Risk factors for complications and return to the emergency department after interscalene block using liposomal bupivacaine for shoulder surgery

Abstract

Exparel (liposomal bupivacaine)has recently gained favor for use in interscalene regional blocks for shoulder surgery. While effective for pain relief, this does have adverse effects that can lead to postoperative emergency department (ED) visits. This study aimed to identify any patient risk factors that are associated with complications leading to ED return visits owing to interscalene blocks using Exparelbefore shoulder surgery. A retrospective chart review was performed for all patients undergoing shoulder surgery with an Exparelinterscalene block in an 8-month period. For each patient, demographic information, comorbidities, type of block, postoperative complications, ED return visits, and readmissions were recorded. The 5-factor modified Frailty Index score and the Charlson Comorbidity Index score were calculated. Univariate and multivariate logistic regressions were conducted to identify risk factors associated with increased complications and return to the ED. Overall, 352 patients were included; most patients were men, were aged between 51 and 70 years, and had a body mass index of 25.0-35.0. Postoperative complications related to the Exparel interscalene block occurred in 58 patients (16.5%), including 37 minor complications (10.5%) and 21 major complications (6.0%) that led to return ED visits. Univariate analysis yielded American Society of Anesthesiologists (ASA) score (P = .03) as a significant predictor of minor complications. Multivariate logistic regression analysis yielded ASA score (P = .096; odds ratio, 1.64) as trending towardbeing a significant risk factor for minor complications. Univariate analysis yielded age (P = .006), ASA score (P = .009), and Charlson Comorbidity Index score (P = .002) as significant predictors of major complications. Multivariate logistic regression analysis yielded ASA score (P = .049; odds ratio, 2.25) as the only significant risk factor for major complications. Surgeons and anesthesiologists should strongly consider a patient's ASA score, in addition to his or her pulmonary and cardiac history, when deciding whether the patient is an appropriate candidate for an interscalene regional block using Exparelfor shoulder surgery.