Efficacy of Ultrasound Guided Transverse Abdominis Plane Block for Postoperative Analgesia in Laparoscopic Cholecystectomy, a Prospective Randomised Controlled Trial

Background and Aims: Ultrasound Guided (USG) Transverse Abdominis Plane (TAP) block is a relatively new regional analgesic technique for postoperative pain relief after abdominal surgery. However, the efficacy and safety of TAP block after laparoscopic cholecystectomy is not well established. This prospective, randomized, controlled, double blind study was designed to compare analgesic efficacy of USG guided TAP block over conventional analgesics in patients undergoing laparoscopic surgery during post-operative period. Methods: One hundred American Society of Anesthesiologists (ASA) physical status I and II patients undergoing laparoscopic cholecystectomy were randomised into two groups. Patients in Group A (n = 50) received standard analgesics along with USG guided TAP block after induction of anaesthesia while patients in Group B (n = 50) received only standard analgesics postoperatively as per standard protocols of the institution. USG guided TAP block was given using high frequency linear probe (6-13 MHz) with 'in-plane' technique. Once the tip of the needle was confirmed in the facial plane between the Internal Oblique muscle and Transverse Abdominis muscle, Injection Ropivacaine 0.25%, 30 ml was administered bilaterally. Each patient was monitored in Post Anaesthesia Care Unit (PACU). Time duration for demanding first dose of opioid, total dose of opioid used, opioid induced and TAP block technique related complications, hospital stay, Visual Analogue Scale (VAS) scores on rest and coughing at 0.5, 1, 2, 4, 6, 12, 24 hours were recorded in each patient. At the end of study data was analysed using appropriate statistical tests and value of p<0.05 was considered significant. Results: Group A patients had a lesser demand of opioid (mean ± SD) 2.44 ± 2.44 mg as compared to patients in Group B (3.96 ± 2.56 mg)(P<0.01). VAS scores at rest and coughing were (mean ± SE) 1.21 ± 0.07 and 1.43 ± 0.01 in group A and 1.72 ± 0.09 and 2.18 ± 0.18 in Group B (P<0.01). There was no difference in time duration for demanding first dose of opioid by patient postoperatively, hospital stay, and opioid related complications in both groups. There was no TAP block technique related complication seen during study. Patients had better analgesic satisfaction after TAP block. Conclusion: USG guided TAP block is a safe and effective mode of postoperative analgesia in 24 hours after laparoscopic cholecystectomy.