Background: The fraction of inspired oxygen (FiO(2)) during oxygen-driven jet nebulization is unknown. In the case of air-driven jet nebulization, oxygen is often added through a nasal device, and again, the FiO(2) is unknown. The aim of this experimental study was to measure FiO(2) during oxygen- and air-driven jet nebulization, oxygen being added through a nasal device, and to compare the values observed with those measured during standard oxygen therapy.
Methods: An endotracheal tube was inserted into the distal tracheal extremity of a cadaveric head and neck specimen and connected to a pump, simulating different respiratory patterns. FiO(2) was measured using an electrochemical oxygen analyzer under different nebulization and oxygen delivery conditions. Variables were compared using canonical analysis and analysis of simple and multiple variance.
Results: FiO(2) was significantly influenced by the mode of oxygen delivery (p = 0.001). The highest FiO(2) was observed when oxygen was delivered via a nasopharyngeal catheter associated with air-driven jet nebulization. For oxygen flow rates of 12 and 15 L/min, a nasal cannula combined with air-driven jet nebulization resulted in a similar FiO(2). The FiO(2) was significantly lower in the case of oxygen-driven jet nebulization. The FiO(2) decreased with increasing respiratory rate (p < 0.001) and tidal volume (p < 0.001).
Conclusions: Oxygen delivery through a nasal device during air-driven jet nebulization significantly increases the FiO(2), whereas oxygen-driven jet nebulization dramatically decreases FiO(2) compared with standard oxygen therapy.