title: Effect of low flow and high flow oxygen delivery on exercise tolerance and sensation of dyspnea. A study comparing the transtracheal catheter and nasal prongs.
abstract: OBJECTIVE
  We hypothesized that high flow transtracheal oxygen (HFTTO) will improve exercise tolerance as compared with low flow transtracheal oxygen (LFTTO) and that transtracheal oxygen (TTO) will increase exercise tolerance with less dyspnea as compared with nasal prongs (NP) at equivalent oxygen saturation (SaO2).
  
  
  METHODS
  Ten subjects, six male and four female, who were already receiving TTO were recruited for the study.
  
  
  METHODS
  Each subject underwent a total of four modified progressive treadmill tests in a single-blind randomized fashion on two separate days. Two tests were performed with the patients receiving LFTTO and HFTTO while the other two were performed with low- and high-flow oxygen by NP. The flows were adjusted to provide equivalent oxygen saturations at rest for respective groups.
  
  
  RESULTS
  The mean +/- SD exercise distance with HFTTO (1,134 +/- 631 ft) was 2.5 times greater than with LFTTO (446 +/- 328 ft; p < 0.006); and high-flow NP (HFNP [1207 +/- 763 ft]) was 2.38 times greater than with low-flow NP (LFNP[492 +/- 487 ft; p < 0.005]). There was no significant difference in exercise distance and dyspnea scores with HFTTO as compared with HFNP and LFTTO versus LFNP.
  
  
  CONCLUSIONS
  We conclude that the use of high-flow oxygen via both transtracheal catheter and NP significantly increased exercise tolerance in our COPD patients when compared to low-flow oxygen. Transtracheal oxygen did not increase maximum exercise tolerance with less dyspnea as compared with oxygen via NP at equivalent SaO2.
authors.affiliation: Department of Medicine, Creighton University, Omaha, Neb.
authors.forename: N A
authors.initials: NA
authors.lastname: Dewan
authors.forename: C W
authors.initials: CW
authors.lastname: Bell
mesh_terms: D000368:Aged; D004417:Dyspnea / Q000503:physiopathology / Q000628:therapy*; D017079:Exercise Tolerance; D005260:Female; D005541:Forced Expiratory Volume; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation / Q000379:methods*; D012677:Sensation; D016037:Single-Blind Method; D014797:Vital Capacity