Pneumonia presenting with organ dysfunctions: Causative microorganisms, host factors and outcome

Community-acquired pneumonia (CAP) is a serious infection that may occasionally rapidly evolve provoking organ dysfunctions. We aimed to characterize CAP presenting with organ dysfunctions at the emergency room, with regard to host factors and causative microorganisms, and its impact on 30-day mortality. 460 of 4070 (11.3%) CAP patients had ≥2 dysfunctions at diagnosis, with a 30-day mortality of 12.4% vs. 3.4% in those with one or no dysfunctions. Among them, the most frequent causative microorganisms were Streptococcus pneumoniae, gram-negatives and polymicrobial etiology. Independent host risk factors for presenting with ≥2 dysfunctions were: liver (OR 2.97) and renal diseases (OR 3.91), neurological disorders (OR 1.86), and COPD (OR 1.30). Methicillin-resistant Staphylococcus aureus (OR 6.41) and bacteraemic episodes (OR 1.68) had the higher independent risk among microorganisms. The number of organ dysfunctions vs. none increased at 30-day mortality: three organs (OR 11.73), two organs (OR 4.29), and one organ (OR 2.42) whereas Enterobacteria (OR 3.73) were also independently related to mortality. The number of organ dysfunctions was the strongest 30-day mortality risk factor while Enterobacteriaceae was also associated with poorer outcome. The assessment of organ dysfunctions in CAP should be implemented for management, allocation and treatment decisions on initial evaluation.