[Hypercapnic and hypoxic ventilatory responses in patients with chronic obstructive pulmonary disease]

In patients with chronic obstructive pulmonary disease (COPD), we examined ventilatory responses to hypercapnia (HCVR) and hypoxia (HVR). HVR was with normal limits, although HCVR was decreased in half of the patients. The patients with COPD often developed oxygen desaturation during sleep. Also, they had severe hypoxemia during exercise. High responders both to HCVR and HVR had no hypoxic episode during sleep or exercise. We conclude that hypoxemia during sleep or exercise may be related to both HCVR and HVR.