Subdural spread of local anesthetic agent following thoracic paravertebral block and cannulation.

THORACIC paravertebral block has been shown to be effective for surgical anesthesia when the afferent pain input is predominantly unilateral from the chest. We describe a patient scheduled for right thoracotomy with combined paravertebral–general anesthesia who had abnormal responses to local anesthetic injection administered via the paravertebral catheter. The catheter subsequently was found to be in the subdural space. To our knowledge, this is the first report to be published in the anesthesia literature of a subdural blockade occurring during intended cannulation to paravertebral space.