Shoulder and Upper Arm Surgery Anaesthesia with Interscalene Approach of Brachial Block and Sedation versus Same Method Adjunct with Additional Suprascapular Nerve Block: A Randomised Controlled Study

Introduction: Interscalene Brachial Plexus Block (ISBPB) provides optimal analgesia for shoulder and upper arm surgery. However, higher incidence of phrenic nerve palsy limits the application of ISBPB for patients with limited pulmonary reserve. The Supplemented Suprascapular Nerve Block (SSNB) is a landmark based technique that is believed to block the sensory fibres supplying major part of shoulder joint, as well as, supraspinatus and infraspinatus muscles.

Aim: To compare the analgesic effect and duration of sensory block in interscalene versus interscalene with SSNB block for shoulder and upper arm surgery.

Materials and Methods: This double-blinded randomised controlled study was conducted in a Tertiary Care Institute, from April 2021 to March 2022. Eighty patients posted for shoulder and upper arm surgery were divided into two equal groups (group A and B). In group A (n=40), 30 mL 0.5% levobupivacaine in ISBPB and in group B (n=40), 15 mL 0.5% levobupivacaine in ISBPB+15 mL 0.5% levobupivacaine in SSNB were administered. Demographic data, sensory and motor block, onset times and durations, time to administer first rescue analgesic, total analgesic requirement, indications of upper arm surgeries, surgical bleeding and surgeon’s satisfaction score, postoperative Visual Analogue Scale (VAS) score were recorded for each patient.

Results: The onset and duration of sensory and motor block was significantly faster and longer in group B. Consequently, time to administer first rescue analgesic in group A vs group B (325.88±33.23 vs. 348.34±37.12, respectively) minutes were significantly delayed and lesser in amount in group B. On the other hand, suprascapular block reduced the odds of block-related respiratory (group A vs group B are 14 and 10, respectively) complications. In group B postoperative VAS score at 24 hour was significantly lower (p-value <0.05) than group A was (3.5 vs 4.5). Intraoperative haemodynamic parameters were comparable among two groups throughout the study period.

Conclusion: SSNB when supplemented with Interscalene Block (ISB) could be an effective adjunct for shoulder and upper arm surgery. This combination prolongs the sensory blockade duration, reduces requirement of analgesics and side-effects in postoperative period.