Time to desaturation less than one minute predicts the need for long-term home oxygen therapy

Respir Care. 2011 Nov;56(11):1812-7. doi: 10.4187/respcare.01164. Epub 2011 May 20.

Abstract

Background: Exercise desaturation in patients with COPD is a pathophysiological phenomenon that is not wholly understood and whose clinical consequences are still unclear.

Methods: Eighty-three patients with moderate to severe COPD and P(aO(2)) > 60 mm Hg who desaturated during the 6-min walk test were followed for 5 years. Forty-eight patients had early desaturation (S(pO(2)) fell below 90% less than one minute after starting the walk test). Spirometry, blood-gas measurements, and 6-min walk tests were performed every 6 months. We recorded 6-min walk distance, baseline S(pO(2)), lowest S(pO(2)), and the time to S(pO(2)) < 90%. In each control, stable patients with severe hypoxia at rest who required long-term oxygen therapy were identified.

Results: Upon completion of the study, 65% of the early desaturators had developed severe hypoxemia and required long-term home oxygen, versus 11% in the non-early desaturators (P < .001).

Conclusions: In patients with moderate to severe COPD, desaturation within the first minute of the 6-min walk test predicts the need for long-term home oxygen at 5-year follow-up.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Exercise Test
  • Female
  • Health Services Needs and Demand
  • Home Care Services, Hospital-Based*
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Oxygen / blood*
  • Oxygen Inhalation Therapy*
  • Pulmonary Disease, Chronic Obstructive / blood*
  • Pulmonary Disease, Chronic Obstructive / mortality
  • Pulmonary Disease, Chronic Obstructive / physiopathology
  • Pulmonary Disease, Chronic Obstructive / therapy*
  • Time Factors

Substances

  • Oxygen