Title: Fascial layers influence the spread of injectate during ultrasound guided infraclavicular brachial plexus block – a cadaver study.

Investigating team: David Brenner, Padraig Mahon, Gabriella Iohom, Michael Cronin, Carrie O’Flynn, George Shorten

Background: Infraclavicular brachial plexus block is commonly performed to facilitate upper limb surgery. Even when ultrasound guidnace is used, reported failure rates range from 2.3% to 20%. One possible explanation for block failure is the presence of a fasical layer or layers close to the point of injection that influence the spread of injectate and thus limit block efficacy.

Objective: Investigate whether fascial layers of the neurovascular sheath could influence the success of infraclavicular brachial plexus block.

Preliminary Results: Well defined fascial layers were identified at dissection in 7 out of 12 infraclavicular spaces studied. These fascial layers impeded the spread of dye injectate substantially in six cases and partially in one case. The sensitivity and specificity of ultrasonography and haptic sensation for detection of fascial layers were poor.

Current Status: In press British Journal of Anaesthesia.