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

Automatically titrated O flows (FreeO ) was compared with constant O flow on exercise capacity, O 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 or constant flow. Endurance time (primary outcome) and SpO were both significantly improved with FreeO compared with constant flow (p