Impact of Automatic Oxygen Titration Alone or with High Flows on Exercise Tolerance in Patients with Lung Disease and Exercise Oxygen Desaturation

Introduction: This study assesses the effects of automated oxygen titration, alone or with high flows on dyspnea and exercise tolerance in patients with chronic lung disease and exercise-induced O2 desaturation. Methods: Patients with chronic lung diseases and exercise desaturation were involved in a 3 treatment arm cross-over study to perform a 3-min constant speed walk test (3min CSST) and an endurance shuttle walking test (ESWT) carried out with one of the 3 oxygen delivery systems: (1) O2 at fixed-flow of 2 L/min (2) or with an automated O2 titration system (FreeO2®) targeting 94% SpO2, and (3) FreeO2 in + high flow nasal cannula (FreeO2 + Airvo®). The main outcome was the dyspnea score (modified Borg scale) following 3min CSST. Secondary outcomes were endurance time and mean/nadir SpO2 during ESWT. Results: In this interim analysis, 14 patients (7 COPD and 4 ILD, 2 PH and 1 CF) were included. There was no difference in the dyspnea score. Endurance time was longer (p<0.001) while mean and nadir SpO2 were higher (p<0.001) with FreeO2 vs fixed-flow O2. There was no further benefit of adding AirvoTM to FreeO2 on endurance time or SpO2. Conclusion: These preliminary results suggest that, despite no improvement in dyspnea, automatic O2 titration increases endurance time and SpO2 during ESWT compared to fixed-flow O2. Adding AirvoTM had no further benefits.