The High Flow Nasal Cannula Improves the Exercise Capacity in Patients with Chronic Obstructive Pulmonary Disease: Randomized, Crossover Clinical Trial

ABSTRACT

Introduction: The effects of high flow nasal cannula (HFNC) such as reducing of work of breathing could improve exercise tolerance in stable chronic obstructive pulmonary disease (COPD) patients, however there is a great lack of evidence supporting its use. Aims: To compare the maximum speed (MS) reached on an Incremental Exercise Test (IET) and Limit Time (Tlim) on a Constant Work Rate Exercise Test (CWRET) using High Flow Nasal Cannula (HFNC) vs Venturi Mask (VM). Methods Subjects: 28 COPD patients (56% male, age mean 69 yr and FEV1 44% predicted) who require oxygen during exercise. Design: randomized crossover trial. Variables: MS, Tlim, symptoms, oxygen saturation (SpO2), heart rate, respiratory rate, blood pressure and comfort. Procedure: Each patient performed two IET and two CWRET, one time using HFNC and the other with VM. Statistic analysis: we carried out a hypothesis contrast of paired data comparing MS, Tlim and physiological variables. p < 0.05 was considered statistically significant. Results: HFNC vs MV increased MS (5,9 vs 5,7 km/h; p = 0.0002) and Tlim (450 vs 315 sec; p = 0.004), with higher SpO2 and less dyspnea (p < 0.05) at both isowork and isotime, with no statistically significant differences on confort. Conclusions: HFNC improved exercise capacity in COPD patients increasing MS during IET and Tlim on CWRET with higher SpO2 and reduced dyspnea in comparison to VM. HFNC and VM were equally comfortable.