To the Editor:—

The cases presented by Dr. Jonathan L. Benumof 1are invaluable contributions to our understanding of the risks associated with performing peripheral nerve blocks. However, it is important to acknowledge that these are malpractice cases, and that peripheral nerve blocks performed in appropriate conditions by properly trained and experienced practitioners are safe and effective in providing anesthesia and analgesia 2and are cost effective. 3 

We strongly disagree with the statements, “Performing an interscalene block (ISB) during general anesthesia (GA) . . . is a common procedure” (introduction) and “GA can be considered as a relative contraindication for ISB” (discussion). 1Of all the peripheral nerve blocks we perform, interscalene blocks in an adult should be performed awake. General anesthesia should be considered as an absolute rather than a relative contraindication. In our institution, we only perform interscalene blocks before or after surgery in awake patients (Ramsey score < 3).

In case 3, the patient was anesthetized because of “coughing, straining, and neck movement.”1We strongly believe that in this specific situation, general anesthesia is not the solution, but removing the needle and offering alternative postoperative pain therapy approaches should be considered the standard. Anyone performing peripheral nerve blocks needs to acknowledge that every patient is not necessarily a good candidate and that alternative therapies exist.

Because in three patients a nerve stimulator was used, if the needles were in the spinal cord, one should expect an intense motor response. Perhaps epidural or intrathecal injections leading to acute spine compression also deserve consideration in the differential diagnosis. This differential diagnosis is important because it suggests that magnetic resonance imaging performed immediately after the block might have provided insight and might have led to an early surgical decompression.

We also insist on using a 25-mm needle and introducing the needle in a posterior and caudal direction and agree that this technique minimizes the risk for the needle’s entering the intervertebral space. However, many anesthesiologists have performed thousands of interscalene blocks without similar catastrophic outcomes using a 50-mm needle. In our opinion, these four cases reinforce the importance of proper setup, training, and experience. There is an increased demand for peripheral nerve blocks, but many resident training programs do not provide formal training in peripheral nerve blocks. Our residents spend a minimum of 1 month in a peripheral nerve block rotation and perform an average of 100–150 upper and lower extremity blocks. Many of our residents come back for a second month and even for a third month. In September 1999, we began a fellowship program. In addition, our residents are given educational materials, including a book and videos, and have access to dissection sessions. Similar programs exist in other institutions but are by far the exception, although they should be the rule. 4 

In conclusion, the cases presented by Dr. Benumof represent extreme complications of interscalene blocks. Residents and anesthesiologists performing these blocks should be aware of them. Prevention of these complications includes the proper selection of patients and the performance of blocks either before or after anesthesia in patients who are awake or mildly sedated.

Benumof JL: Permanent loss of cervical spinal cord function associated with interscalene block performed under general anesthesia. Anesthesiology 2000; 93: 1541–4
Auroy Y, Narchi P, Messiah A, Litt L, Rouvier B, Samii K: Serious complications related to regional anesthesia: Results of a prospective survey in France. Anesthesiology 1997; 87: 479–86
Pavlin DJ, Rapp SE, Polissar NL, Malmgren JA, Koerschgen M, Keyes H: Factors affecting discharge time in adult outpatients. Anesth Analg 1998; 87: 816–26
Chelly JE, Hagberg CA, Gebhard R, Greger J, Khan A: Teaching peripheral nerve blocks to anesthesiology residents (abstract). Anesthesiology 2000; 93: A1204