Evaluation of the role of dexmedetomidine in improvement of the analgesic profile of thoracic paravertebral block in thoracic surgeries: A randomised prospective clinical trial

Background and Aims Thoracic paravertebral block (TPB) is one of the effective methods for management of post-operative pain in thoracic surgeries. The aim of the study was to evaluate effectiveness of addition of dexmedetomidine to paravertebral block with bupivacaine in improving the postoperative pain relief and pulmonary functions in patients undergoing thoracic surgeries. Methods A prospective randomized double-blinded study was performed on forty patients scheduled for thoracic surgery. A paravertebral catheter was secured under ultrasound guidance preoperatively for all patients. Group B (n = 20) received a bolus dose of 0.25% bupivacaine at 0.3 mL/kg followed by continuous infusion of 0.125% bupivacaine 0.1 mL/kg/h. Group (BD) received a bolus dose of 0.25% bupivacaine + dexmedetomidine 1 μg/kg at 0.3 mL/kg followed by continuous infusion of dexmedetomidine 0.2 μg/kg/h + 0.125% bupivacaine 0.1 mL/kg/h. Anaesthesia technique was standardized for all patients. Postoperatively, all patients were assessed during first 24 hours for intraoperative fentanyl and post-operative morphine requirements, Visual Analogue Scores (VAS) scores at rest and during cough, and postoperative pulmonary functions. Results Post-operative morphine consumption in the first 24 hours and intraoperative fentanyl requirement were significantly less in group BD (2.95 ± 1.986 mg, 80.75 ± 31.551μg respectively) compared to group B (9.85 ± 3.468 mg, 186 ± 39.683 μg respectively). Group BD showed less VAS scores during cough and better postoperative pulmonary functions (P < 0.05). Conclusion Addition of dexmedetomidine to paravertebral bupivacaine in patients undergoing thoracic surgeries provides more effective analgesia with improvement in post-operative pulmonary functions.