Comparative Effects of ESP Block and EOIP Block on Postoperative Respiratory Recovery Following Liver Resection

Bilateral ESP block * after induction of general anesthesia and before surgical incision. * T7 or T8 transverse process, selected consistently by protocol. * high-frequency linear probe when feasible; curvilinear probe in larger habitus. In-plane cranial-to-caudal or caudal-to-cranial approach to the fascial plane deep to erector spinae muscle and superficial to the transverse process. * Injectate: 20 mL of 0.25% bupivacaine per side after negative aspiration; hydrodissection used to confirm correct plane. Bilateral EOIP block * after induction of general anesthesia and before surgical incision. * ultrasound-guided injection into the fascial plane between the external oblique muscle and the intercostal muscle/external intercostal membrane near the 6th-8th intercostal spaces on each side, following the institutional standardized approach. * Injectate: 20 mL of 0.25% bupivacaine per side Safter negative aspiration.

An ultrasound-guided bilateral ESP block will be performed after induction of general anaesthesia and before surgical incision. The block will be administered at the T7 or T8 transverse process using an in-plane ultrasound-guided approach. Twenty millilitres of 0.25% bupivacaine will be injected on each side into the fascial plane deep to the erector spinae muscle and superficial to the transverse process after negative aspiration. Correct spread of local anaesthetic will be confirmed by hydrodissection.