Prognostic role of clinical and laboratory criteria to identify early ventilator-associated pneumonia in brain injury

BACKGROUND: We investigated the role of the clinical pulmonary infection score (CPIS), serum levels of procalcitonin (PCT), C-reactive protein (CRP), and serum amyloid A (SAA) in the detection of patients with early ventilator-associated pneumonia (VAP). METHODS: Observational study in a university hospital. In 58 patients with severe brain injury receiving mechanical ventilation, CPIS, PCT, CRP and SAA were evaluated at ICU entry and at days 3 to 4 of hospital stay for VAP diagnosis (confirmed by endotracheal aspirate or BAL cultures). RESULTS: We found the following: (1) PCT at entry was increased in patients who later had early VAP develop (25 patients) compared to no VAP (median, 1.4 ng/mL; 25-75 percentiles, 0.14-0.78; vs median, 0.2 ng/mL; 25-75 percentiles, 0.76-2.4, p<0.001; sensitivity, 76%; and specificity, 75%); (2) CPIS increased at the day of VAP diagnosis, compared to entry (median, 6.6+/-1.1 vs 1.5+/-1.1, p<0.001; sensitivity, 97%; specificity, 100%), while other serum inflammatory markers did not change; and (3) deterioration in oxygenation and changes in tracheal secretions were the main determinants of CPIS changes. CONCLUSIONS: PCT may be a useful marker to predict which patients subsequently have early VAP. The CPIS could help as an early way to detect the patients with early VAP and who need further diagnostic testing.