Comparing the effectiveness of ropivacaine 0.5% versus ropivacaine 0.2% for transabdominis plane block in providing postoperative analgesia after appendectomy

ObjectiveThe basis for the transversus abdominis plane (TAP) block involves infiltration of a local anesthetic into the neurofascial plane between the internal oblique and the transversus abdominis muscles, causing a regional block that spreads between the L1 and T10 dermatomes. Thus, the TAP block is said to be suitable for lower abdominal surgery. This study was designed to compare the analgesic efficacy of two different concentrations of ropivacaine for TAP block in patients undergoing appendectomy.MethodsFifty-six patients with American Society of Anesthesiologists physical status I or II, aged 18 years and above, undergoing appendectomy were recruited in this prospective, randomized, double-blind study. They were divided into two groups: Group A patients who received 0.5 mL/kg of ropivacaine 0.5% and Group B patients who received 0.5 mL/kg of ropivacaine 0.2% via TAP block under ultrasound guidance. Postoperative pain was assessed using the visual analog scale upon arrival at the recovery room in the operating theatre, just prior to being discharged to the ward, and at 6 hours, 12 hours, 18 hours, and 24 hours postoperatively to compare the effectiveness of analgesia.ResultsIntraoperatively, patients in Group B required a significantly greater amount of additional intravenous fentanyl than those in Group A. There were no significant statistical differences in pain scores at rest and on movement at all assessment times as well as in the dose of 24-hour intravenous morphine consumption given via patient-controlled analgesia postoperatively between the two groups.ConclusionThe effectiveness of two different concentrations of ropivacaine (0.5% versus 0.2%) given via TAP block was comparable in providing postoperative analgesia for patients undergoing appendectomy.