Continuous Oxygen Therapy

Continuous oxygen therapy (COT) has become widely accepted in the last 20 years in patients with continuous hypoxemia.


COT has been shown to significantly improve survival in hypoxemic patients with chronic obstructive pulmonary disease (COPD).


The benefits of oxygen therapy are best established for patients with severe disease associated with resting hypoxemia.. The Medical Research Council examined the impact of at least 15 hours per day of oxygen in 87 COPD subjects with a resting PaO2 between 40 to 60 mmHg in the stable state. Survival was better with oxygen utilization compared to no oxygen.


COT has been shown to reduce hospitalizations and lengths of stay.


The mechanisms for this improved survival remain elusive. Limited data suggest that LTOT may ameliorate pulmonary vasculopathy, at least during intermediate follow-up.




The role of oxygen therapy in COPD patients experiencing nocturnal desaturation also remains controversial. A meta-analysis of small, randomized controlled trials did not support a mortality benefit (OR 0.97, 95 percent CI 0.41, 2.31)



 Laboratory indications: Documented hypoxemia in adults, children, and infants older than 28 days as evidenced by 
[1] PaO ≤ 55 mm Hg or SaO2 ≤ 88% in subjects breathing room air 


[2] PaO2 of 56-59 mm Hg or SaO2or SpO2 ≤ 89% in association with specific clinical conditions (eg, cor pulmonale, congestive heart failure, or erythrocythemia with hematocrit >56).


Some patients may not demonstrate a need for oxygen therapy at rest (normoxic) but will be hypoxemic during ambulation, sleep, or exercise. Oxygen therapy is indicated during these specific activities when the SaO2 is demonstrated to fall to ≤ 88%.


Patients who are approaching the end of life frequently exhibit dyspnea with or without hypoxemia.
Dyspnea in the absence of hypoxemia can be treated with techniques and drugs other than oxygen.
Oxygen may be tried in these patients at 1-3 liters per minute, to obtain subjective relief of dyspnea.


Continuous Oxygen can be used in  cases were strong evidence may be lacking such as (eg, cluster headaches).


Report of the Medical Research Council Working Party, Long term domiciliary oxygen therapy in chronic hypoxic cor pulmonale complicating chronic bronchitis and emphysema. Lancet. 1981;1(8222):681-6.


 Stoller, J, et al. Oxygen therapy for patients with COPD. Current evidence and the Long-Term Oxygen Treatment Trial. Chest. 2010;138:179-87.