Negative aspiration for cerebral spinal fluid does not assure proper placement of epidural catheter.

Inadvertent subarachnoid injection of a local anesthetic during the conduct of epidural anesthesia may have a devastating effect on the patient. The incidence of dural puncture with an epidural catheter has been reported to range from 0.5% to 0.9%. This case report demonstrates that, despite negative aspiration of cerebral spinal fluid from the catheter, subarachnoid injection of a local anesthetic can occur.