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Phenotyping community-acquired pneumonia according to the presence of acute respiratory failure and severe sepsis

Stefano Aliberti1, Anna Maria Brambilla2, James D Chalmers3, Catia Cilloniz4, Julio Ramirez5, Angelo Bignamini6, Elena Prina2, Eva Polverino4, Paolo Tarsia7, Alberto Pesci1, Antoni Torres4, Francesco Blasi7* and Roberto Cosentini2

Author Affiliations

1 Clinica Pneumologica, Department of Health Science, University of Milan Bicocca, AO San Gerardo, Via Pergolesi 33, Monza, Italy

2 Emergency Medicine Department, IRCCS Fondazione Ca’ Granda, Ospedale Maggiore Policlinico, Via F. Sforza 35, Milan, Italy

3 Tayside Respiratory Research Group, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, UK

4 Hospital Clínic, IDIBAPS, Ciberes, Barcelona, Spain

5 Division of Infectious Diseases, Department of Medicine, University of Louisville, Louisville, KY, USA

6 School of Specialization in Hospital Pharmacy, University of Milan, Via Colombo, 71, Milan, Italy

7 Department of Pathophysiology and Transplantation, IRCCS Fondazione Ca’ Granda Ospedale Maggiore Policlinico, University of Milan, Via F. Sforza 35, Milan, Italy

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Respiratory Research 2014, 15:27  doi:10.1186/1465-9921-15-27

Published: 4 March 2014



Acute respiratory failure (ARF) and severe sepsis (SS) are possible complications in patients with community-acquired pneumonia (CAP). The aim of the study was to evaluate prevalence, characteristics, risk factors and impact on mortality of hospitalized patients with CAP according to the presence of ARF and SS on admission.


This was a multicenter, observational, prospective study of consecutive CAP patients admitted to three hospitals in Italy, Spain, and Scotland between 2008 and 2010. Three groups of patients were identified: those with neither ARF nor SS (Group A), those with only ARF (Group B) and those with both ARF and SS (Group C) on admission.


Among the 2,145 patients enrolled, 45% belonged to Group A, 36% to Group B and 20% to Group C. Patients in Group C were more severe than patients in Group B. Isolated ARF was correlated with age (p < 0.001), COPD (p < 0.001) and multilobar infiltrates (p < 0.001). The contemporary occurrence of ARF and SS was associated with age (p = 0.002), residency in nursing home (p = 0.007), COPD (p < 0.001), multilobar involvement (p < 0.001) and renal disease (p < 0.001). 4.2% of patients in Group A died, 9.3% in Group B and 26% in Group C, p < 0.001. After adjustment, the presence of only ARF had an OR for in-hospital mortality of 1.85 (p = 0.011) and the presence of both ARF and SS had an OR of 6.32 (p < 0.001).


The identification of ARF and SS on hospital admission can help physicians in classifying CAP patients into three different clinical phenotypes.

Pneumonia; Sepsis; Severe sepsis; Acute respiratory failure; ARDS; CAP; Community-acquired pneumonia; Mortality; Oxygenation