Microlaryngeal Laser Surgery Using High‐flow Nasal Ventilation at Two Oxygen Concentration Deliveries.

Objectives: Ventilation using 100% oxygenation creates a risk of fire during laser microlaryngeal surgery (MLS). The purpose of this study is to describe the technique of transnasal high‐flow ventilation using laser safe (30%) oxygen conditions, measure the intraoperative real‐time laryngeal oxygen concentration, and examine patient saturation status using this technique. Methods: Prospective IRB approved study of patients undergoing tubeless laser MLS using high‐flow nasal oxygenation. Delivered oxygen concentration was reduced from 100% to 30% before lasering using an oxygen‐air blender then increased to 100% post‐laser procedure. Outcome measures included time for laryngeal oxygen concentration to equalize to laser safe levels; time to, methods of and duration of rescue ventilation; and desaturation rates and apnoeic times at both 100% and 30% oxygen deliveries. Results: Fifty patients were recruited (mean age = 47.4 years). Mean laryngeal oxygen concentration (%) at 100% and 30% deliveries was 98.46 and 31.45, respectively. Mean (SD) of laryngeal oxygen concentration equalization time to 30% (seconds) was 9.4 (3.69). At 30% oxygen delivery desaturation rate was faster and apneic time shorter compared with 100%. Eighteen patients required rescue (jet) ventilation and they had a faster apneic desaturation rate (%/minute) than patients not requiring rescue. Mean (SD) apneic time (minutes) at 30% delivery was 4.56 (2.25) and 4.41 (2.18) in rescue versus non‐rescue groups respectively. BMI was the only significant predictor of desaturation rate at 30% oxygen delivery. Conclusion: It is possible to achieve a safe time window for use of laser during MLS using transnasal humidified high‐flow ventilation by delivering 30% oxygen concentration. Level of Evidence: 4 Laryngoscope, 133:634–639, 2023 [ABSTRACT FROM AUTHOR]