Automated O 2 titration improves exercise capacity in patients with hypercapnic chronic obstructive pulmonary disease: a randomised controlled cross-over trial

Automatically titrated O 2 flows (FreeO 2 ) was compared with constant O 2 flow on exercise capacity, O 2 saturation and risk of hyperoxia-related hypercapnia in patients with severe COPD with baseline hypercapnia and long-term oxygen therapy (LTOT). Twelve patients were enrolled in a randomised double-blind cross-over study to perform exercise with either FreeO 2 or constant flow. Endurance time (primary outcome) and SpO 2 were both significantly improved with FreeO 2 compared with constant flow (p