Nasal cannula oxygen therapy is a common treatment option for patients with respiratory failure but needs further investigation to understand its potential for use for assisted breathing. Air with a high oxygen level is introduced into the nasal cavity using a nasal cannula during assisted breathing via oxygen therapy. The treatment impacts the nasal airflow dynamics and air-conditioning function. This study aims to investigate the nasal heat and mass transfer and sinus ventilation during assisted breathing at different operating conditions using computational fluid dynamics simulations. The nasal geometry was reconstructed from high-resolution computed tomography scans of a healthy subject. A constant inhalation flow rate of 15 LPM (liters per minute) was used, and the nasal cannula flow rate was set to between 5 and 15 LPM. The results demonstrated that assisted breathing at a high flow rate impacted sinus ventilation. It also changed the mucosal surface heat and mass transfer, thus inhaled air temperature and humidity. The high flow assisted breathing at 36 °C affected the nasal heat flux the most compared with other breathing conditions, while the low flow assisted breathing had minimal effect and, therefore, could be considered ineffective for any relevant treatment.
|Number of pages||11|
|Journal||Physics of Fluids|
|Publication status||Published - 23 May 2022|