title: Exhaled nitrite/nitrate levels as a marker of respiratory complications after heart valve surgery.
abstract: OBJECTIVE
  The purposes of this study are to measure the nitric oxide metabolites nitrite and nitrate (NOx) in the exhaled breath condensates (EBCs) of patients submitted to heart valve surgery and to assess the correlation between NOx levels and postoperative respiratory complications.
  
  
  METHODS
  Exhaled breath condensate and blood samples were collected from each patient during spontaneous breathing preoperatively, during invasive mechanical ventilation in the fourth hour after surgery and 12, 24, 48, and 72 hours after the operation. Nitrite and nitrate levels in the EBC and serum were measured by chemiluminescence.
  
  
  RESULTS
  Thirty-two patients were included in the study. In patients who presented with postoperative respiratory complications, the postoperative levels of NOx were significantly higher in the EBC from the fourth postoperative hour compared with those who experienced uneventful postoperative periods (P = .027). However, the preoperative and postoperative serum levels of NOx were not significantly different in between-group analyses (P = .995).
  
  
  CONCLUSIONS
  Our results suggest that the postoperative NOx level in the EBC is an early marker of respiratory complications after heart valve surgery. Additional studies using large cohorts are necessary to corroborate our results and to better define the clinical usefulness of assessing NOx in the EBC after cardiac surgery.
authors: Division of Cardiothoracic Surgery, Department of Surgery and Anatomy, School of Medicine of Ribeirão Preto of the University of São Paulo, São Paulo, Brazil.
authors: Lívia
authors: L
authors: Arcêncio
authors: Daniella Alves
authors: DA
authors: Vento
authors: Solange
authors: S
authors: Bassetto
authors: Paulo R B
authors: PR
authors: Evora
authors: Alfredo José
authors: AJ
authors: Rodrigues
mesh_terms: D000704:Analysis of Variance; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism*; D001944:Breath Tests / Q000379:methods*; D006348:Cardiac Surgical Procedures; D045853:Exhalation; D005260:Female; D006351:Heart Valves / Q000601:surgery*; D006801:Humans; D049449:Luminescence; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000032:analysis / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D009573:Nitrites / Q000032:analysis / Q000378:metabolism*; D010092:Oximetry; D011183:Postoperative Complications / Q000378:metabolism*; D011446:Prospective Studies; D012121:Respiration, Artificial; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide
keywords: Cardiopulmonary bypass; Heart valve; Nitric oxide; Surgery