Tunneled epidural catheter infections in noncancer pain: increased risk in patients with neuropathic pain/complex regional pain syndrome.

ABSTRACT

BACKGROUND AND OBJECTIVE: Tunneled epidural catheters are often used to control pain and facilitate rehabilitation in patients with regional pain syndromes. A cohort retrospective study design was undertaken to evaluate the risk of catheter-related infection in patients who underwent a TEC placement to manage their chronic noncancer regional pain over a 5-year period. METHODS: There were 260 tunneled epidural catheters placed in 218 patients accounting for a total of 10,985 catheter-days. Of these, 230 catheters were placed in patients with neuropathic pain (90% of whom had complex regional pain syndrome) and 30 catheters in patients with somatic pain. RESULTS: There were 24 epidural space infections in symptomatic patients, 23 of whom were in the neuropathic pain group-22 had complex regional pain syndrome. Additionally, tunneled epidural catheters had to be discontinued in 34 patients because of superficial infection or suspicion of infection; 33 of these were in the neuropathic pain group. The differences in the infection rates were significantly higher in the neuropathic pain group compared to the somatic group. When analyzed to an infection index per 1,000 catheter-days, the rate of infection rate was 5.51 for the patients with neuropathic pain and 2.43 for the patients with somatic pain. The rates for deep and superficial infections were 2.26 and 3.25, respectively, per 1000 catheter-days for the neuropathic pain group compared to 1.22 for both deep and superficial infections in the patients with somatic pain. There were 6 frank epidural abscesses upon contrast-enhanced magnetic resonance imaging examinations of the spine, 1 epidural phlegmon and 2 patients displayed mild or questionable epidural enhancement on magnetic resonance imaging, suggestive of epidural inflammation. All these magnetic resonance imaging abnormalities were detected in patients with complex regional pain syndrome. Two of the patients with epidural abscesses underwent surgical exploration and drainage of the epidural abscess, though no neurologic deficits were observed in any of the patients. CONCLUSIONS: The higher risk of tunneled epidural catheter infection observed in patients with neuropathic pain (particularly complex regional pain syndrome) warrants further study.