A comparative study of addition of 1 µg/kg dexmedetomidine or 1 µg/kg fentanyl to 0.75% ropivacaine for transversus abdominis plane block: Evaluation of effects on postoperative pain in abdominal hysterectomies

Background and Aims: Postoperative pain after total abdominal hysterectomy results in multiple complications. The primary objective of this study was to compare the duration of analgesia, and the secondary objectives were to evaluate the total number of rescue analgesics in 24 hours, hemodynamic changes, and adverse effects if any. Methodology: This prospective, randomized, double-blind study was conducted on a total of 100 female patients belonging to American Society of Anaesthesiologists class I and II undergoing abdominal hysterectomies under spinal anesthesia, who were randomly allocated into two groups: Group D (n = 50) received 0.75% ropivacaine 10 ml + 1 μg/kg dexmedetomidine diluted in 10 ml normal saline (NS), and Group F (n = 50) received 0.75% ropivacaine 10 ml + 1 μ g/kg fentanyl diluted in 10 ml NS bilaterally by transversus abdominis plane (TAP) block after completion of surgery. Results: The total duration of analgesia was significantly longer in Group D (634.70 ± 103.88 min) as compared to Group F (512.20 ± 90.52 min) ( P < 0.05). There was a significantly larger amount of rescue analgesic (Inj. Tramadol I.V.) used in Group F (148.00 ± 50.47 mg) as compared to Group D (124.00 ± 43.14 mg) ( P < 0.05). The hemodynamic parameters were comparable in both the groups without any significant adverse effects. Conclusion: Addition of dexmedetomidine with ropivacaine for TAP block is better than addition of fentanyl with ropivacaine in terms of better postoperative analgesia and less rescue analgesic requirement with comparable hemodynamics and side effect profiles.