Airway fire during awake tracheostomy using high-flow nasal oxygen

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR) Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part II

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factor, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

Feasibility and safety of THRIVE in transoral laser microsurgery

OBJECTIVE

Transnasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) presents obvious advantage in laryngeal surgery and Transoral Laser Microsurgery (TLM). Airway fire represents a rare complication of TLM and may be the most important limitation in the use of THRIVE. The objective was to evaluate the different operating conditions of the TLM with THRIVE with regard to fire risk.

EXPERIMENT

In this report, we assessed the risk of fire by varying the Fraction of Inspired Oxygen (FiO2), the Laser Energy, and the placement of endolaryngeal surgical and ventilatory equipment in a porcine model for TLM.

RESULTS

Fire, sparks and smoke were reported. No combustion occurred with THRIVE in the absence of an endolaryngeal material. Fire occurred systematically while delivering between 3 and 5 W Carbon dioxide (CO2) Laser direct shot on a dry laryngeal cotton. Conclusion THRIVE-TLM should never be performed using a dry cotton or a plastic endolaryngeal material.

Fire safety study on high-flow nasal oxygen in shared-airway surgeries with diathermy and laser: simulation based on a physical model

High-flow nasal oxygen (HFNO) has been used in "tubeless" shared-airway surgeries but whether HFNO increased the fire hazard is yet to be examined. We used a physical model for simulation to explore fire safety through a series of ignition trials. An HFNO device was attached to a 3D-printed nose with nostrils connected to a degutted raw chicken. The HFNO device was set at twenty combinations of different oxygen concentration and gas flow rate. An electrocautery and diode laser were applied separately to a fat cube in the cavity of the chicken. Ten 30 s trials of continuous energy source application were conducted. An additional trial of continuous energy application was conducted if no ignition was observed for all the ten trials. A total of eight short flashes were observed in one hundred electrocautery tests; however, no continuous fire was observed among them. There were thirty-six events of ignition in one hundred trials with laser, twelve of which turned into violent self-sustained fires. The factors found to be related to a significantly increased chance of ignition included laser application, lower gas flow, and higher FiO₂. The native tissue and smoke can ignite and turn into violent self-sustained fires under HFNO and continuous laser strikes, even in the absence of combustible materials. The results suggest that airway surgeries must be performed safely with HFNO if only a short intermittent laser is used in low FiO₂.