Comparison of dexamethasone versus dexmedetomidine as an adjuvant to 0.25% bupivacaine in ultrasound-guided transversus abdominis plane block on postoperative analgesia duration in patients undergoing laparotomy.

Abstract

Objective: To compare the efficacy of dexamethasone and dexmedetomidine as adjuvants to bupivacaine in TAP block in patients receiving laparotomy. Study Design: Prospective Comparative study. Setting: Department of Anaesthesia, Sahiwal Teaching Hospital, Sahiwal. Period: 2^nd October 2025 to 2^nd March 2026. Methods:
Ninety-six patients undergoing laparotomy were equally distributed into two groups. Group A were treated with 0.25% bupivacaine with dexamethasone (8 mg), while Group B received 0.25% bupivacaine with dexmedetomidine (1 µg/kg) in ultrasound-guided TAP block. Postoperative pain was determined using Visual Analogue Scale (VAS) at different timepoint from 0 to 24 hours. Additional parameters such as first rescue analgesia timepoint, total analgesic intake, and hemodynamic parameters were also recorded. Results: Baseline characteristics were comparable and difference were statistically insignificant. However, intensity of pain reduced significantly in Group B patients from 2 to 24 hours (p < 0.05). Participants in Group B required survived longer without the need of first rescue analgesia (11.4 ± 2.1 vs. 6.9 ± 1.5 hours; p < 0.001), and total ketorolac use was lower (51.3 ± 15.6 mg vs. 79.6 ± 18.2 mg; p < 0.001). Similarly, other evaluated postoperative parameters such as mean arterial pressure, heart rate, nausea and vomiting scores were also significantly lower in Group B (p < 0.05). Conclusion: Dexmedetomidine is a more effective adjuvant than dexamethasone in TAP block, providing prolonged analgesia and reduced analgesic requirements after laparotomy.