A new oxygen cannula system using intermittent-demand nasal flow

Chest. 1978 Jul;74(1):39-44. doi: 10.1378/chest.74.1.39.


A new cannula with a system of intermittent nasal flow was evaluated and compared with a standard constant-flow nasal cannula in 15 patients with chronic obstructive pulmonary disease. The intermittent-demand cannula released oxygen only when a negative pressure was detected in the nose (negative mode) or when a a positive pressure ceased to be detected in the nose (positive mode). At rates of flow varying from 0.63 to 5.60 L/min, the continuous-flow mode used 9 percent more oxygen than the negative mode and 31 percent more oxygen than the positive mode to achieve comparable improvement in arterial oxygen tension. The system using the intermittent-demand cannula was sensitive and reliable in over 150 hours of testing.

MeSH terms

  • Adult
  • Aged
  • Carbon Dioxide / blood
  • Female
  • Humans
  • Lung Diseases, Obstructive / blood
  • Lung Diseases, Obstructive / therapy*
  • Male
  • Middle Aged
  • Oxygen / blood
  • Oxygen Inhalation Therapy / economics
  • Oxygen Inhalation Therapy / instrumentation*


  • Carbon Dioxide
  • Oxygen