Use of a Helium/Oxygen Carrier Gas Mixture for Inhalation Anesthesia during Laser Surgery in the Airway of the Horse by B. Driessen, L. E. Nann and L. Klein; A0618.0403

The use of lasers during surgery in the airway of the horse bears various hazards of which airway combustion is the most severe. This risk is of particular concern in anesthetized animals breathing an oxygen-rich gas mixture. Though total intravenous anesthesia has been commonly advocated for laser procedures, laser surgery in the airway of the horse can be performed more safely under inhalation anesthesia, if the inspired oxygen concentration (FiO2) is kept low. Use of a heliumoxygen (He/O2) gas mixture and low FiO2 (< 0.4) offers the advantage of significantly decreasing the risk of airway combustion while maintaining adequate arterial oxygenation in the majority of equine patients.