Revisiting Fire Safety Guidelines in CO₂ Laser Airway Surgery

Introduction The potential for airway fire during endoscopic laser surgery is well known, typically addressed by reducing FiO 2 levels. This study revisits these established practices in CO 2 laser tubeless airway surgery. Materials and Methods Using a cadaveric porcine larynx and lung model, we conducted trials with high‐flow (HFV) and jet ventilation. We varied FiO 2 levels and laser power settings to record the onset and number of brief, expansive, and blowtorch flames. Results Flames were observed in all jet ventilation trials. Multivariable model results showed that increasing laser wattage decreased onset times for expansive/blowtorch flames and increased their frequency ( p < 0.05). Increased FiO 2 changes were not significant ( p > 0.05). HFV trials revealed no expansive flames at 4 W at 100%, 6 W at 70%, and 10 W at 50% FiO 2 . Increasing wattage shortened flame onset and increased frequency across all flames ( p < 0.01), while increasing FiO 2 only reduced onset time for brief flames ( p < 0.05). Jet ventilation led to higher flame incidence and shorter onset times than HFV ( p < 0.05). Conclusion Fire risk during CO 2 laser surgery in oxygen‐rich environments is influenced more by wattage, rather than FiO 2 levels. Jet ventilation consistently produced expansive flames, even at lower FiO 2 levels and wattage, supporting a FiO 2 limit of 30% for this ventilation technique. Our findings support HFV as a potentially safer option for CO 2 laser surgery, with safe zones of 4 W at 100%, 6 W at 70%, and 10 W at 50% FiO 2 , provided laser application is under 30 s. Our model's calculation of excess risk from wattage increments can help surgeons assess this fire risk.