title: Flush Rate Oxygen for Emergency Airway Preoxygenation.
abstract: Recent data suggest that emergency airway preoxygenation with a bag-valve-mask (BVM) device (held with a tight mask seal but without squeezing the bag) is superior to a nonrebreather (NRB) mask at standard oxygen flow rates. We seek to determine whether preoxygenation with an NRB mask with flush rate oxygen (>40 L/min by fully opening a standard oxygen flowmeter) is noninferior to BVM device with standard-flow oxygen (15 L/min). We also seek to compare the efficacy of preoxygenation with NRB mask at flush rate oxygen with both NRB mask with oxygen at 15 L/min and simple mask at flush rate oxygen.
  
  
  
  We performed a crossover trial using healthy volunteers. In random sequence, subjects underwent 3-minute trials of preoxygenation with nonrebreather mask with oxygen at 15 L/min (NRB-15), nonrebreather mask with flush rate oxygen (NRB-Flush), BVM device with oxygen at 15 L/min (BVM-15), and simple mask with flush rate oxygen. The primary outcome measure was the FeO2in a single exhaled breath. We compared the FeO2of NRB-Flush to other study groups, using a prespecified noninferiority margin of 10%.
  
  
  
  We enrolled 26 subjects. Mean FeO2values for NRB-15, NRB-Flush, BVM-15, and simple mask with flush rate oxygen were 54% (95% confidence interval [CI] 50% to 57%), 86% (95% CI 84% to 88%), 77% (95% CI 74% to 81%), and 72% (95% CI 69% to 76%), respectively. FeO2for NRB-Flush was noninferior to BVM-15 (difference 8%; 95% CI 5% to 11%). FeO2for NRB-Flush was higher than both NRB-15 (FeO2difference 32%; 95% CI 29% to 35%) and simple mask with flush rate oxygen (FeO2difference 13%; 95% CI 10% to 17%).
  
  
  
  Preoxygenation with NRB-Flush was noninferior to BVM-15. NRB with flush rate oxygen may be a reasonable preoxygenation method for spontaneously breathing patients undergoing emergency airway management.
authors: Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, MN. Electronic address: briandriver@gmail.com.
authors: Brian E
authors: BE
authors: Driver
authors: Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, MN; Division of Pulmonary/Critical Care, Department of Medicine, Hennepin County Medical Center, Minneapolis, MN.
authors: Matthew E
authors: ME
authors: Prekker
authors: Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, MN.
authors: Rebecca L
authors: RL
authors: Kornas
authors: Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, MN.
authors: Ellen K
authors: EK
authors: Cales
authors: Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, MN.
authors: Robert F
authors: RF
authors: Reardon
mesh_terms: D000328:Adult; D058109:Airway Management / Q000379:methods*; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006801:Humans; D017214:Laryngeal Masks; D008297:Male; D010100:Oxygen / Q000378:metabolism
chemical_list: D010100:Oxygen