ABSTRACT
PURPOSE: To compare the efficacy of a subacromial injection (SAI) with a single-shot interscalene block (ISB) for immediate postoperative pain relief after outpatient arthroscopic rotator cuff repair (ARCR). METHODS: We performed a retrospective chart review of consecutive patients who underwent ARCR. Patients received either an ISB before the procedure or an SAI after the procedure. Preoperative baseline patient characteristics were collected and compared. Visual analog scale (VAS) pain scores were recorded preoperatively, at 15-minute intervals over a 120-minute period in the postanesthesia care unit (PACU), and at discharge. Differences in VAS scores between groups were compared with known values of the minimal clinically important difference, and the percentage of patients with VAS scores below the patient acceptable symptom state was tabulated. Differences between preoperative characteristics were assessed using the Mann-Whitney U, Fisher exact, or χ2 test. The Mann-Whitney U test was also used to evaluate VAS scores and total time spent in the PACU between groups. RESULTS: The median VAS score was significantly lower in the ISB group at PACU admission, at all intervals throughout the PACU stay, and at discharge (P < .0001). The median total time in the PACU was 107 minutes (25th percentile-75th percentile, 90-120 minutes) and 210 minutes (25th percentile-75th percentile, 175-274 minutes) in the ISB and SAI groups, respectively (P < .0001). Between-group differences in VAS scores were greater than the values of the minimal clinically important difference at each measured interval. A total of 98% and 67% of patients in the ISB and SAI groups, respectively, were discharged with VAS scores below the patient acceptable symptom state of 3. CONCLUSIONS: Patients receiving an ISB experience significantly less pain than those receiving an SAI. In addition, they are discharged home from the PACU in half the time as patients receiving an SAI. On the basis of the comparative efficacy, an SAI cannot replace an ISB after ARCR. The ISB should therefore remain the standard of care as an adjunct to postoperative analgesia for patients who undergo outpatient ARCR. LEVEL OF EVIDENCE: Level III, retrospective, comparative therapeutic trial.
