Ambulatory oxygen therapy, exercise, and survival with advanced chronic obstructive pulmonary disease (the Nocturnal Oxygen Therapy Trial revisited)

Respir Care. 2000 Feb;45(2):204-11; discussion 211-3.


The NOTT study showed improved survival in COT patients who received LTOT for longer periods (mean 17.7 h/d, median 19.4 h/d) from an ambulatory oxygen system, compared with the survival of NOT patients who received oxygen for a mean of 11.8 h/d from a stationary system. The differences in survival could have been due to the method or the duration of oxygen therapy, or both. An increase in cardiac output and increased oxygenation of the arterial blood (oxygen content) results in increased tissue oxygen transport. In addition, COT was associated with better survival and reduced hospitalizations, compared with NOT patients who were unable to increase their walking level.

MeSH terms

  • Ambulatory Care*
  • Analysis of Variance
  • Clinical Trials as Topic
  • Exercise Tolerance
  • Humans
  • Long-Term Care
  • Lung Diseases, Obstructive / mortality
  • Lung Diseases, Obstructive / physiopathology
  • Lung Diseases, Obstructive / therapy*
  • Oxygen Inhalation Therapy / methods*
  • Proportional Hazards Models
  • Survival Analysis
  • Time Factors
  • Walking / physiology*