Interscalene Block Versus Pericapsular Nerve Block and Superficial Cervical Plexus Block for Arthroscopic Shoulder Surgery

Background: Interscalene brachial plexus block (ISB) remains the gold standard for analgesia in arthroscopic shoulder surgery (ASS). However, ISB is associated with a higher incidence of hemidiaphragmatic paralysis (DP). Objectives: This study compares ultrasound-guided interscalene brachial plexus block (USG-ISB) with a combination of ultrasound-guided pericapsular nerve block (USG-PENB) and superficial cervical plexus block (SCPB) to evaluate analgesic efficacy and the incidence of DP. Methods: In this prospective, triple-blinded randomized trial, 42 American Society of Anesthesiologists (ASA) I - II patients undergoing elective ASS were randomized into two groups after induction of general anesthesia (GA): Group A (ISB, 10 mL 0.25% bupivacaine) or group B [pericapsular nerve block (PENB) 10 mL + SCPB 5 mL 0.25% bupivacaine]. Blocks were performed under ultrasound guidance. The primary outcome was the incidence of DP; secondary outcomes included pain scores, opioid consumption, pulmonary function, and patient satisfaction. Results: Compared with group A, group B demonstrated a delayed time to first request for rescue analgesia (13.24 vs. 8.38 hours; P < 0.001) and reduced 24-hour fentanyl consumption (135.71 vs. 192.86 mcg; P = 0.012). Pulmonary function was significantly better preserved in group B (P < 0.05). The incidence of DP was lower in group B (4.76% vs. 38.1%; P = 0.02). Pain scores at 6, 12, and 18 hours were also lower in group B (P < 0.05). Both groups showed no differences in hypotension, bradycardia, or patient satisfaction. Conclusions: The combination of PENB and SCPB provides analgesia non-inferior to ISB, while significantly reducing the incidence of DP and opioid requirements. For individuals at risk of respiratory impairment, this approach presents a lower-risk alternative without compromising pain control efficacy.