THE C-REACTIVE PROTEIN FOR DETECTION OF EARLY INFECTIONS AFTER LUMBARMICRODISCECTOMY

The tendency for short hospitalization after lumbar microdiscectomy im plies the need for early confirmation or disproval of serious postoper ative infections such as spondylodiscitis or deep wound infections. Th e C-reactive protein (CRP) is a well-known screening parameter for mon itoring postoperative infectious complications in other fields. Our ob jective was to establish the diagnostic significance of CRP-in compari son with ESR and WBC-for monitoring infectious complications after lum bar microdiscectomy. Over a 15 months period we studied prospectively a homogeneous group of N = 400 patients with lumbar disc herniations w ho were operated on a single level for the first time. CRP, ESR and WB C values were determined in all patients pre-operatively, and on posto perative days 1 and 5. Clinical and laboratory findings were correlate d and the diagnostic significance of CRP, ESR and WBC calculated. N = 385 (96%) patients had an uneventful postoperative course. N = 15 (4%) patients developed infectious complications, of which N = 6 (1.5%) we re unrelated and N = 9 (2.5%) related to surgery. Evaluation of the la boratory values showed: The CRP baseline is a very individual value of no prognostic relevance. A high postaggression peak is typical and es sential as a reference value for only the future time course will disc lose any infection. We found 0% false negative and 4% false positive r esults on day 5. The sensitivity for serial CRP testing was calculated as 100% and specificity as 95.8%. ESR(sensitivity: 78.1%/specificity: 38.1%) and WBC(sensitivity: 21.4%/specificity: 76.8%) both failed to reach such distinct diagnostic significance on day 5. The C-reactive p rotein has thus proved to be a reliable, simple and economical screeni ng test for infectious complications after lumbar microdiscectomy, sup erior to classical laboratory parameters.