Methicillin-resistant Staphylococcus aureus epidural abscess after transforaminal epidural steroid injection.

Transforaminal epidural steroid injections are provided frequently for patients with lumbar radiculopathy, having demonstrated efficacy and safety. We present a patient who developed methicillin-resistant Staphylococcus aureus epidural abscess 11 days after a transforaminal epidural steroid injection. The abscess required surgical intervention and intravenous vancomycin. Fortunately, the patient made a full recovery, and continues to do well one year later. The incidence, etiology and treatment of epidural injection-related infections are reviewed.

Paresthesiae during radiofrequency neurolysis of lumbar sympathetic trunk in CRPS: human evidence of a sympatho-sensory connection?

Radiofrequency heat lesioning has been advocated to prolong the duration of therapeutic effect of lumbar sympathetic block in Complex Region Pain Syndrome (CRPS) of the lower extremity. Prior to radiofrequency lesioning of the lumbar sympathetic trunk, sensory and motor stimulation may be used to verify that the active needle tip is not adjacent to a spinal nerve to avoid unwanted neural injury. However, the value of sensory stimulation to aid in precise needle positioning at the desired target remains controversial. In this report we describe our observations using sensory stimulation to aid in needle placement for radiofrequency lesioning. We confirm a novel observation that paresthesiae to the lumbar sympathetic trunk is possible and hypothesize on pathophysiologic meaning. Two representative patients are presented who underwent sensory stimulation of the lumbar sympathetic trunk during needle placement for lumbar sympathetic radiofrequency neurolysis. Sensory stimulation was elicited at the L3 or L4 vertebral level using a 15 cm insulated radiofrequency needle with a 5-mm active tip. During sensory stimulation, patients described paresthesiae to the ipsilateral buttock and lower extremity. Stimulation intensity was less than 0.8 V at 50 Hz at impedance of 300 Ohms or less. Motor stimulation did not occur up to the maximum voltage tested (2.0 V at 2 Hz) Sensory stimulation of the lumbar sympathetic trunk may be used to aid in localization of the active tip of the radiofrequency needle, in preparation for lesioning. A dermatomal sensory pattern was observed, suggesting that afferent sensory fibers travel in the lumbar sympathetic trunk. The implications of this observation for understanding the mechanism of CRPS-related pain are discussed.

Randomized prospective comparison of forced air warming using hospital blankets versus commercial blankets in surgical patients.

BACKGROUND: The purpose of this study was to evaluate the efficacy of an experimental approach to forced air warming using hospital blankets or a Bair Hugger warming unit (Augustine Medical Inc., Eden Prairie, MN) to create a tent of warm air. METHODS: Adult patients undergoing major surgery were studied. Patients were randomized to receive forced air warming using either a commercial Bair Hugger blanket (control group, n = 44; set point, 43 degrees C) or standard hospital blankets (experimental group, n = 39; set point, 38 degrees C). Distal esophageal temperatures were monitored. Patients were contacted the following day regarding any problems with the assigned warming technique. RESULTS: Surface area covered was 36 +/- 12% (mean +/- SD) in the experimental group and 40 +/- 10% in the control group. Final temperatures at the end of surgery were similar between groups: experimental, 36.2 +/- 0.6 degrees C; control, 36.4 +/- 0.7 degrees C. A similar number of patients had esophageal temperature less than 36 degrees C at the end of surgery in both groups (experimental, 12 of 39 [31%]; control, 12 of 44 [27%]). The majority of patients were satisfied with their anesthetic and warming technique: experimental, 38 of 39 patients; control, 44 of 44 patients. There were no thermal injuries. CONCLUSIONS: Standard hospital blankets heated to 38 degrees C forced air were equally as effective as commercial blankets heated with forced air at 43 degrees C. However, based on concerns expressed by the manufacturer, this experimental technique should not be used until further safety evaluation has been undertaken.