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Long-term oxygen therapy
Qualification is defined by measurement, not by symptoms.
- Qualifying criteria: PaO2 of 55 mm Hg or less, or SpO2 of 88% or less, on room air at rest; or PaO2 of 56–59 mm Hg with cor pulmonale, right heart failure, or a hematocrit above 55%.
- Documented desaturation with exertion or sleep can qualify a patient for oxygen in those settings.
- Continuous oxygen — at least 15 hours per day and ideally 24 — is what improves survival in hypoxemic COPD.
- Qualification must be measured in a stable state, not during an exacerbation, and reassessed afterward.
At the bedside
In chronic hypercapnic COPD, titrate to an SpO2 of 88–92%. Chasing a higher number risks worsening hypercapnia and V/Q mismatch.