title: Dyspnea management in alpha-1 antitrypsin deficiency: effect of oxygen administration.
abstract: BACKGROUND
  A deficiency of alpha-1 antitrypsin (AAT) can lead to pulmonary disease in middle-aged adults in whom dyspnea management can be a significant issue.
  
  
  OBJECTIVE
  The research addressed whether short-term oxygen (O2) administration during activities might decrease dyspnea and improve exercise performance in nonhypoxemic patients with emphysema caused by a deficiency of alpha-1 antitrypsin.
  
  
  METHODS
  This was a double-blind, randomized crossover study of 31 subjects with a deficiency of AAT (mean + SD, age = 47 +/- 7), moderate emphysema and a resting PaO2 > 70 mm Hg. Oxygen saturation (SpO2), 6-minute walk distance, and end of walk dyspnea were measured during three practice walks and during walks with nasal cannula administration of O2 (intervention) and compressed air (control).
  
  
  RESULTS
  Repeated measures analysis of variance (ANOVA) showed significant differences across the walks for SpO (F= 18.9, p = 0.0001), 6-minute walk distance (F= 6.07, p = 0.004), and dyspnea (F= 4.44, p = 0.016). Using post hoc contrasts, SpO2 was the only variable that differed between 20, and compressed air (p < 0.0001). There was, however, an interaction effect of gender with O2 for dyspnea (F= 9.85, p = 0.004). Mean values showed that men did not benefit from O2 (p = 0.87). However, women experienced less dyspnea when receiving O2 as compared with compressed air (p = 0.0025), and although not statistically significant, the lower dyspnea with O2 corresponded with an increased walk distance of 79 feet.
  
  
  CONCLUSIONS
  O2 administration may be useful for reducing dyspnea during exercise in selected populations.
authors.affiliation: National Institute of Nursing Research, National Institutes of Health, Clinical Center Nursing Department, Bethesda, Maryland 20892-2178, USA. aknebel@nih.gov
authors.forename: A R
authors.initials: AR
authors.lastname: Knebel
authors.forename: E
authors.initials: E
authors.lastname: Bentz
authors.forename: P
authors.initials: P
authors.lastname: Barnes
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004417:Dyspnea / Q000145:classification / Q000209:etiology* / Q000628:therapy*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010102:Oxygen Inhalation Therapy; D010147:Pain Measurement; D016138:Walking; D019896:alpha 1-Antitrypsin Deficiency / Q000150:complications*