Procalcitonin as a diagnostic marker in patients with aspiration after closed head injury

Aspiration of gastric content frequently induces early onset of pneumonia in patients with impaired consciousness after closed head injury and thus worsens the prognosis. Early detection of aspiration and appropriate therapy are essential. The purpose of the study was to assess the diagnostic value of procalcitonin (ProCT) in aspiration of gastric content and to evaluate its prognostic impact in patients with closed head injury.

Twenty-three patients with isolated closed head injury (Glasgow Coma Scale [GCS] score < or = 8) were studied. Bronchoscopy was done on admission; chest radiographs and routine laboratory examination including C-reactive protein were performed daily. ProCT was analyzed 12, 24, 36 and 72 hours after trauma using an immunoluminometric assay.

ProCT was higher throughout the study period in 9 patients with persistent radiological signs suspect for aspiration of gastric content and there was evidence of aspiration of gastric content during bronchoscopy on admission. Median ProCT values of 1.397 ng/ml (range, 0.372 to 8.358 ng/ml) on admission increased to 2.144 ng/ml (range, 0.716 to 6.910 ng/ml) 24 hours after trauma, and then decreased to baseline values of 1.711 ng/ml (range, 0.611 to 6.639 ng/ml) as early as 36 hours after trauma. In patients without signs of aspiration of gastric content, ProCT values did not exceed 0.418 ng/ml. Non-survivors had higher serum levels of ProCT throughout the study period.

Our findings suggest that ProCT is a useful diagnostic marker for detecting aspiration of gastric content while the prognostic value of ProCT for predicting survival after isolated closed head injury was moderate.