Validation of predictors of adverse outcomes in hospital-acquired pneumonia in the ICU.

Objective: To validate a set of predictors of adverse outcomes in patients with ICU-acquired pneumonia in relation to clinically relevant assessment at 28 days.
Design: Prospective, observational study.
Setting: Six medical and surgical ICUs of a university hospital.
Patients: Three hundred thirty-five patients with ICU-acquired pneumonia.
Interventions: None.
Measurements and Main Results: Development of predictors of adverse outcomes was defined when at least one of the following criteria was present at an evaluation made 72-96 hours after starting treatment: no improvement of PaO2/FIO2, need for intubation due to pneumonia, persistence of fever or hypothermia with purulent respiratory secretions, greater than or equal to 50% increase in radiographic infiltrates, or occurrence of septic shock or multiple organ dysfunction syndrome. We also assessed the inflammatory response by different serum biomarkers. The presence of predictors of adverse outcomes was related to mortality and ventilator-free days at day 28. Sequential Organ Failure Assessment score was evaluated and related to mortality at day 28.One hundred eighty-four (55%) patients had at least one predictor of adverse outcomes. The 28-day mortality was higher for those with versus those without predictors of adverse outcomes (45% vs 19%, p<0.001), and ventilator-free days were lower (median [interquartile range], 0 [0-17] vs 22 [0-28]) for patients with versus patients without predictors of adverse outcomes (p<0.001). The lack of improvement of PaO2/FIO2 and lack of improvement in Sequential Organ Failure Assessment score from day 1 to day 5 were independently associated with 28-day mortality and fewer ventilator-free days. The marginal structural analysis showed an odds ratio of death 2.042 (95% CI, 1.01-4.13; p=0.047) in patients with predictors of adverse outcomes. Patients with predictors of adverse outcomes had higher serum inflammatory response accordingly to biomarkers evaluated.
Conclusions: The presence of any predictors of adverse outcomes was associated with mortality and decreased ventilator-free days at day 28. The lack of improvement in the PaO2/FIO2 and Sequential Organ Failure Assessment score was independently associated with mortality in the multivariate analysis.