Comparison of efficacy of modified thoracoabdominal nerve block through perichondrial approach (M-TAPA) vs Oblique subcostal transverse abdominis plane block (OSTAP) for postoperative pain relief in patients undergoing laparoscopic cholecystectomy.

This prospective randomised study will be conducted in 50 patients aged 18-65 years, either gender, ASA I-II undergoing elective laparoscopic cholecystectomy after obtaining institutional ethics committee approval,  CTRI registration and patients written informed consent. Patientrefusal of consent, coagulation disorder, infection at the injection site of the block, known allergy to local anaesthetics, chronic hepatic or renal failure, history of abdominal surgery or trauma, conversion of laparoscopic to open surgery, consumption of any pain killers within the 24 h before the operation, chronic opioid consumption, pregnancy, alcohol or drug abuse and body mass index (BMI) ≥ 35 kg m-2will be excluded. The aim of the study is to compare the efficacy of MTAPA with OSTAP block for postoperative pain relief. The primary objective is to compare the effect of M-TAPA with OSTAP blocks on post-operative rescue analgesic consumption in the first 24 hours. The secondary objectives are to assess postoperative pain evaluation using Numeric Rating Scale (NRS) at 0 min, 30 min, 60 min, 2 hrs, 4 hrs, 6 hrs, 12 hrs and 24 hrs postoperatively and at the time of rescue analgesic request, time to first rescue analgesic administration, number of thoracoabdominal dermatomes anaesthetised at 2 hrs after surgery and Adverse effects (if any). Patients will be randomized into 2 groups : Group O and Group M. Group O will be given OSTAP block bilaterally after induction of anaesthesia. Group M will be given MTAPA block bilaterally after induction of anaesthesia. Demographic data, evaluation of pain using NRS scale, time to first rescue analgesic, total rescue analgesic consumption, number of thoracoabdominal dermatomes anaesthetized and adverse effect, if any will be observed.