title: The fraction of inspired oxygen in infants receiving oxygen via nasal cannula often exceeds safe levels.
abstract: OBJECTIVE
  Measure the fraction of inspired oxygen (F(IO(2))) in infants receiving supplemental oxygen via nasal cannula and identify clinical variables that affect F(IO(2)).
  
  
  METHODS
  Hypopharyngeal gas samples were obtained from 20 infants receiving oxygen via nasal cannula at flows between 0 and 4 L/min. F(IO(2)) was calculated using the alveolar gas equation and measurements of partial pressure of oxygen in the samples and the barometric pressure.
  
  
  RESULTS
  F(IO(2)) increased as oxygen flow was increased. F(IO(2)) exceeded safe levels (> 60%) in two thirds of samples when the oxygen flow was 2 L/min or higher. Tachypnea (respiratory rate > 40 breaths/min) was associated with lower F(IO(2)).
  
  
  CONCLUSIONS
  Infants receiving oxygen via nasal cannula at > or = 2 L/min may be at risk for hyperoxic lung injury. Therefore, we recommend using the lowest possible oxygen flow needed to maintain normoxia in infants requiring prolonged oxygen therapy via nasal cannula.
authors.affiliation: Division of Critical Care Medicine, Department of Pediatrics, University of Miami School of Medicine/Jackson Memorial Hospital, Miami, Florida 33101-6960, USA. jkuluz@med.miami.edu
authors.forename: J W
authors.initials: JW
authors.lastname: Kuluz
authors.forename: G E
authors.initials: GE
authors.lastname: McLaughlin
authors.forename: B
authors.initials: B
authors.lastname: Gelman
authors.forename: G P
authors.initials: GP
authors.lastname: Cantwell
authors.forename: J
authors.initials: J
authors.lastname: Thomas
authors.forename: T
authors.initials: T
authors.lastname: Mahon
authors.forename: C L
authors.initials: CL
authors.lastname: Schleien
mesh_terms: D006801:Humans; D007223:Infant; D010100:Oxygen / Q000008:administration & dosage*; D010102:Oxygen Inhalation Therapy; D010313:Partial Pressure; D012119:Respiration
chemical_list: D010100:Oxygen