Roy Soham, Smith Lee P
Pediatric Otolaryngology, The University of Texas Health Science Center at Houston, Medical School, Department of Otorhinolaryngology-Head & Neck Surgery, Houston, Texas, USA
Hofstra North Shore-LIJ School of Medicine, Chief of Pediatric Otolaryngology, Cohen Children's Medical Center, Long Island, New York, USA.
Otolaryngol Head Neck Surg. 2015 Jan;152(1):67-72. doi: 10.1177/0194599814555853. Epub 2014 Oct 24.
Laser surgery of the larynx and airway remains high risk for the formation of operating room fire. Traditional methods of fire prevention have included use of "laser safe" tubes, inflation of a protective cuff with saline, and wet pledgets to protect the endotracheal tube from laser strikes. We tested a mechanical model of laser laryngeal surgery to evaluate the fire risk.
Mechanical model.
Laboratory.
An intubation mannequin was positioned for suspension microlaryngoscopy. A Laser-Shield II cuffed endotracheal tube was placed through the larynx and the cuff inflated using saline. Wet pledgets covered the inflated cuff. A CO2 laser created an inadvertent cuff strike at varying oxygen concentrations. Risk reduction measures were implemented to discern any notable change in the outcome after fire.
At 100% FiO2 an immediate fire with sustained flame was created and at 40% FiO2 a near immediate sustained flame was created. At 29% FiO2, a small nonsustained flame was noted. At room air, no fire was created. There was no discernible difference in the severity of laryngeal damage after the fire occurred whether the tube was immediately pulled from the mannequin or if saline was poured down the airway as a first response.
While "laser safe" tubes provide a layer of protection against fires, they are not fire proof. Inadvertent cuff perforation may result in fire formation in low-level oxygen enriched environments. Placement of wet pledgets do not provide absolute protection. Endotracheal tube (ETT) cuffs should be placed distally well away from an inadvertent laser strike while maintaining the minimum supplemental oxygen necessary.
喉部和气道的激光手术仍然具有较高的手术室起火风险。传统的防火方法包括使用“激光安全”导管、用盐水充盈保护套以及使用湿纱布保护气管内导管免受激光照射。我们测试了激光喉手术的机械模型以评估火灾风险。
机械模型。
实验室。
将插管人体模型放置于悬吊式显微喉镜检查位置。将一根带有套囊的Laser-Shield II气管内导管经喉部置入，并用盐水充盈套囊。湿纱布覆盖充盈的套囊。二氧化碳激光在不同氧浓度下意外照射套囊。实施降低风险措施以辨别火灾后结果的任何显著变化。
在100%的吸入氧浓度（FiO2）下引发了立即燃烧且火焰持续的火灾，在40% FiO2下引发了近乎立即燃烧且火焰持续的火灾。在29% FiO2时，观察到一小团非持续火焰。在室内空气中，未引发火灾。火灾发生后，无论导管是立即从人体模型中拔出，还是作为第一反应向气道内倒入盐水，喉部损伤的严重程度均无明显差异。
虽然“激光安全”导管提供了一层防火保护，但它们并非防火的。意外的套囊穿孔可能会在低水平富氧环境中导致火灾形成。放置湿纱布并不能提供绝对保护。气管内导管（ETT）套囊应放置在远离意外激光照射的远端，同时维持所需的最低补充氧气量。
