Effect of flow and cannula size on generated pressure during nasal high flow

Abstract

Nasal high flow (NHF) with supplemental oxygen has been proposed to treat COVID-19 patients with acute respiratory failure (ARF) [ 1 ]. NHF gained its popularity due to the high oxygenation efficiency and success in treating patients with hypoxemic ARF [ 2 ]. Apart from the delivery of oxygen, NHF reduces the rebreathing from anatomical dead space and generates positive airway pressure; however, the delivered pressure is difficult to quantify due to the unsealed cannula interface. The purpose of this research is to provide clinicians with the indicative data of the generated pressure using different flow settings and cannula sizes.