Effects of the interscalene block on opioid use and hospital stay in shoulder surgery

Abstract

Background & objective: Regional anesthesia techniques have increasingly been used around the globe, either as a stand-alone technique or as a part of balanced anesthesia. This study aimed to evaluate the effect of interscalene block (ISB) on postoperative hospital length of stay (LOS), opioid consumption, and inflammatory markers in patients undergoing elective shoulder surgery under general anesthesia (GA). The goal was to determine whether this regional anesthesia technique contributes to improved postoperative outcomes under GA. Methodology: This single-center, retrospective study included 276 patients who underwent elective shoulder surgery between January 2018 and December 2022 under general anesthesia. Patients were divided into two groups based on whether they received an interscalene block or not. Exclusion criteria included patients younger than 18 years, and older than 80 years, ASA class IV or higher, emergency surgery, missing laboratory data, and use of other regional anesthesia methods. Data on opioid consumption, hospital stay, and inflammatory markers, including white blood cells (WBC) and C-reactive protein (CRP), were compared using Mann-Whitney U, chi-square, and Friedman tests. P < 0.05 was considered statistically significant. Results: Postoperative opioid use was significantly lower in the block group, with 60.7% requiring no opioids versus 0.8% in the non-block group (P < 0.05). The median hospital length of stay was significantly shorter in the ISB group (22.0 hours) compared to the non-ISB group (29.3 hours, P = 0.01). Median postoperative WBC levels at 24 hours were significantly lower in the ISB group compared to the non-ISB group (8.50 x 103/mu L vs. 9.50 x 103/mu L, P < 0.05). Similarly, CRP levels at 6 and 24 hours showed statistically significant differences between groups; however, the direction of these differences varied and should be interpreted with caution. Conclusion: Interscalene block reduces postoperative opioid consumption, shortens hospital stay, and mitigates systemic inflammation in shoulder surgery performed under general anesthesia. It may be a valuable component of multimodal analgesia strategies in this patient population.