title: High levels of B-type natriuretic peptide predict weaning failure from mechanical ventilation in adult patients after cardiac surgery.
abstract: The failure to wean from mechanical ventilation is related to worse outcomes after cardiac surgery. The aim of this study was to evaluate whether the serum level of B-type natriuretic peptide is a predictor of weaning failure from mechanical ventilation after cardiac surgery.
  
  
  
  We conducted a prospective, observational cohort study of 101 patients who underwent on-pump coronary artery bypass grafting. B-type natriuretic peptide was measured postoperatively after intensive care unit admission and at the end of a 60-min spontaneous breathing test. The demographic data, hemodynamic and respiratory parameters, fluid balance, need for vasopressor or inotropic support, and length of the intensive care unit and hospital stays were recorded. Weaning failure was considered as either the inability to sustain spontaneous breathing after 60 min or the need for reintubation within 48 h.
  
  
  
  Of the 101 patients studied, 12 patients failed the weaning trial. There were no differences between the groups in the baseline or intraoperative characteristics, including left ventricular function, EuroSCORE and lengths of the cardiac procedure and cardiopulmonary bypass. The B-type natriuretic peptide levels were significantly higher at intensive care unit admission and at the end of the breathing test in the patients with weaning failure compared with the patients who were successfully weaned. In a multivariate model, a high B-type natriuretic peptide level at the end of a spontaneous breathing trial was the only independent predictor of weaning failure from mechanical ventilation.
  
  
  
  A high B-type natriuretic peptide level is a predictive factor for the failure to wean from mechanical ventilation after cardiac surgery. These findings suggest that optimizing ventricular function should be a goal during the perioperative period.
authors: Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Heart Institute (InCor), Surgical Intensive Care Unit and Department of Anesthesiology, São Paulo/SP, Brazil. thiagomlara@hotmail.com
authors: Thiago Martins
authors: TM
authors: Lara
authors: Ludhmila Abrahao
authors: LA
authors: Hajjar
authors: Juliano Pinheiro
authors: JP
authors: de Almeida
authors: Julia Tizue
authors: JT
authors: Fukushima
authors: Carmem Silvia Valente
authors: CS
authors: Barbas
authors: Adriano Rogerio Baldacin
authors: AR
authors: Rodrigues
authors: Emilia
authors: E
authors: Nozawa
authors: Maria Ignes Zanetti
authors: MI
authors: Feltrim
authors: Elisangela
authors: E
authors: Almeida
authors: Vera
authors: V
authors: Coimbra
authors: Eduardo
authors: E
authors: Osawa
authors: Rafael de Moraes
authors: Rde M
authors: Ianotti
authors: Alcino Costa
authors: AC
authors: Leme
authors: Fabio Biscegli
authors: FB
authors: Jatene
authors: Jose Otavio Costa
authors: JO
authors: Auler
authors: Filomena Regina Barbosa Gomes
authors: FR
authors: Galas
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures; D004812:Epidemiologic Methods; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D011184:Postoperative Period; D011237:Predictive Value of Tests; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012737:Sex Factors; D013997:Time Factors; D017211:Treatment Failure; D015300:Ventilator Weaning; D018754:Ventricular Dysfunction / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain