Effect of Ultrasound-Guided Extra-Prevertebral Fascial Suprascapular Nerve and Infraclavicular Brachial Plexus Block on Postoperative Analgesia and Phrenic Nerve Function in Shoulder Arthroscopy: A Pilot Study.

Abstract

Purpose: The suprascapular nerve is situated between the prevertebral fascia and the superficial layer of deep cervical fascia and on the surface of the middle and posterior scalene muscles before it reaches the suprascapular notch. Consequently, we hypothesized that injecting local anesthetics (LAs) there would introduce a new block approach for blocking the suprascapular nerve, ie, extra-prevertebral fascial block. We assessed the postoperative analgesic effect, as well as the incidence of diaphragmatic paralysis 30 minutes after the block.

Methods: 30 patients undergoing elective shoulder arthroscopic rotator cuff repair surgery were recruited in this study. Before the induction of general anesthesia, 15 mL of 0.5% ropivacaine was administered to perform an extra-prevertebral fascia suprascapular nerve block (10 mL) and an infraclavicular brachial plexus block (5 mL, primarily targeting the axillary nerve). All patients received intravenous patient-controlled analgesia (PCA) after surgery. The postoperative pain was scored with Numeric Rating Scale (NRS), along with the opioid consumption in the first 24 h after surgery. The incidence of hemi-diaphragmatic paralysis (HDP) was measured 30 minutes after the block.

Results: All patients received the successful block. The resting NRS pain scores at 1h, 6h, 12h, and 24h postoperatively were 0 [0, 2], 0 [0, 2], 1 [0, 2], and 2 [1, 3], respectively. The oral morphine equivalent (OME) consumption at 24 hours after surgery was 18 [12,30] mg. No patients experienced HDP (complete or partial) 30 minutes after the block.

Conclusion: Compared with the posterior approach, this novel technique is efficient and has a higher success rate of blockade. It eliminates the need for patients to change positions, thereby improving comfort. Additionally, when combined with the infraclavicular brachial plexus block, it can effectively block the suprascapular nerve, providing satisfactory postoperative analgesia without the HDP at 30min after blockade compared to the anterior approach.