Revisiting Fire Safety Guidelines in CO₂ Laser Airway Surgery.

Area of Science:

• Medical Devices
• Surgical Safety
• Laser Surgery

Background:

• Airway fire is a known risk during endoscopic laser surgery, often managed by lowering fraction of inspired oxygen (FiO2).
• This study investigates fire risk specifically in CO2 laser tubeless airway surgery.

Purpose of the Study:

• To evaluate the impact of ventilation type (high-flow vs. jet ventilation), laser wattage, and FiO2 on airway fire risk.
• To establish safer parameters for CO2 laser surgery.

Main Methods:

• A cadaveric porcine larynx and lung model was used.
• Trials involved high-flow ventilation (HFV) and jet ventilation, with varied FiO2 levels and laser power settings.
• Onset time and frequency of different flame types (brief, expansive, blowtorch) were recorded.

Main Results:

• Jet ventilation consistently produced expansive flames, with higher incidence and shorter onset times compared to HFV.
• Increasing laser wattage decreased flame onset time and increased frequency.
• Higher FiO2 levels did not significantly impact flame occurrence, except for brief flames with HFV.

Conclusions:

• Laser wattage is a more critical factor than FiO2 in determining fire risk during CO2 laser surgery.
• HFV is a potentially safer ventilation method, with defined safe zones for wattage and FiO2.
• A FiO2 limit of 30% is recommended for jet ventilation due to consistent flame generation.