Irlbeck D
King Systems Corporation, Noblesville, Indiana, USA.
Respir Care Clin N Am. 1998 Jun;4(2):189-98.
The initial conditioning of the inhaled gases occurs in the upper respiratory tract. The conditioned gases are at approximately 32 degrees C and more than 95% relative humidity as they enter the lower respiratory tract. This level of heat and humidity will preserve the body's defense mechanisms. When the upper airway is bypassed the gases being delivered to the lower airways need to be as close to physiologic levels as possible based on the length of time the endotracheal tube will be in place. The delivery of gases above or below normal physiologic levels has been shown to produce clinical problems.
吸入气体的初始调节发生在上呼吸道。当调节后的气体进入下呼吸道时，其温度约为32摄氏度，相对湿度超过95%。这种热量和湿度水平将维持身体的防御机制。当绕过上呼吸道时，根据气管内导管留置的时间长短，输送到下呼吸道的气体需要尽可能接近生理水平。已证明输送高于或低于正常生理水平的气体会产生临床问题。
