Abstract No.: ABS3215: Superior trunk block: An unorthodox alternative to interscalene block for proximal humerus surgeries in patients with significant pulmonary disease

BACKGROUND AND AIMS: Proximal shoulder surgery in patients with compromised pulmonary function stipulated the utilisation of superior trunk block, which spares phrenic nerve,as an alternative to interscalene block. This modificationallows patients to execute normal respiration perioperatively.This case series reports the efficacy of the block. METHODS: Eight patients aged between 40 years to 80 years with significant restrictive, obstructive pulmonary disease and post-COVID 19 sequelae, posted for proximal humerus surgeries received the block. The block was performed under ultrasound guidance using 23 gauge Quincke spinal needle with 1:1 local anaesthetic mixture of 2% lignocaine+adrenaline and 0.5% bupivacaine with total volume injected being 15ml. The outcomes measured were loss of shoulder abduction, numbness of shoulder and pain relief, numbness of arm ,sonographic assessment of diaphragm movement, oxygen saturation perioperatively and closed-circuit measurement of the tidal volume generated. RESULTS: Seven patients with superior trunk block achieved complete surgical anaesthesia of proximal shoulder. There was solitary use of dexmedetomidine for a patient with severe anxiety. Two patients required oxygen supplementation throughout the intraoperative period extending to post-operative period as well. Sonographic assessment intraoperatively and post-operatively disclosed adequate diaphragmatic excursion in all patients (table 1). Post-operative pain scores revealed satisfactory pain relief. CONCLUSION: Effective surgical anaesthesia and analgesia is delivered considerably with superior trunk block for surgeries of proximal humerus in patients with compromised pulmonary function by sparing phrenic nerve and is an appropriate substitute for interscalene block.