title: Predicting success of high-flow nasal cannula in pneumonia patients with hypoxemic respiratory failure: The utility of the ROX index.
abstract: The purpose of the study is to describe early predictors and to develop a prediction tool that accurately identifies the need for mechanical ventilation (MV) in pneumonia patients with hypoxemic acute respiratory failure (ARF) treated with high-flow nasal cannula (HFNC).
  
  
  
  This is a 4-year prospective observational 2-center cohort study including patients with severe pneumonia treated with HFNC. High-flow nasal cannula failure was defined as need for MV. ROX index was defined as the ratio of pulse oximetry/fraction of inspired oxygen to respiratory rate.
  
  
  
  One hundred fifty-seven patients were included, of whom 44 (28.0%) eventually required MV (HFNC failure). After 12 hours of HFNC treatment, the ROX index demonstrated the best prediction accuracy (area under the receiver operating characteristic curve 0.74 [95% confidence interval, 0.64-0.84]; P<.002). The best cutoff point for the ROX index was estimated to be 4.88. In the Cox proportional hazards model, a ROX index greater than or equal to 4.88 measured after 12 hours of HFNC was significantly associated with a lower risk for MV (hazard ratio, 0.273 [95% confidence interval, 0.121-0.618]; P=.002), even after adjusting for potential confounding.
  
  
  
  In patients with ARF and pneumonia, the ROX index can identify patients at low risk for HFNC failure in whom therapy can be continued after 12 hours.
authors.affiliation: Critical Care Department, Vall d'Hebron University Hospital, Vall d'Hebron Research Institute, Barcelona, Spain; Ciber Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain. Electronic address: oroca@vhebron.net.
authors.forename: Oriol
authors.initials: O
authors.lastname: Roca
authors.affiliation: AP-HP, Hôpital Louis Mourier, Service de Réanimation Médico-Chirurgicale, F-92700 Colombes, France; INSERM, IAME, UMR 1137, F-75018 Paris, France; Univ Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, F-75018 Paris, France.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Messika
authors.affiliation: Critical Care Department, Vall d'Hebron University Hospital, Vall d'Hebron Research Institute, Barcelona, Spain; Departament de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spains also been shown.
authors.forename: Berta
authors.initials: B
authors.lastname: Caralt
authors.affiliation: Critical Care Department, Vall d'Hebron University Hospital, Vall d'Hebron Research Institute, Barcelona, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: García-de-Acilu
authors.affiliation: AP-HP, Hôpital Antoine Béclère, Service de Réanimation Polyvalente et Surveillance Continue, F-92140 Clamart, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Sztrymf
authors.affiliation: AP-HP, Hôpital Louis Mourier, Service de Réanimation Médico-Chirurgicale, F-92700 Colombes, France; INSERM, IAME, UMR 1137, F-75018 Paris, France; Univ Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, F-75018 Paris, France.
authors.forename: Jean-Damien
authors.initials: JD
authors.lastname: Ricard
authors.affiliation: Ciber Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain; Critical Care Department, Mar University Hospital, Mar Research Institute (IMIM), Universitat Pompeu Fabra, Barcelona, Spain.
authors.forename: Joan R
authors.initials: JR
authors.lastname: Masclans
mesh_terms: D000328:Adult; D000368:Aged; D002404:Catheterization / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009666:Nose; D010092:Oximetry; D010100:Oxygen / Q000378:metabolism; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011014:Pneumonia / Q000150:complications / Q000628:therapy*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012131:Respiratory Insufficiency / Q000209:etiology / Q000628:therapy*; D056152:Respiratory Rate / Q000502:physiology; D012720:Severity of Illness Index; D017211:Treatment Failure
chemical_list: D010100:Oxygen
keywords: Acute respiratory failure; High flow nasal cannula; Hypoxemia; Nasal high flow; Oxygen therapy; Pneumonia