What is the best management option in a patient with COPD, with low SpO2 at rest?

In COPD, non-uniform ventilation and ventilation-perfusion mismatching leads to localized vasoconstriction Supplemental oxygen abolishes this constriction, leading to improved ventilation/perfusion ratio. High flow oxygen is not tolerated as it leads to crusting, dryness and epistaxis. While continuous therapy is required for patients who show hypoxemia at rest, intermittent treatment during specific periods may be used for patients who demonstrate intermittent hypoxemia.