Cadaveric Study on the Safety of High-Flow Nasal Oxygen in Laser Microlaryngeal Surgery

High-flow nasal oxygen (HFNO), or transnasal humidified rapid-insufflation ventilatory exchange (THRIVE), is a technique providing apneic oxygenation and a degree of ventilation during microlaryngeal surgery. Its use with laser has been questioned due to concern for airway fire. For fire to occur, a triad of ignition source, oxidizer, and fuel source must be present. By using HFNO and eliminating an endotracheal tube (fuel source), it is hypothesized that airway fire risk is minimal. We tested this theory with human cadavers using HFNO with increasing levels of FiO₂ while performing microlaryngeal laser surgery.

HFNO was placed on two cadavers, and oxygen was administered at incrementally increasing fraction of inspired oxygen (FiO₂) concentrations (30%-100%). Laryngeal microsurgery was conducted with CO₂ and KTP lasers applied for 30 s. Oxygen readings were taken at several anatomic locations along the body assessing oxygen concentrations in correlation with increasing FiO₂ administration.

The use of CO₂ and KTP laser on cadaveric vocal folds produced char but no spark or airway fire at any of the tested oxygen concentrations. Apart from the mouth, there was minimal increase in oxygen levels at the surrounding anatomic sites despite elevating FiO₂ levels.

HFNO may be safe to use during microlaryngeal laser surgery. By eliminating the endotracheal tube as a fuel source, risk of airway fire may be negligible. Our study safely applied CO₂ and KTP lasers for an uninterrupted 30 s with HFNO at 70 L/min and 100% FiO₂ producing no spark or fire.

NA Laryngoscope, 135:223-226, 2025.