Incidence, Etiology, Timing, and Risk Factors for Clinical Failure in Hospitalized Patients With Community-Acquired Pneumonia

Background: The etiology of clinical failure in hospitalized patients with community-acquired pneumonia (CAP) may be related or unrelated to pulmonary infection. The objective of this study was to define the incidence, etiology, timing, and risk factors associated with clinical failures related to CAP vs those unrelated to CAP. Methods: Observational retrospective study of consecutive CAP patients. All patients who experienced clinical failure were identified. Cases were presented to a review committee that defined, by consensus, etiology, timing, and risk factors for clinical failures related to CAP. Results: Among 500 patients who were enrolled in the study, clinical failure was identified in 67 (13%). Clinical failure was related to CAP in 54 patients (81%). The most common etiologies for clinical failure related to CAP were severe sepsis (33%), acute myocardial infarction (28%), and progressive pneumonia (19%). All cases of severe sepsis occurred in the first 72 h of hospitalization. The most common etiology for clinical failure unrelated to CAP was the development of hospital-acquired pneumonia (45%). At the time of hospital admission, factors associated with clinical failure related to CAP were advanced age, congestive heart failure, hypotension, abnormal gas exchange, acidosis, hypothermia, thrombocytopenia, and pleural effusion. Conclusions: The development of severe sepsis early during hospitalization is the primary etiology for clinical failure related to CAP. To achieve early treatment intervention, physicians should maintain a high index of suspicion for severe sepsis in hospitalized patients with CAP. To decrease the number of clinical failures unrelated to CAP, interventions need to be developed at the local level to improve the processes of care for patients with pneumonia. (CHEST 2008; 134:955-962)