Efficacy of intertruncal and corner-pocket approaches of ultrasound-guided supraclavicular block in terms of ulnar nerve blockade: A randomised controlled study

BACKGROUND AND AIMS: The incidence of ulnar nerve sparing has declined with the corner-pocket approach of the supraclavicular block (SCB), however, it continues to persist. A recent technique of SCB, the intertruncal approach, separately blocks each trunk of the brachial plexus. Thus, we hypothesised that the intertruncal approach results in a complete ulnar nerve blockade. METHODS: Eighty-eight patients were randomised to undergo SCB using an ultrasound (USG)-guided corner-pocket or intertruncal approach and were compared primarily regarding the complete sensory and motor blockade of the ulnar nerve and all four nerves (ulnar, radial, median and musculocutaneous nerves) at 15 min. Secondary objectives included time required for block performance, patient discomfort score, time to readiness for surgery and duration of sensory blockade of the ulnar nerve. Continous data were compared using an independent t-test, and categorical data were compared using the Chi-square test. RESULTS: The proportion of participants with complete sensory (30/44 vs. 14/44, P < 0.001) and complete motor (22/44 vs. 7/44, P < 0.001) blocks in the ulnar nerve and all four nerves at 15 min was significantly higher in the intertruncal group. Block performance time and patient discomfort score were higher in the intertruncal group (P < 0.001). The total duration of sensory blockade in the ulnar nerve was more in the corner-pocket group (P < 0.001). CONCLUSION: USG-guided intertruncal approach is superior to the corner-pocket approach of SCB regarding a complete ulnar nerve blockade.