Incidence of neurologic complications related to thoracic epidural catheterization

Due to potential neurologic sequelae, the risk:benefit ratio of thoracic epidural analgesia is controversial. Surprisingly, however, few available data address neurologic complications. The incidence of neurologic complications occurring after thoracic epidural catheterization was studied in patients scheduled for abdominal or abdominothoracic surgery.

A total of 4,185 patients were studied, including 2,059 during the prospective phase of the study and 2,126 during the retrospective phase. After thoracic epidural catheterization, all patients received general anesthesia. Patients' neurologic status was assessed by an anesthesiologist using clinical criteria after operation and after epidural catheter removal. If neurologic complications were suspected, a neurologist was consulted. The incidence of specific complications was compared for different thoracic puncture sites: upper (T3/4-6/7), mid (T7/8-8/9), and lower (T9/10-11/12) catheter insertion levels.

The overall incidence of complications after thoracic epidural catheterization was 3.1% (n = 128). This included dural perforation (0.7%; n = 30); unsuccessful catheter placement (1.1%; n = 45); postoperative radicular type pain (0.2%; n = 9), responsive to catheter withdrawal in all cases; and peripheral nerve lesions (0.6%; n = 24), 0.3% (n = 14) of which were peroneal nerve palsies probably related to surgical positioning or other transient peripheral nerve lesions (0.2%; n = 10). No signs suggesting epidural hematoma were recognized, and there were no permanent sensory or motor defects attributable to epidural catheterization. Unintentional dural perforation was observed significantly more often in the lower (3.4%) than in the mid (0.9%), or upper (0.4%) thoracic region. A single patient experienced severe respiratory depression after receiving epidural buprenorphine but recovered without sequelae.

Thoracic epidural catheterization for abdominal and thoracoabdominal surgery is not associated with a high incidence of serious neurologic complications. In fact, the incidence of puncture- and catheter-related complications is less in the mid and upper than in lower thoracic region, and the predicted maximum risk for permanent neurologic complications (upper bound of the 95% confidence interval) is 0.07%.