Diaphragmatic function sparing of regional analgesia in shoulder arthroscopy: interscalene versus anterior suprascapular nerve block

Background Effective pain management in shoulder arthroscopy is crucial for patient comfort, early mobilization, and prevention of chronic pain. Interscalene plexus block (ISB) provides excellent analgesia but is associated with adverse effects, including diaphragmatic paralysis. This study aimed to compare the efficacy and safety of ISB and anterior suprascapular nerve block (SSB) for postoperative analgesia in shoulder arthroscopy.The Aim of the Work To assess the comparative efficacy of ISB and anterior SSB in terms of pain relief, hand grip strength, respiratory outcomes, and incidence of complications in patients undergoing shoulder arthroscopy.Patients and Methods A total of 44 patients were randomized into two groups: Group I (ISB) and Group II (SSB). Pain intensity was measured using the Visual Analog Scale at multiple postoperative intervals, specifically every 1 hour for the first 4 hours, then every 4 hours for the next 24 hours. Pulmonary function using spirometry and Diaphragmatic excursion assessed by ultrasound were both evaluated before the block (baseline), 30 minutes after the block, and 2 hours after extubation. Hand grip strength was measured preoperatively and again 2 hours after surgery Complications and side effects were documented throughout the postoperative period.Results Both ISB and SSB provided comparable VAS scores and duration of analgesia between groups. However, the ISB group showed a significant reduction in FVC and FEV1 by over 50% with significant decrease in diaphragmatic function compared to minimal reductions in the SSB group. ISB resulted in greater impairment of hand grip strength and a higher incidence of transient phrenic nerve palsy.Conclusions Both ISB and SSB are effective for postoperative pain management in shoulder arthroscopy. SSB offers a superior safety profile, and may be preferable, especially for patients with preexisting respiratory conditions.