Novel technique for reversing phrenic nerve paresis secondary to interscalene brachial plexus block

Interscalene brachial plexus block is the reference analgesic technique for shoulder surgery. Phrenic nerve palsy with hemidiaphragmatic paresis is an established complication that results in symptomatic dyspnoea in a small number of subjects, and is poorly tolerated. Established management is supportive and assumes that, once administered, the duration of the block is unalterable. A case is presented of saline washout as a rescue measure for severe dyspnoea due to phrenic nerve palsy following interscalene brachial plexus block. To the authors' knowledge, this is the first case of this method used to reverse a single-injection brachial plexus block.