Chest
Clinical InvestigationsEfficacy of a Pulsed Oxygen Delivery Device during Exercise in Patients with Chronic Respiratory Disease
Section snippets
COS-5
The COS-5 device is an intermittent flow oxygen delivery device which can be used with both stationary and portable liquid oxygen systems as well as oxygen cylinders. The direction of the patient's respiratory flow is sensed via a standard nasal cannula, and the onset of inspiratory flow triggers a pulse of oxygen for a calculated period of time. The volume of oxygen delivered over a minute is approximately 40 percent of that which would be delivered during continuous oxygen delivery at the
RESULTS
The COS-5 was well tolerated by all patients, and they noted little difference from continuous flow delivery during exercise.
Figure 1 and Table 2 compare the arterial oxygen tensions achieved during continuous oxygen delivery and during demand delivery by the COS-5, at differing oxygen flow rates in patients with COPD (Fig 1 upper), and IPF (Fig 1 lower). As can be seen, there was an excellent correlation in PaO2 at equivalent flow settings while receiving continuous or COS-5 delivery of oxygen
DISCUSSION
Previous studies of pulsed demand oxygen delivery systems have reported equivalent oxygenation at rest in patients with pulmonary disease when oxygen is delivered by pulsed and continuous modes.12, 13, 14, 15, 16 However, since ambulation is essential for all patients with chronic pulmonary disease, it is important to ensure that these devices provide adequate oxygenation during exercise. We have previously found that the level of oxygenation achieved during exercise by another demand system
REFERENCES (17)
Long-term home oxygen therapy
Chest
(1985)- et al.
A new pendant storage oxygen conserving nasal cannula
Chest
(1985) - et al.
Conservation of oxygen supply using a reservoir nasal cannula in hypoxemic patients at rest and during exercise
Chest
(1985) - et al.
Inspiration-phased oxygen delivery
Lancet
(1984) - et al.
A demand valve conserves oxygen in subjects with chronic obstructive pulmonary disease
Chest
(1984) - et al.
Performance of a demand oxygen saver system during rest, exercise and sleep in hypoxemic patients
Chest
(1988) - et al.
Low concentration oxygen therapy via a demand oxygen delivery system
Chest
(1985) Who needs home oxygen?
(Editorial) Am Rev Respir Dis
(1985)