Continuous Catheter Versus Single-Shot Interscalene Block in Shoulder Surgery: A Review and Recommendations for Postoperative Pain Management

Abstract

Shoulder arthroscopic and arthroplastic surgeries are associated with significant postoperative pain, which can delay recovery and increase opioid consumption. Interscalene blocks (ISBs) are a commonly used method to manage this pain, either as single-shot injections or continuous catheter infusions (CISBs). This review synthesizes findings from studies conducted in the past five years, comparing the efficacy, complications, and outcomes of single-shot ISBs versus CISBs for postoperative pain management in shoulder surgeries. Current literature highlights key differences: single-shot ISBs provide significant immediate postoperative pain relief, whereas CISBs offer prolonged analgesia beyond 48 hours, reduced opioid consumption, and enhanced recovery outcomes. However, CISBs carry a higher risk of complications and procedural complexity compared to single-shot ISBs. Both single-shot ISBs and CISBs present effective options for postoperative pain control in shoulder surgery patients. Single-shot ISBs may be preferable for patients seeking immediate pain relief with fewer complications, while CISBs are beneficial for those requiring prolonged analgesia. The choice of technique should be individualized based on the patient's needs, expected recovery, and potential risk factors.

Keywords: continuous interscalene block; opioid reduction; pain management; shoulder surgery; single-shot interscalene block.

Figure 1. Brachial Plexus Anatomy

The C5 to T1 nerve roots pass between the anterior and middle scalene muscles. The superior, middle, and inferior trunks of the brachial plexus are formed as these nerve roots descend through the interscalene groove. Image credit: Kalie L. Nuss via iArtbook

Figure 2. Anatomical Landmarks for ISB Administration

(a) Surface landmarks used to perform an ISB. (b) The patient is flexing their neck to tense the SCM, which aids in identifying the posterior border of the SCM-C and the ISG. CC, cricoid cartilage; SCM-S, sternal head of sternocleidomastoid; SCM-C, clavicular head of sternocleidomastoid Image credit: Reproduced with permission from: Wilson EH, Klesius LL. Interscalene block procedure guide. In: UpToDate, Connor RF (Ed), Wolters Kluwer. Copyright © 2024 UpToDate, Inc. and/or its affiliates. All rights reserved [21].

Figure 3. Ultrasound Image Showing the Brachial Plexus and Surrounding Anatomy at the ISG

The solid white line highlights the brachial plexus, while the dashed white line indicates the superior cervical plexus. MS, middle scalene muscle; AS, anterior scalene muscle; IJ, internal jugular vein; VA, vertebral artery; CA, carotid artery Image credit: Reproduced with permission from: Wilson EH, Klesius LL. Interscalene block procedure guide. In: UpToDate, Connor RF (Ed), Wolters Kluwer. Copyright © 2024 UpToDate, Inc. and/or its affiliates. All rights reserved [21].