Depression, night terrors, and insomnia associated with long-term intrathecal clonidine therapy.

Intraspinal clonidine is an effective adjunct to intrathecal/epidural opioid administration. We report a case of neuropathic pain treated with intraspinal analgesics in which depression, insomnia, and night terrors developed in association with intraspinal clonidine.

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

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.

Successful treatment of spontaneous cerebrospinal fluid leak headache with fluoroscopically guided epidural blood patch: a report of four cases.

Spontaneous cerebrospinal fluid (CSF) leak is a rare clinical entity that may result in disabling headaches. It occurs as a result of dural defects, and the initial symptoms resemble those of postdural puncture headache. However, the positional headache can later evolve into a persistent chronic daily headache. The diagnosis of spontaneous CSF leak can be very challenging, but increasing awareness and improved diagnostic techniques are yielding ever more cases. When conservative management fails, the pain management clinician is called upon to administer an epidural blood patch. The success of this technique is dependent upon accurate diagnosis of the site of leakage and targeted epidural administration of the blood patch to this area. In this report, we describe four consecutive cases that were referred to our pain management department over an 18-month period and were successfully treated with site-directed epidural blood patches.

Buprenorphine added to the local anesthetic for axillary brachial plexus block prolongs postoperative analgesia.

BACKGROUND AND OBJECTIVES: Buprenorphine added to local anesthetic solutions for supraclavicular block was found to triple postoperative analgesia duration in a previous study when compared with local anesthetic block alone. That study, however, did not control for potentially confounding factors, such as the possibility that buprenorphine was affecting analgesia through intramuscular absorption or via a spinal mechanism. To specifically delineate the role of buprenorphine in peripherally mediated opioid analgesia, the present study controlled for these 2 factors. METHODS: Sixty American Society of Anesthesiologists (ASA) P.S. I and II, consenting adults for upper extremity surgery, were prospectively assigned randomly in double-blind fashion to 1 of 3 groups. Group I received local anesthetic (1% mepivacaine, 0.2% tetracaine, epinephrine 1:200,000), 40 mL, plus buprenorphine, 0.3 mg, for axillary block, and intramuscular (IM) saline. Group II received local anesthetic-only axillary block, and IM buprenorphine 0.3 mg. Group III received local anesthetic-only axillary block and IM saline. Postoperative pain onset and intensity were compared, as was analgesic medication use. RESULTS: The mean duration of postoperative analgesia was 22.3 hours in Group I; 12.5 hours in group II, and 6.6 hours in group III. Differences between groups I and II were statistically significant (P =.0012). Differences both between groups I and III and II and III were also statistically significant (P <.001). CONCLUSIONS: Buprenorphine-local anesthetic axillary perivascular brachial plexus block provided postoperative analgesia lasting 3 times longer than local anesthetic block alone and twice as long as buprenorphine given by IM injection plus local anesthetic-only block. This supports the concept of peripherally mediated opioid analgesia by buprenorphine.