Nasal High Flow Oxygen Increases Exercise Tolerance in ILD Patients: Study

Interstitial lung disease (ILD) is an umbrella term used for a large group of diseases that cause scarring (fibrosis) of the lungs. The scarring causes stiffness in the lungs which makes it difficult to breathe and get oxygen to the bloodstream. Lung damage from ILDs is often irreversible and gets worse over time. It is a rare condition and may be caused due to long term exposure to hazardous substances.

High Nasal Flow Oxygen Therapy (HNFOT) provides an anatomical oxygen reservoir within the nasopharynx and oropharynx, by virtue of a CO₂ washout effect due to high oxygen flow. This reduces dead space and in turn, work of breathing. "The method was previously proven efficient in COPD patients and could be implemented during exercise training in ILD patients," according to Yara Al Chikhanie, PhD, from the Dieulefit Santé Cardiopulmonary Rehabilitation Centre in Rhône-Alpes, France, and Samuel Verges, PhD, senior scientist at UM Sports Pathologies at Hôpital Sud in Grenoble, France.

With this background, Yara Al Chikhanie and her team of investigators carried out a study to examine the effect of nasal high flow on exercise tolerance in ILD patients.

Twenty-five patients (10 female) with severe ILD performed three constant-load (70% maximal workload) cycling tests to exhaustion under different breathing conditions: room air, oxygen supplementation (4 L min⁻¹ O₂) and NHF (inspiratory O₂ fraction 0.5, 30–50 L min⁻¹, heated 34 °C and humidified).

Endurance time was significantly longer with NHF (618 ± 297 s) compared to O₂ (369 ± 217 s, p < 0.001) and room air (171 ± 76 s, p < 0.001). Kinetics of oxygen desaturation, chronotropic response, dyspnoea and leg fatigue sensations were delayed with NHF. At exhaustion with NHF, compared to the two other conditions, oxygen desaturation was less severe while heart rate, dyspnoea and leg fatigue were similar.

"NHF significantly improved endurance time, physiological parameters and sensations during exercise in severe ILD patients. NHF may be useful to improve functional capacities and facilitate pulmonary rehabilitation in ILD," the investigators concluded.

Reference:

Study titled, "The effect of heated, humidified nasal high flow oxygen supply on the exercise tolerance in patients with interstitial lung disease: A pilot study," published in Respiratory Medicine.

DOI: https://doi.org/10.1016/j.rmed.2021.106523