title: Usefulness of B-type natriuretic peptide in elderly patients with acute dyspnea.
abstract: OBJECTIVE
  Differentiating cardiogenic pulmonary edema (CPE) from respiratory causes of dyspnea is particularly difficult in elderly patients. The aim of our study was to evaluate B-type natriuretic peptide (BNP) in patients older than 65 years presenting with acute dyspnea.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Medical emergency department of a 2000-bed urban teaching hospital.
  
  
  METHODS
  Patients aged over 65 years presenting with acute dyspnea and a respiratory rate more than 25/min or a PaO(2) below 70 mmHg, SpO(2 )less than 92%, PaCO(2) higher than 45 mmHg with pH less than 7.35, were included. BNP levels, measured blind at admission were compared with the final diagnosis (CPE or no CPE) as defined by experts.
  
  
  METHODS
  None.
  
  
  RESULTS
  Three hundred eight patients (mean age of 80 years) were enrolled in the study. The median BNP was 575 pg/ml [95% confidence interval (CI): 410-898] in the CPE group (n=141) versus 75 pg/ml (95% CI: 59-98) in the no CPE group (n=167) (p<0.001). The best threshold value of BNP was 250 pg/ml, with a sensitivity and specificity for CPE of 0.78 (95% CI: 0.71-0.84) and 0.90 (95% CI: 0.84-0.93), respectively. The area under the ROC curve was 0.874+/-0.081 (p<0.001). The accuracy of BNP-assisted diagnosis was higher than that of the emergency physician (0.84 versus 0.77, p<0.05).
  
  
  CONCLUSIONS
  Analysis of BNP is useful in elderly patients with acute dyspnea, but the threshold value is higher than that previously determined.
authors.affiliation: Department of Emergency Medicine and Surgery, Centre Hospitalo-Universitaire (CHU) Pitié-Salpêtrière Hospital, Assistance-Publique Hôpitaux de Paris (AP-HP), Université Pierre et Marie Curie, 75013 Paris, France. patrick.ray@psl.ap-hop-paris.fr
authors.forename: Patrick
authors.initials: P
authors.lastname: Ray
authors.forename: Martine
authors.initials: M
authors.lastname: Arthaud
authors.forename: Yannick
authors.initials: Y
authors.lastname: Lefort
authors.forename: Sophie
authors.initials: S
authors.lastname: Birolleau
authors.forename: Catherine
authors.initials: C
authors.lastname: Beigelman
authors.forename: Bruno
authors.initials: B
authors.lastname: Riou
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D001784:Blood Gas Analysis; D004417:Dyspnea / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D045283:Natriuretic Agents / Q000097:blood*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D011446:Prospective Studies; D011654:Pulmonary Edema / Q000150:complications / Q000175:diagnosis; D012372:ROC Curve; D012119:Respiration; D012680:Sensitivity and Specificity
chemical_list: D045283:Natriuretic Agents; D020097:Natriuretic Peptide, Brain