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

Abstract

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

Safety and Utility of Transnasal Humidified Rapid‐Insufflation Ventilatory Exchange (THRIVE) for Laser Laryngeal Surgery

“…A recent investigation across 50 patients using THRIVE while undergoing laser laryngeal surgery (LLS) assessed the safety of lowering the FiO 2 to 30% prior to laser use. Although there were no airway fires in the study, the mean apnea time was 4.59 minutes, significantly shorter compared to the times found in prior non‐laser laryngeal studies which used 100% oxygen 1,14 . The parameters for safe use of THRIVE particularly at oxygen concentrations above 30% in laser laryngeal surgery have not been well explored.…”

“…Although there were no airway fires in the study, the mean apnea time was 4.59 minutes, significantly shorter compared to the times found in prior non-laser laryngeal studies which used 100% oxygen. 1,14 The parameters for safe use of THRIVE particularly at oxygen concentrations above 30% in laser laryngeal surgery have not been well explored.…”

Optimizing nonintubated laryngeal microsurgery: The effectiveness and safety of superior laryngeal nerve block with high-flow nasal oxygen—A prospective cohort study

“…Airway ignition is another potential risk during airway laser surgery under an HFNO supply. 20 In the recent work, Novakovic et al 21 demonstrated that for nonintubated LMS using HFNO, an FiO 2 delivery decrease from 100% to 30% may be possible to achieve a safe time window. This viable safe time window for the use of laser during LMS while using HNFO at a 30% oxygen concentration.…”

Tube or tubeless: an anesthetic strategy for upper airway surgery

“…In addition to the indications (patent airway and short laryngeal surgery) and contraindications (skull base defect, increased intracranial pressure, and unstable hemodynamics) for HFNO, anesthesiologists should consider risk factors when determining the duration of tubeless anesthesia maintenance. In previous studies, elevated body mass index (BMI) was the only significant predictor of oxygen desaturation during HFNO [ 4 , 13 , 30 , 37 , 40 ]. BMI > 30 kg/m 2 was associated with a greater risk of requiring rescue ventilation, similar to alterations in respiratory physiology in obesity.…”

“…Therefore, airway surgeries using lasers under HFNO have the potential risk of airway fires. However, successful case reports of orolaryngeal surgeries using laser and electrocautery with HFNO have been published [ 30 , 33 , 35 , 40 ]. They revealed that there was no risk of airway fire despite delivering 100% oxygen at up to 70 L/min because there were no combustible materials such as polyvinyl chloride endotracheal tubes or gauze.…”