title: Acute respiratory failure in the elderly: etiology, emergency diagnosis and prognosis.
abstract: BACKGROUND
  Our objectives were to determine the causes of acute respiratory failure (ARF) in elderly patients and to assess the accuracy of the initial diagnosis by the emergency physician, and that of the prognosis.
  
  
  METHODS
  In this prospective observational study, patients were included if they were admitted to our emergency department, aged 65 years or more with dyspnea, and fulfilled at least one of the following criteria of ARF: respiratory rate at least 25 minute-1; arterial partial pressure of oxygen (PaO2) 70 mmHg or less, or peripheral oxygen saturation 92% or less in breathing room air; arterial partial pressure of CO2 (PaCO2) > or = 45 mmHg, with pH < or = 7.35. The final diagnoses were determined by an expert panel from the completed medical chart.
  
  
  RESULTS
  A total of 514 patients (aged (mean +/- standard deviation) 80 +/- 9 years) were included. The main causes of ARF were cardiogenic pulmonary edema (43%), community-acquired pneumonia (35%), acute exacerbation of chronic respiratory disease (32%), pulmonary embolism (18%), and acute asthma (3%); 47% had more than two diagnoses. In-hospital mortality was 16%. A missed diagnosis in the emergency department was noted in 101 (20%) patients. The accuracy of the diagnosis of the emergency physician ranged from 0.76 for cardiogenic pulmonary edema to 0.96 for asthma. An inappropriate treatment occurred in 162 (32%) patients, and lead to a higher mortality (25% versus 11%; p < 0.001). In a multivariate analysis, inappropriate initial treatment (odds ratio 2.83, p < 0.002), hypercapnia > 45 mmHg (odds ratio 2.79, p < 0.004), clearance of creatinine < 50 ml minute-1 (odds ratio 2.37, p < 0.013), elevated NT-pro-B-type natriuretic peptide or B-type natriuretic peptide (odds ratio 2.06, p < 0.046), and clinical signs of acute ventilatory failure (odds ratio 1.98, p < 0.047) were predictive of death.
  
  
  CONCLUSIONS
  Inappropriate initial treatment in the emergency room was associated with increased mortality in elderly patients with ARF.
authors.affiliation: Department of Emergency Medicine and Surgery, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Université Pierre et Marie Curie-Paris 6 75651 Paris Cedex 13, France. patrick.ray@psl.ap-hop-paris.fr
authors.forename: Patrick
authors.initials: P
authors.lastname: Ray
authors.forename: Sophie
authors.initials: S
authors.lastname: Birolleau
authors.forename: Yannick
authors.initials: Y
authors.lastname: Lefort
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Becquemin
authors.forename: Catherine
authors.initials: C
authors.lastname: Beigelman
authors.forename: Richard
authors.initials: R
authors.lastname: Isnard
authors.forename: Antonio
authors.initials: A
authors.lastname: Teixeira
authors.forename: Martine
authors.initials: M
authors.lastname: Arthaud
authors.forename: Bruno
authors.initials: B
authors.lastname: Riou
authors.forename: Jacques
authors.initials: J
authors.lastname: Boddaert
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D004632:Emergency Medical Services / Q000379:methods; D004636:Emergency Service, Hospital; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D010820:Physicians; D011379:Prognosis; D011446:Prospective Studies; D011654:Pulmonary Edema / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000628:therapy; D012131:Respiratory Insufficiency / Q000175:diagnosis* / Q000209:etiology* / Q000401:mortality / Q000628:therapy