A study to compare two ultrasound-guided nerve block techniques for pain relief after laparoscopic gallbladder surgery

INTERVENTION: Intervention1: Ultrasound‐guided bilateral External Oblique Intercostal Plane Block: Ultrasound‐guided bilateral external oblique intercostal plane block will be performed after induction of general anaesthesia and tracheal intubation. Under strict aseptic precautions, a high‐frequency linear ultrasound probe, 5 12 MHz, will be placed in the parasagittal plane between the midclavicular and anterior axillary line at the level of the 6th 7th ribs. A 22‐G, 10‐cm needle will be advanced using an in‐plane technique, and 20 mL of 0.25% bupivacaine will be injected on each side into the fascial plane between the external oblique and intercostal muscles. Control Intervention1: Ultrasound‐guided bilateral Subcostal Transversus Abdominis Plane Block: Ultrasound‐guided bilateral subcostal transversus abdominis plane block will be performed after induction of general anaesthesia and tracheal intubation. Under strict aseptic precautions, a high‐frequency linear ultrasound probe, 5‐12MHz, will be placed obliquely along the subcostal border close to the xiphisternum. The transversus abdominis muscle will be identified by seeing it posterior to the rectus muscle. A needle will be inserted using an in‐plane approach, and 20 mL of 0.25% bupivacaine will be injected on each side into the fascial plane between the rectus abdominis and transversus abdominis muscles. CONDITION: Health Condition 1: O‐ Medical and Surgical PRIMARY OUTCOME: Total postoperative rescue analgesic consumption following laparoscopic cholecystectomy.Timepoint: First 24 hours postoperatively. SECONDARY OUTCOME: Number of thoracoabdominal dermatomes anaesthetised.Timepoint: 2 hours postoperatively. Postoperative pain intensity measured using the Numeric Rating Scale at rest and on movement.Timepoint: At 0 minutes, 30 minutes, 60 minutes, 2 hours, 4 hours, 6 hours, 12 hours and 24 hours postoperatively, and at the time of first rescue analgesic request. Time to first rescue analgesic administration.Timepoint: Within 24 hours postoperatively. INCLUSION CRITERIA: 1.Scheduled for elective laparoscopic cholecystectomy under general anaesthesia. 2. American Society of Anesthesiologists,ASA, physical status I or II. 3. Willing to participate in the study and provide written informed consent.