Rhomboid Intercostal Block with Subserratus Plane Block in Bariatric Surgery

Immediately post-surgery, patients in the PCA group received a programmed PCA infusion (YG-B-3; Jiangsu Yaguang Medical Device Co., Ltd., China) containing either ketorolac (180 mg) or sufentanil (200 µg) in 100 mL, delivered as a 2 mL/h basal infusion with 0.5 mL boluses; lockout interval: 15 min.

Following epidural catheter placement in the operating room, the CEA group received an initial bolus of 2% lidocaine (3 mL). Once sensory blockade was confirmed, continuous epidural infusion of 0.1% ropivacaine (8 mL/h) commenced.

RISS blocks were performed at the T4-T10 level under ultrasound guidance (EPIQ5 with L12-4 linear 7.5 MHz transducer; Philips Healthcare, Best, Netherlands). A 19-gauge, 40-cm catheter was advanced 3-5 cm beyond the needle tip into the subserratus plane, its position confirmed by injecting 5 mL of 0.2% ropivacaine. A further 15 mL of 0.2% ropivacaine was then administered. The catheter was connected to a PCA pump programmed to deliver a 7 mL/h basal infusion with 2 mL boluses; lockout interval: 30 min.