Resolution of clinical and laboratory abnormalities after diagnosis of ventilator-associated pneumonia in trauma patients.

BACKGROUND Guidelines advise that patients with ventilator-associated pneumonia (VAP) should respond clinically by Day 3 of antibiotics. White blood cell (WBC) count, maximum temperature (Tmax), and PaO2:FIO2 ratio are all said to respond significantly by Day 6. Resolution of abnormalities has not been evaluated in trauma patients. METHODS Retrospective review of trauma patients with VAP. The WBC count, Tmax, and PaO2:FIO2 were evaluated for 16 days after diagnosis. Patients were grouped into uncomplicated VAP, complicated VAP (those with inadequate empirical therapy [IEAT], VAP relapse/superinfection, or acute respiratory distress syndrome), and concurrent infection+VAP (those also infected at another site). RESULTS There were 126 patients (uncomplicated VAP=29, complicated VAP=69, and concurrent infection+VAP=28). The mean Tmax in patients with uncomplicated VAP decreased significantly from diagnosis to Day 4 (Day 1: 39 ± 0.5°C vs. Day 4: 38.6 ± 0.7°C; p=0.028) but never normalized. Their WBC counts and PaO2:FIO2 did not change significantly over the 16-day follow-up and never normalized. When comparing the three groups, the probability of resolving all three abnormalities was not different (p=0.5). CONCLUSIONS Clinical and laboratory abnormalities in critically injured patients with VAP do not resolve as quickly as suggested in the guidelines. Future studies should evaluate new methods to determine the response to antibiotic therapy in critically injured patients with VAP.