Sly P D, Bates J H, Milic-Emili J
Meakins-Christie Laboratories, McGill University, Montreal, Canada.
Pediatr Pulmonol. 1987 Nov-Dec;3(6):400-5. doi: 10.1002/ppul.1950030605.
The interrupter technique involves measuring the pressure changes at the airway opening during sudden cessation of flow and has been advocated for monitoring respiratory mechanics in artificially ventilated patients. The Siemens Servo Ventilator 900C has the ability to make airway occlusions without interrupting the patient's respiratory support. This study was performed to determine the suitability of the end-inspiratory occlusion facility of the ventilator for interrupter measurements of respiratory resistance and compliance. Measurements were made in a physical model of the respiratory system consisting of two parallel compartments, whose individual resistances and elastances were independently determined. The accuracy of the resistance measurements made using the ventilator were found to be dependent on the inspiratory flow. With an inspiratory flow of 100 ml/s, the resistance of the system could be measured to within 18% of the true value, and the static compliance could be measured to within 26% of the true value. Much of the error in these determinations was due to the finite closure time of the valve in the ventilator, and to the compliance of the gas in the tubing connecting the ventilator with the model. We conclude that the Siemens Servo Ventilator 900C can be used to conveniently obtain estimates of resistance and compliance in ventilated patients.
间断阻断技术涉及在气流突然停止时测量气道开口处的压力变化,并且已被提倡用于监测人工通气患者的呼吸力学。西门子Servo 900C呼吸机能够进行气道阻塞而不中断对患者的呼吸支持。本研究旨在确定该呼吸机的吸气末阻断功能对于呼吸阻力和顺应性的间断阻断测量的适用性。测量是在一个由两个平行腔室组成的呼吸系统物理模型中进行的,这两个腔室各自的阻力和弹性是独立测定的。发现使用该呼吸机进行的阻力测量的准确性取决于吸气流量。当吸气流量为100 ml/s时,系统阻力的测量值与真实值的误差在18%以内,静态顺应性的测量值与真实值的误差在26%以内。这些测定中的大部分误差是由于呼吸机中阀门的有限关闭时间以及连接呼吸机与模型的管道中气体的顺应性所致。我们得出结论,西门子Servo 900C呼吸机可用于方便地获取通气患者的阻力和顺应性估计值。