Effect of Dexmedetomidine as an Adjuvant to Bupivacaine in Ultrasound-Guided Erector Spinae Plane Block for Cesarean Section - A Randomized Controlled Trial.

PURPOSE: This study aims to compare the efficacy of erector spinae plane (ESP) block with plain bupivacaine versus erector spinae plane block with bupivacaine supplemented with dexmedetomidine in patients scheduled for cesarean section. DESIGN: A randomized controlled trial involving 50 patients posted for elective lower segment cesarean section METHODS: Study participants were randomly assigned to receive bilateral ultrasound ‑ guided ESP block with 20 ml 0.25% bupivacaine alone (Group A, n = 25) or 20 ml of 0.25% bupivacaine with 0.5mcg/kg dexmedetomidine (Group B, n = 25) postoperatively. The primary outcome was total analgesic consumption in the first 24 h after surgery and the secondary outcomes were time for the first request to analgesia, duration of block, visual analog scale (VAS) in 48 h and incidence of adverse effects. Statistical analysis was done using IBM SPSS Statistics-23. Data were compared using the Kolmogorov-Smirnov Test and the Shapiro-Wilk Test, Chi‑square test, independent t‑test and Mann Whitney U test. FINDINGS: The total number of analgesic doses (3.3 vs 2.1, mean difference CI 0.71 to 1.16; p=0.001), the total paracetamol required (2.0 vs 1.1 g, mean difference CI 0.53 to 1.22; p=0.001), and the total tramadol required (64 vs 50 mg, mean difference CI 4.79 to 23.20; p=0.004) were all lower in Group B, with statistically significant differences observed between groups. The time to first request for analgesia (8.3 h vs 12.6 h, with a mean difference in confidence interval -6.18 to 2.39, p=0.001) and the duration of block (10.95 h vs 16.47 h, with a mean difference in confidence interval -7.22 to 3.81, p=0.001) were both longer in Group B compared to Group A. The VAS score in Group B was lower and reached statistical significance at 2 h (p=0.001) and 12 h (p=0.048). The incidence of bradycardia was higher in Group B (p=0.01). CONCLUSION: Dexmedetomidine is an effective adjuvant to bupivacaine in ESP block for reducing total postoperative analgesia requirement and improving efficacy and duration of block in cesarean section.