RESUMEN
Objective: To determine the diagnostic value of serum white blood cell [WBC] count, fever [>38[degree]C] and WBC rise [>10%] for bacterial meningitis in patients with severe traumatic brain injury [TBI]
Method: This cross-sectional study was conducted in Shahid Rajaei hospital affiliated with Shiraz University of Medical Sciences during a 1-year period from 2013 to 2014. We included consecutively all the patients with severe TBI admitted to our center during the study period who were febrile [>38[degree]C orally] and underwent lumbar puncture [LP] and analysis and culture of cerebrospinal fluid [CSF]. Laboratory analysis of CSF and blood were performed within 2 hours of LP. CSF culture was considered the gold standard for diagnosis of bacterial meningitis. The sensitivity, specificity, positive and negative predictive value [PPV, NPV] of peripheral blood WBC count, fever [>38[degree]C] and WBC rise [>10%] was determined according to the CSF culture
Results: Overall we included242 consecutive patients with severe TBI. The mean age of the participants was 32.8 +/- 17.4 years. Acinetobacter was the most common organism found in the CSF cultures. The sensitivity and specificity of peripheral WBC count [>10,000]was 48.4% [95% CI: 0.42-0.56] and 47% [95% CI: 0.37-0.58] respectively. The PPV and NPV was 13.1% [95% CI: 0.33-0.52] and 84.8% [95% CI: 0.42-0.61], respectively. The AUC for WBC count was 0.478 [95% CI: 0.37-0.58] indicating low accuracy for the diagnosis of bacterial meningitis. The AUC for WBC rise [>10%] and temperature >38[degree]C was0.460 [95% CI: 0.351-0.569] and 0.517 [95% CI: 0.410-0.624] respectively, both indicating low accuracy for diagnosis of bacterial meningitis
Conclusion: The results of the current study indicates that peripheral blood leukocyte count, fever [>38[degree]C] and WBC rise [>10%] is a non-reliable marker for diagnosis of bacterial meningitis in patients with severe TBI