title: B-type natriuretic peptides for prediction and diagnosis of weaning failure from cardiac origin.
abstract: OBJECTIVE
  To evaluate and compare BNP and NT-proBNP concentrations to predict weaning failure from mechanical ventilation (MV) due to heart failure (HF) before a spontaneous breathing trial (SBT) and to identify HF as the cause of failure.
  
  
  METHODS
  Prospective, observational study in a university hospital. The sample included 100 patients on MV for over 48 h who underwent an SBT. Echocardiography and sampling for natriuretic peptides were performed immediately before and at the end of SBT. HF was diagnosed by pulmonary artery occlusion pressure >18 mm Hg or signs of elevated filling pressures in echocardiography.
  
  
  RESULTS
  Thirty-two patients failed the SBT, 12 due to HF and 20 due to respiratory failure (RF). Before SBT, BNP and NT-proBNP were higher in patients failing due to HF than RF or in successfully weaned patients. Cut-off values using ROC curve analyses to predict HF were 263 ng/L for BNP (p < 0.001) and 1,343 ng/L for NT-proBNP (p = 0.08). BNP and NT-proBNP increased significantly during SBT in patients failing due to HF. Increases in BNP and NT-proBNP of 48 and 21 ng/L, respectively, showed a diagnostic accuracy for HF of 88.9 and 83.3% (p < 0.001). BNP performed better than NT-proBNP for HF prediction (p = 0.01) and diagnosis (p = 0.009).
  
  
  CONCLUSIONS
  B-type natriuretic peptides, particularly BNP, can predict weaning failure due to HF before an SBT; increases in natriuretic peptides during SBT are diagnostic of HF as the cause of weaning failure. BNP performs better than NT-proBNP in prediction and diagnosis of HF.
authors.affiliation: Intensive Care Department, Institut d'Investigacions Biomédiques, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Lluís
authors.initials: L
authors.lastname: Zapata
authors.forename: Paula
authors.initials: P
authors.lastname: Vera
authors.forename: Antoni
authors.initials: A
authors.lastname: Roglan
authors.forename: Ignasi
authors.initials: I
authors.lastname: Gich
authors.forename: Jordi
authors.initials: J
authors.lastname: Ordonez-Llanos
authors.forename: Antoni J
authors.initials: AJ
authors.lastname: Betbesé
mesh_terms: D000368:Aged; D005260:Female; D006333:Heart Failure / Q000150:complications* / Q000175:diagnosis; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D045283:Natriuretic Agents / Q000097:blood*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011446:Prospective Studies; D012372:ROC Curve; D012131:Respiratory Insufficiency / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology* / Q000628:therapy; D015656:Respiratory Mechanics / Q000502:physiology; D013030:Spain; D014463:Ultrasonography; D015300:Ventilator Weaning / Q000592:standards*
chemical_list: D045283:Natriuretic Agents; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain