title: Hypoxemia adds to the CURB-65 pneumonia severity score in hospitalized patients with mild pneumonia.
abstract: BACKGROUND
  Hypoxemia may influence the prognosis of patients with mild pneumonia, regardless of the initial CURB-65 score (confusion, blood urea nitrogen > 20 mg/dL, respiratory rate > 30 breaths/min, blood pressure < 90/60 mm Hg, and age ≥ 65 y).
  
  
  OBJECTIVE
  To determine the risk factors associated with hypoxemia and the influence of hypoxemia on clinical outcomes in hospitalized patients with mild pneumonia.
  
  
  METHODS
  We performed a multicenter prospective cohort study of 585 consecutive hospitalized patients with mild pneumonia (CURB-65 groups 0 and 1). We stratified the patients according to the presence of hypoxemia, defined as a P(aO(2))/F(IO(2)) < 300 mm Hg on admission. We assessed the risk factors associated with hypoxemia, hypoxemia's influence on the course of pneumonia, and clinical outcomes (mortality, hospital stay, and need for intensive care unit admission), with multivariable regression.
  
  
  RESULTS
  Fifty percent of the patients (294 cases) had hypoxemia on admission. The risk factors independently associated with hypoxemia were: bilateral radiological involvement (odds ratio 2.8, 95% CI 1.1-7.5), history of COPD (odds ratio 2.5, 95% CI 1.4-4.3), and hypoalbuminemia (odds ratio 2.0, 95% CI 1.1-3.5). The hypoxemic patients had longer hospital stay, higher intensive care unit admission rate, higher rate of severe sepsis, and higher mortality than the non-hypoxemic patients.
  
  
  CONCLUSIONS
  Hypoxemia in patients with mild pneumonia is independently associated with several adverse clinical and radiological variables, and the hypoxemic patients had worse clinical outcomes than the non-hypoxemic patients. Therefore, additional attention should be paid to the presence of hypoxemia, regardless of a low CURB-65 score.
authors.affiliation: Servicio de Neumología. Consorci Hospital General, Universitari de Valencia, Spain. sanz_fraher@gva.es
authors.forename: Francisco
authors.initials: F
authors.lastname: Sanz
authors.forename: Marcos I
authors.initials: MI
authors.lastname: Restrepo
authors.forename: Estrella
authors.initials: E
authors.lastname: Fernández
authors.forename: Eric M
authors.initials: EM
authors.lastname: Mortensen
authors.forename: María Carmen
authors.initials: MC
authors.lastname: Aguar
authors.forename: Angela
authors.initials: A
authors.lastname: Cervera
authors.forename: Eusebi
authors.initials: E
authors.lastname: Chiner
authors.forename: Jose
authors.initials: J
authors.lastname: Blanquer
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D001806:Blood Urea Nitrogen; D003221:Confusion / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D000860:Hypoxia / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D007297:Inpatients; D007362:Intensive Care Units; D008297:Male; D011014:Pneumonia / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D011379:Prognosis; D011446:Prospective Studies; D015656:Respiratory Mechanics / Q000502:physiology*; D012307:Risk Factors; D012720:Severity of Illness Index