The Efficacy of Additional Intravenous Patient-controlled Analgesia to the Interscalene Block in Arthroscopic Shoulder Surgery: A Prospective Randomized Controlled Study

ABSTRACT

BACKGROUND: The purpose is to determine the efficacy of additional intravenous patient-controlled analgesia (IV-PCA) by comparing the analgesic effects between interscalene block (ISB) combined with IV-PCA and single ISB after arthroscopic shoulder surgery. METHODS: A total of 213 patients who underwent arthroscopic shoulder surgery were divided into two groups based on the type of perioperative anesthesia. The single ISB group included 100 patients, while the IV-PCA group included 113 patients. The visual analogue scale for pain (VAS pain) scores were assessed at 12, 24, and 48 hours postoperatively in accordance with shoulder pathology. Postoperative narcotics-related complications and consumption of additional non-steroidal anti-inflammatory drugs between the two groups were compared. RESULTS: VAS pain showed no significant difference between the two groups at most points of the postoperative timeline, regardless of shoulder pathology, except in patients with rotator cuff repair at postoperative 24 hours. Although the IV-PCA group showed a statistically lower VAS pain score than the ISB group at postoperative 24 hours (p=0.04), the difference in the VAS pain score was only 9.0 mm in patients with rotator cuff repair. Narcotics-related complications were observed more frequently in the IV-PCA group than in the ISB group for patients with rotator cuff repair. CONCLUSIONS: Additional IV-PCA demonstrated no booster effect for immediate pain control in patients undergoing arthroscopic shoulder surgery with preoperative single ISB. Furthermore, patients with IV-PCA experienced greater narcotics-related complications.