Phrenic nerve block after interscalene brachial plexus block. Case report.

Background And Objectives: Phrenic nerve block is a common adverse event of brachial plexus block. However, in most cases it does not have any important clinical repercussion. The objective of this work was to report a case with phrenic nerve block with respiratory repercussions in a patient with chronic renal failure who had an extensive arteriovenous fistula created under perivascular interscalene brachial plexus block.