High Flow Oxygen Therapy Effect on Healthy Subjects

Impact of High Flow Oxygen Therapy on Diaphragm Thickening Fraction in Healthy Subjects. A Prospective Cohort Study

The use of high-flow nasal cannula (HFNC) has increased. Diaphragmatic ultrasonography is a tool that, as a noninvasive complement to esophageal pressure (Pes) measurement, allows the evaluation of diaphragm function and reflects, through the diaphragm thickening fraction (DTf), the magnitude of diaphragmatic fiber recruitment. The objective of this study was to evaluate the impact of HFNC therapy on the DTf in healthy subjects. Second, this study aimed to assess the behavior of the respiratory rate (RR) and the work of breathing in these subjects.

Inclusion Criteria:

• healthy subjects over 18 years old

Exclusion Criteria:

• contraindication for esophageal balloon placement
• diagnosis of lung disease
• smokers