Figure 3From: Fit for high altitude: are hypoxic challenge tests useful?Idoneità all’alta montagna: i test all’ipossia sono davvero utili?The same copd patient as in figure 2 breathing 2 l/min supplemental nasal O 2 at night. Sleep quality and pulmonary hypertension are improved, arterial hypoxemia is normalized with unchanged hypercapnia. This patient could tolerate a 7 hour flight breathing 4 L/min nasal O2 at rest in a commercial aircraft with a cabin pressure equivalent to an altitude of 2,500 m without additional mechanical ventilatory support.Back to article page