Background:
In spite of oxygen therapy, desaturations frequently occur during exercise in COPD patients. Although current recommendations are to add 1 L/min to the baseline oxygen flow during exertion, a new closed-loop system (FreeO2) automatically and continuously adjusts the oxygen flow to the patient's needs based on the oxygen saturation by pulse oximetry (SpO2), end-tidal CO2 (EtCO2) and respiratory rate. A preliminary study showed significant improvement in exercise tolerance in COPD patients not needing oxygen therapy. Although oxygen flow could be two fold increased during exercise, a worsening hypercapnia is plausible in severe COPD.
Aim of this study is to evaluate this system during endurance shuttle walking test in COPD patients with oxygen therapy and hypercapnia.
Methods: The investigators proposed to conduct a controlled, randomized cross-over study comparing the efficacy of a Closed-loop System for Oxygen Delivery (FreeO2) as compared with fixed oxygen flow during an endurance shuttle walking test in patients with COPD, oxygen therapy and hypercapnia.