Seattle Children's Hospital and Research Institute, Seattle, Washington.
Children's Hospital of Los Angeles, Los Angeles, California.
Respir Care. 2019 Apr;64(4):361-371. doi: 10.4187/respcare.06271. Epub 2019 Feb 5.
Different brands of volume-targeted modes may vary the location of tidal volume (V) monitoring and whether peak inspiratory pressure is adjusted based on inspiratory, expiratory or leak-compensated V. These variables may result in different levels of support provided to patients, especially when an endotracheal tube (ETT) leak is present. We hypothesized that there would be no differences in gas exchange, triggering, or work of breathing between volume-targeted modes of 3 different brands of equipment in a surfactant-deficient, spontaneously breathing animal model with and without an ETT leak.
Twelve rabbits (mean ± SD 1.61 ± 0.20 kg) were sedated, anesthetized, intubated, lavaged with 0.9% saline solution, and randomized in a crossover design so that each animal was supported by 3 different volume-targeted modes at identical settings with and without an ETT leak. After 30 min, arterial blood gas, V, and esophageal and airway pressure were recorded for each condition, and pressure-rate product and percentage of successfully triggered breaths were calculated.
Gas exchange and the pressure-rate product were not different between the ventilators in the absence of an ETT leak. When an ETT leak was introduced, volume-guarantee modes allowed a higher percentage of triggered breaths and peak inspiratory pressure, which resulted in higher minute ventilation, pH, and lower P than the pressure-regulated volume control mode ( < .05).
When a moderate ETT leak was present, volume-targeted modes that used proximal V monitoring and triggering with adaptive leak compensation capabilities appeared more effective in providing ventilation support than did a ventilator that used measurements obtained from the back at the ventilator and does not have leak compensation.
不同品牌的容量目标模式可能会改变潮气量（V）监测的位置，以及是否根据吸气、呼气或漏气补偿 V 来调整峰吸气压。这些变量可能会导致患者得到不同水平的支持，尤其是当存在气管内导管（ETT）泄漏时。我们假设，在缺乏表面活性剂、自主呼吸的动物模型中，当存在或不存在 ETT 泄漏时，三种不同品牌设备的容量目标模式之间在气体交换、触发或呼吸功方面不会有差异。
12 只兔子（平均±SD，1.61±0.20kg）镇静、麻醉、插管、用 0.9%生理盐水灌洗，采用交叉设计随机分为三组，使每只动物在相同设置下使用三种不同的容量目标模式，同时存在或不存在 ETT 泄漏。30 分钟后，记录每种情况下的动脉血气、V 和食管及气道压力，并计算压力-速率乘积和成功触发呼吸的百分比。
在不存在 ETT 泄漏的情况下，通气机之间的气体交换和压力-速率乘积没有差异。当引入 ETT 泄漏时，容积保证模式允许更高比例的触发呼吸和峰吸气压，从而导致更高的分钟通气量、pH 值和更低的 P（<0.05）。
当存在中度 ETT 泄漏时，使用近端 V 监测和具有自适应泄漏补偿能力的触发的容量目标模式似乎比使用呼吸机后部测量值且不具有泄漏补偿的通气机更有效地提供通气支持。
