喉二氧化碳激光手术气道安全性分析

 目的 通过观察喉二氧化碳激光手术和麻醉管理中的危险，以及常用气管导管对二氧化碳激光耐受情况，分析喉二氧化碳激光手术的气道安全性，以期发现一些降低风险的方法，给临床医生以指导。方法 一是统计和分析我院2003年7月2日至2008年8月21日进行的704例喉二氧化碳激光手术所发生的危险情况；二是通过体外试验，观察注水和注空气时气管导管套囊在不同激光能量和不同激光切割方式下对二氧化碳激光的耐受情况，以及PVC气管导管在不同氧浓度、不同激光能量和不同激光切割方式下的燃烧情况。结果 在704例激光手术患者中，有92例气管套囊被击破，8例术中观察到火花，37例冒出浓烟，无1例发生燃烧或爆炸。体外试验中，水囊耐受二氧化碳激光的效果明显好于气囊（P<0.05），PVC气管导管在高浓度氧（超过50%）、高激光能量（大于8 W）和连续激光切割下易于燃烧，且剧烈程度随氧浓度和激光能量增高而加剧。结论 喉二氧化碳激光手术和麻醉存在较大风险，可以预见采取气管套囊注水、低氧浓度（50%以下）、低激光能量（8 W以下）和间断激光激发及术中采取盐水纱布保护是降低风险的良好措施。

Analysis on the safety of airway in CO2 laryngeal laser surgery

Objective To evaluate the safety of airway in CO₂ laryngeal laser surgery through observing the dangerous events during the operation and testing the tolerance of regular endotracheal catheter against CO₂ laser in order to provide guidance for surgeons and anesthetists. Methods First, 704 patients receiving CO₂ laryngeal laser operation from July 2, 2003 to August 21, 2008 were enrolled, and their risk events and causes were systematically analyzed. Second, in vitro experiment, we tested the tolerance of the PVC tube against different CO₂ laser energy in different cutting patterns when the cuff was inflated in water or air. We also tested the combustion conditions of the PVC tube in different oxygen concentration, laser energy and cutting patterns. Results Tracheal cuff were punctured by the laser in 92 of all 704 cases. Spark and dense smoke were observed in 8 and 37 cases respectively. There was no combustion or explosion in any of these cases. The tolerance against CO₂ laser was significantly better when the cuff was inflated in water than in air. The PVC tube was easy to light in high oxygen concentration (higher than 50%), high laser energy (higher than 8 watts) and continue laser cutting pattern. Moreover, the combustion would aggravate when the oxygen concentration or laser energy raise. Conclusions There were high risks in the surgical procedure and anesthesia of CO₂ laryngeal laser surgery. Some measures can be taken to reduce the risk, such as inflating the cuff by water instead of air, using low oxygen concentration (less than 50%) and laser energy (less than 8 watts), performing the laser with intermittent provocation pattern and protecting the tube using saline water gauze.