Prediction of requirement for mechanical ventilation in community-acquired pneumonia with acute respiratory failure: a multicenter prospective study.

BACKGROUND Several severity scoring systems for predicting mortality are established in community-acquired pneumonia (CAP). OBJECTIVES The predictability of the aggravation such as requirement for mechanical ventilation in addition to mortality was examined in CAP patients with acute respiratory failure by using the age, dehydration, respiratory failure, orientation disturbance and blood pressure (A-DROP) scoring system which was proposed by the Japanese Respiratory Society. METHODS This study was a prospective, multicenter, observational cohort study. The severity of pneumonia was examined using A-DROP and Pneumonia Severity Index (PSI) which originated from the Infectious Disease Society of America. Requirement for mechanical ventilation and mortality were evaluated for 28 days. RESULTS 482 CAP patients with acute respiratory failure were enrolled in the study. The 28-day mortality and mechanical ventilation rates were 12.3 and 14.4%, respectively. There were no significant differences in the areas under the receiver-operator characteristic curves for prediction of mortality between A-DROP and PSI (χ² test; p = 0.3613). In the subgroup analyses by severity, the A-DROP scoring system showed a severity-dependent increase of mortality (moderate 5.6%, severe 16.1%, extremely severe 27.1%, Cochran-Armitage trend test; p < 0.0001). Similar results were obtained for mechanical ventilation rate (moderate 9.8%, severe 16.7%, extremely severe 25.4%, Cochran-Armitage trend test; p = 0.0006). The compliance with scoring the A-DROP was higher than that with scoring the PSI (96.9 vs. 71.6%). CONCLUSIONS The results of this study suggest that the A-DROP scoring system could be a simple CAP risk scoring system which could predict not only mortality, but also the requirement for mechanical ventilation.