Abstract ID: A01

Abstract Title: Hs-CRP as a Serum Inflammatory Marker of Radiculitis

Poster Type: Poster


ABSTRACT BODY

Introduction:Patients with high serum levels of high-sensitivity C reactive protein (hs-CRP) demonstrate a poorer recovery following lumbar spine surgery. The efficacy of lumbar epidural steroid injections (LESI) for the treatment of lower extremity radiculitis varies among patients. We examined the systemic inflammatory and pain responses in patients with lumbar disc herniations with different pathological intervertebral disc changes.

Materials and Methods:After patient informed consent and IRB approval were obtained, 60 patients were scheduled for LESI therapy every two weeks for three injections. Prior to injection therapy the following laboratory tests were performed: CBC, hs-CRP, and ESR. Each patient had a history of a lumbar disc herniation noted by MRI. A numeric pain intensity score (NPI 0-10) was obtained prior to each LESI and at 6 wks following LESI therapy. Patients were excluded from the study if they had taken any oral steroids or NSAIDS prior to entering this study. No patient was included in this study if they had a history of smoking, heart disease or an inflammatory disease. Each patient had a decreased sensation to pin prick, muscle weakness and/or a dampened or absent reflex in one lower extremity. All patients in this study had a numeric pain intensity score (0-10) >6 and were taking mild opioids and muscle relaxants for pain control. Four groups of fifteen patients were divided as follows: a) annular tear, b) disc prolapse, c) disc extrusion and d) sequestered disc. LESI were scheduled two weeks apart and were done with fluoroscopy using 80 mg of triamcinolone. If a patient had pain relief after the first or second LESI no further injections were done. All patients returned in 6 wks from the time of the initial injection. Pain relief was defined as a decrease of >75% from baseline. Fisher exact was used for statistical comparison of the pain score in different groups and Mann-Whitney Rank Sum Test was used for comparing the hs-CRP levels with a p < 0.5 considered significant.

Results:: There were no differences between groups with respect to demographics. No patient in this study had an elevated CBC or ESR. The hs-CRP elevations in the Groups were noted as follows: a) 0% (0/15); b) 20% (3/15); c) 80% (12/15 (p<0.05 as compared to a); and d) 73% (11/15) (p<0.05 as compared to a). LESI was more efficacious in the non-contained disc herniation groups (table 1). The results of this study suggest that the efficacy of LESI in this population is inversely related to hs-CRP levels.

Discussion:The results of this study suggest that systemic inflammatory responses can occur in patients with contained or non-contained disc herniations but the incidence is higher with non-contained herniations. These results may be related to nerve root compression (Group b) injury with subsequent nerve root inflammation. However, a more pronounced inflammatory response was noted in those patients with release of inflammatory substances from the nucleus pulposus. A persistent elevation in the hs-CRP as a marker of continued radiculitis may be one explanation why LESI is not effective in some patients.

ATTACHED FILES

A01_table.doc





Reg Anesth Pain Med 2004; 29(2):A01