scheduled for urgent cesarean sections were allocated to receive either thoracic spinal anesthesia (1.5 mL 0.5% bupivacaine heavy + 25 μg fentanyl) or lumbar spinal anesthesia (2 mL 0.5% bupivacaine heavy + 25 μg fentanyl). The primary outcome was hemodynamic stability; secondary outcomes included surgical anesthesia success, block onset and duration, adverse events, neonatal outcomes, and patient satisfaction. Data were analyzed using appropriate statistical tests, with p<0.05 considered significant. Results Hemodynamic stability was superior in the thoracic group, with a lower incidence of hypotension (11.68% vs. 26.31%, p=0.038) and significantly reduced mean vasopressor (ephedrine) requirement (8.57 ± 1.32 mg vs. 14.41 ± 2.62 mg, p < 0.001). Surgical anesthesia success rates were similar in both groups (thoracic: 96.67%, lumbar: 95%, p=1.0). Thoracic spinal anesthesia was associated with shorter sensory (132.61 ± 13.81 vs. 148.48 ± 14.52 min, p=0.001) and motor block durations (102.23 ± 11.13 vs. 124.01 ± 11.01 min, p=0.001), less shivering and nausea, and greater patient satisfaction. Neonatal Apgar scores and 6-week outcomes were comparable between groups (p>0.05). Conclusion Thoracic spinal anesthesia provides superior hemodynamic stability and better patient comfort with comparable surgical efficacy and neonatal safety, making it a viable option for cesarean delivery in preeclamptic patients when administered by experienced clinicians.