The authors examined 15 years of data from a local medical center and 3 decades of records from the National American Society of Anesthesia Closed Claims Project. Complications of regional anesthesia were reviewed and classified as related to: 1) peripheral nerve function; 2) respiratory function; 3) central nervous system dysfunction; and 4) cardiovascular function. When they examined the data from the local medical center, they found that there were 41 patients with complications associated with interscalene blocks during the interval from 1991 through 2005. Of these, there were 27 peripheral neurologic complications, 3 CNS complications, 6 respiratory complications, and 5 cardiovascular complications. The estimated complication rate was 1.1%. Of the neurologic complications, the majority were classified as either C5-6 palsy, upper trunk injury, or brachial plexopathy. Of note, they identified 3 radial nerve palsies, 3 musculocutaneous palsies, 1 ulnar nerve palsy, and 1 median neurapraxia. They found that there was a strong correlation between the complication rate and the number of blocks performed by each anesthesiologist. Mean complication rate for anesthesiologists performing less than 100 blocks was 5%, whereas the mean complication rate for anesthesiologists performing more than 100 blocks was 1%. Examination of the national database revealed a similar array of complications. It is of note that 3 patients died secondary to complications associated with the nerve block.
The significance of this study is that substantial complications can follow the use of interscalene block for upper extremity surgery and that chronic peripheral nerve injuries can occur. The authors note that the burden of treatment of these adverse outcomes often falls on the upper extremity surgeon rather than the anesthesiologist.
Nerve, Block, Regional, Anesthesia, Interscalene, Complications