Ultrasound-guided Retrolaminar Block Versus Intraperitoneal Block for Postoperative Analgesia of Adult Patients Undergoing Laparoscopic Cholecystectomy: Randomized, Controlled Trial

A high-frequency 12 MHz linear ultrasound probe will be used, patients will receive bilateral ultrasound-guided retrolaminar plane block with 20 mL of bupivacaine 0.25%. Their spines will be palpated from the vertebra prominens caudally to T7 and point will be marked to identify the spinous processes, which will be confirmed by ultrasound through counting from T12 with the characteristic last rib attached to its transverse process upward to the T7 lamina. The linear high frequency transducer (6-13 MHz) will be placed in the parasagittal plane one cm lateral to the midline. The needle will be inserted in the in-plane view of the ultrasound probe and will be advanced from downward to upward to target the T7 posterior lamina surface at an angle of 90˚ to the skin until the needle tip will be contacted the posterior surface of targeted lamina . After negative aspiration, 20 mL of bupivacaine 0.25% will be injected. The procedure was repeated following the same steps on the other side.

before giving an incision for the ports, 20 ml of 0.25% bupivacaine will be infiltrated subcutaneously over the port sites (6 ml will be infiltrated around each midline port site and 4 ml will be infiltrated around at the lateral port sites) and at the end of surgery and before the removal of trocars, 20 ml of 0.25% bupivacaine diluted in normal saline will be instilled by the surgeon intraperitoneally at gallbladder bed and under domes of both diaphragms under direct vision with a separate catheter passed through one of the trocars.. The pressure of the gas insufflation was kept within 10-12 mm Hg in all patients. At the end of surgery, CO2 was evacuated, and intraperitoneal anesthetic solution was left in situ.