Delayed recovery of radial nerve function after axillary block in a patient receiving ipsilateral ulnar nerve transposition surgery.

A 68-year-old female who underwent right ulnar nerve transposition surgery under axillary block (AB) by dual-technique (paresthesia and axillary artery penetration techniques) developed postoperative wristdrop. Physical examination showed local hematoma formation with ecchymosis at her right axillary region. Both ultrasonography and nerve conduction studies on her brachial plexus revealed neither direct hematoma compression, intraneural hematoma, nor peripheral neuropathy. Fortunately, she was completely restored to her right hand function 20 h after anesthesia, and was discharged without sequelae 17 days later. In this case, delayed recovery of radial nerve function after AB was suspected and the mechanism which led to this unusualness is discussed.