title: Phenotyping community-acquired pneumonia according to the presence of acute respiratory failure and severe sepsis.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  The identification of ARF and SS on hospital admission can help physicians in classifying CAP patients into three different clinical phenotypes.
authors.forename: Stefano
authors.initials: S
authors.lastname: Aliberti
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Brambilla
authors.forename: James D
authors.initials: JD
authors.lastname: Chalmers
authors.forename: Catia
authors.initials: C
authors.lastname: Cilloniz
authors.forename: Julio
authors.initials: J
authors.lastname: Ramirez
authors.forename: Angelo
authors.initials: A
authors.lastname: Bignamini
authors.forename: Elena
authors.initials: E
authors.lastname: Prina
authors.forename: Eva
authors.initials: E
authors.lastname: Polverino
authors.forename: Paolo
authors.initials: P
authors.lastname: Tarsia
authors.forename: Alberto
authors.initials: A
authors.lastname: Pesci
authors.forename: Antoni
authors.initials: A
authors.lastname: Torres
authors.affiliation: Department of Pathophysiology and Transplantation, IRCCS Fondazione Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Via F, Sforza 35, Milan, Italy. francesco.blasi@unimi.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Blasi
authors.forename: Roberto
authors.initials: R
authors.lastname: Cosentini
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000235:genetics / Q000401:mortality; D005260:Female; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011014:Pneumonia / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality; D012307:Risk Factors; D018805:Sepsis / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality