Neuraxial blockade in patients with spinal stenosis: between a rock and a hard place.

摘要

Although severe or disabling neurologic complications after neuraxial block are rare, an epidemiologic series suggests that the frequency of some serious complications is increasing. The presence of new or progressive neurologic deficits necessitates prompt evaluation to detect potentially treatable sources of neurologic injury. In this setting, magnetic resonance imaging (MRI) is the preferred technique to diagnose spinal hematoma, epidural abscess, and mechanical trauma; acute spinal cord ischemia may be undetectable by conventional MRI. However, prior performance of a neuraxial technique may affect interpretation of the images. Radiologists must discern between benign "coincidental" findings, normal procedural-related changes, and those that represent pathologic processes. For example, spinal MRI findings in patients receiving continuous epidural analgesia may mimic those of epidural abscess (e.g., posterior epidural enhanced "lesion" with spinal cord compression) even in the absence of infection.2 Misinterpretation of MRI findings may lead to unnecessary therapies, including surgery. Despite these implications, MRI after uneventful neuraxial techniques remains largely undefined. Previous investigations have involved single cases or small series.