title: High-Flow Nasal Oxygen vs Noninvasive Positive Airway Pressure in Hypoxemic Patients After Cardiothoracic Surgery: A Randomized Clinical Trial.
abstract: OBJECTIVE
  Noninvasive ventilation delivered as bilevel positive airway pressure (BiPAP) is often used to avoid reintubation and improve outcomes of patients with hypoxemia after cardiothoracic surgery. High-flow nasal oxygen therapy is increasingly used to improve oxygenation because of its ease of implementation, tolerance, and clinical effectiveness.
  
  
  OBJECTIVE
  To determine whether high-flow nasal oxygen therapy was not inferior to BiPAP for preventing or resolving acute respiratory failure after cardiothoracic surgery.
  
  
  METHODS
  Multicenter, randomized, noninferiority trial (BiPOP Study) conducted between June 15, 2011, and January 15, 2014, at 6 French intensive care units.
  
  
  METHODS
  A total of 830 patients who had undergone cardiothoracic surgery, of which coronary artery bypass, valvular repair, and pulmonary thromboendarterectomy were the most common, were included when they developed acute respiratory failure (failure of a spontaneous breathing trial or successful breathing trial but failed extubation) or were deemed at risk for respiratory failure after extubation due to preexisting risk factors.
  
  
  METHODS
  Patients were randomly assigned to receive high-flow nasal oxygen therapy delivered continuously through a nasal cannula (flow, 50 L/min; fraction of inspired oxygen [FiO2], 50%) (n = 414) or BiPAP delivered with a full-face mask for at least 4 hours per day (pressure support level, 8 cm H2O; positive end-expiratory pressure, 4 cm H2O; FiO2, 50%) (n = 416).
  
  
  METHODS
  The primary outcome was treatment failure, defined as reintubation, switch to the other study treatment, or premature treatment discontinuation (patient request or adverse effects, including gastric distention). Noninferiority of high-flow nasal oxygen therapy would be demonstrated if the lower boundary of the 95% CI were less than 9%. Secondary outcomes included mortality during intensive care unit stay, changes in respiratory variables, and respiratory complications.
  
  
  RESULTS
  High-flow nasal oxygen therapy was not inferior to BiPAP: the treatment failed in 87 of 414 patients with high-flow nasal oxygen therapy (21.0%) and 91 of 416 patients with BiPAP (21.9%) (absolute difference, 0.9%; 95% CI, -4.9% to 6.6%; P = .003). No significant differences were found for intensive care unit mortality (23 patients with BiPAP [5.5%] and 28 with high-flow nasal oxygen therapy [6.8%]; P = .66) (absolute difference, 1.2% [95% CI, -2.3% to 4.8%]. Skin breakdown was significantly more common with BiPAP after 24 hours (10% vs 3%; 95% CI, 7.3%-13.4% vs 1.8%-5.6%; P < .001).
  
  
  CONCLUSIONS
  Among cardiothoracic surgery patients with or at risk for respiratory failure, the use of high-flow nasal oxygen therapy compared with intermittent BiPAP did not result in a worse rate of treatment failure. The findings support the use of high-flow nasal oxygen therapy in similar patients.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT01458444.
authors.affiliation: Service de Réanimation Adulte, Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France.
authors.forename: François
authors.initials: F
authors.lastname: Stéphan
authors.affiliation: Département d'Anesthésie-Réanimation, Centre Hospitalier Universitaire, Besançon, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Barrucand
authors.affiliation: Département d'Anesthésie-Réanimation, Centre Hospitalier Universitaire, Besançon, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Petit
authors.affiliation: Service de Réanimation Adulte, Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France.
authors.forename: Saida
authors.initials: S
authors.lastname: Rézaiguia-Delclaux
authors.affiliation: Département d'Anesthésie-Réanimation, Centre Hospitalier Universitaire, Clermont Ferrand, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Médard
authors.affiliation: Département d'Anesthésie-Réanimation Centre Hospitalier Universitaire, Lyon, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Delannoy
authors.affiliation: Département d'Anesthésie-Réanimation, Centre Hospitalier Universitaire, Clermont Ferrand, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Cosserant
authors.affiliation: Département d'Anesthésie-Réanimation, Centre Hospitalier Universitaire, Besançon, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Flicoteaux
authors.affiliation: Service de Réanimation Adulte, Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Imbert
authors.affiliation: Service de Réanimation Adulte, Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Pilorge
authors.affiliation: Hôpital St Antoine, Plateforme de recherche Clinique de l'Est Parisien, Paris, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Bérard
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000628:therapy*; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation / Q000379:methods*; D011175:Positive-Pressure Respiration; D011183:Postoperative Complications / Q000628:therapy*; D012131:Respiratory Insufficiency / Q000150:complications / Q000628:therapy*; D019616:Thoracic Surgical Procedures