Landmark Guided Lower Interscalene Block as a Rescue Approach in a Case of Elusive Supraclavicular Block for Elbow Surgery

Abstract

Dear Editor, Our case was an 18 yrs/m, weighing 54 kg without co morbidities presented with pain in right elbow and was posted for screw fixation of fracture capitulum. His routine blood work and airway examination were normal to undergo the surgery under supraclavicular block (SCB). On arrival, patient’s PR was 84/min, BP- 118/72 mm Hg, SpO2- 98% on room air. For right sided SCB, patient was placed supine, head turned to left side with shoulder depressed and needle was inserted lateral to subclavian artery pulsation just above the clavicle, posterolaterally. There was inadvertent puncture of subclavian artery each time, despite using standard techniques. Hence we decided to abandon standard SCB and proceed with lower interscalene block (LISB).Using modified Winnie’s approach interscalene groove was palpated and needle was inserted 2-3 cm below the classical interscalene block (ISB) site. Paresthesia was attained over whole upper limb and then Inj. Lignocaine + Adrenaline (2%) 10 ml along with inj. Bupivacaine 0.5% 10 ml was injected after repeated negative aspirations. A satisfactory sensory and motor blockade was obtained after 15 minutes of injection. Throughout the procedure, patient was continuously monitored and surgery was completed within 1.5h without any adverse event. The patient was shifted to ward. The block weaned off in 6 hrs and his vitals were stable throughout his course of stay in the hospital. Traditionally, the subclavian artery is an important relation of the brachial plexus for landmark guided SCB. However, anatomical variation may be present in as much as 50% of the population. [1] T1 nerve root supplies skin both above and below the elbow. Some authors have suggested a combined ISB + axillary block to get profound anaesthesia for elbow surgery. [2,3] Axillary nerve block was not contemplated in our case as optimal arm positioning was precluded due to severe pain at elbow. The advantages of LISB over SCB and ISB or ISB + axillary block are that it significantly reduces the risk of pneumothorax , inadvertent arterial puncture, ulnar sparing (as lower trunks of brachial plexus are more superficial in LISB) and avoids multiple injections. LISB also provides adequate anaesthesia and analgesia to whole upper limb which could be due to the relative proximity of the inferior trunks to the other components of brachial plexus as they become tightly bundled between the clavicle and first rib at this level.[2] Performing an LISB is easier due to its accessibility and shallow location of the brachial plexus, which may be favourable to those who disfavour or may not be comfortable with the supraclavicular approach. [4] Our case exemplifies that in those centres where ultrasound machine is unavailable and access to the brachial plexus for SCB by landmark technique remains elusive despite troubleshooting, lower interscalene block can be safely used to provide similar quality and extent of surgical anaesthesia.