A novel Venturi system to generate high flow with titratable FiO2

Abstract

Venturi-based flow generators are commonly used for noninvasive continuous positive airway pressure (CPAP) of high-flow nasal oxygen (HFNO). The system is simple and allows to increase the total flow while decreasing the FiO2 starting from a single oxygen source. In this report we describe the characteristics and performance of a novel Venturi system (EasyVEE, Levate, BG, Italy), which allows to vary the size of the port through which ambient air is entrained, hence allowing a continuous modulation of FiO2. The system allowed to modify FiO2 continuously between 35% and 80% and, consequently, a 1.5- to 4.5-fold increase of the total flow rate. A minimal decrease in entrainment performance was observed for positive end-expiratory pressure levels above 12.5 cmH2O. EasyVEE system appears to be a simple, flexible, and reliable solution to generate continuous flow for noninvasive respiratory support interfaces.