“Comparative evaluation of dexmedetomidine and dexamethasone as adjuvant with bupivacaine in ultrasound guided tap block for post operative pain relief in patients undergoing laparoscopic cholecystectomy”

Background: Many adjuvants have been used to increase the duration and quality of local anaesthetics in different nerve block techniques. Aim of this study was to evaluate the relative efficacy of bupivacaine and dexmedetomidine versus bupivacaine and dexamethasone for post-operative analgesia using ultrasound-guided TAP block in laparoscopic cholecystectomies.
Objective-The primary objective was to compare quality of analgesia using Visual Analog Scale (VAS), duration of postoperative analgesia, whereas the secondary objective was to assess the requirement of rescue analgesia and reduction in 24 hour intra venous PCM/NASAID consumption, to compare hemodynamic parameters (heart rate, MAP, SPO2, and respiratory rate) and to measure adverse effect if any.
Methods: A prospective randomised controlled clinical study was conducted in 60 patients undergoing laparoscopic cholecystectomies. Participants were divided into two groups in which group 1 (DM) received 20 ml of 0.25% bupivacaine hydrochloride with 8 mg dexamethasone as TAP block and those in a group 2 (DA) received 20 ml of 0.25% bupivacaine hydrochloride with dexmedetomidine 1ug/kg as TAP block at the end of surgery. Postoperative pain was evaluated by Visual Analog Score for pain scoring at 0 min,30 min, 1 hr, 2 hr, 4 hr , 6 hr, 12 hr, 18 hr, and 24 hr postoperatively. Subjective assessment of duration of analgesia was done.
Results: Patients receiving USG guided TAP block with bupivacaine with dexmedetomidine as adjuvant (group 2) had significantly lower pain score when compared to patients with bupivacaine with dexamethasone as adjuvant(group1) at the postoperative 0 min (4.83vs 3.43, p=0.008), 15 min (5.30 vs 3.80, p=0.002), 30 min (5.27 vs 3.87, p=0.002), 1 hour (4.67 vs 3.87, p=0.34), 2 hour ( 4.53 vs 3.33, p=0.002), 4 hour (4.37 vs 2.67, p=<0.001), 6 hour (3.97 vs 2.70, p=0.002), 12 hour ( 3.80 vs2.83, p=<0.001 ), and 18 hour (3.37 vs 2.67, p=0.011). Requirement of first dose of rescue analgesia among patients of dexamethasone group was significantly earlier as compared to dexmedetomidine group (108.00 vs 422.00 min p=<0.001). Total dose of rescue analgesia used (gram of paracetamol iv) was less in dexmedetomidine group as compared to dexamethasone group (p=30 vs 16, p=0.13). No complications related to nerve block were observed.
Conclusion: Dexmedetomidine added to bupivacaine for TAP block in laparoscopic cholecystectomy prolongs the duration of postoperative analgesia, have lower Visual analogue score and less rescue analgesia requirement than dexamethasone added to bupivacaine.