Patient Ventilator Asynchrony in Critically Ill Children

项目摘要 机械通气的儿童经常有病人-呼吸机阻塞（PVA），尽管这是 在文献中描述不完全，很少在床边被发现。当一个通风 患者有自发努力，呼吸机尝试与患者同步，但PVA代表 患者的需求和呼吸机的输出之间不匹配。PVA常见于通风 与通气持续时间较长、感染风险增加、肺损伤、隔膜 功能障碍和不利的神经认知影响。虽然有许多类型的PVA，但它们并不相等。 有害的或普遍的。治疗策略应侧重于最有害的PVA形式。虽然我们仍然 我不知道哪种PVA亚型是真正最有害的，双循环（DC）呼吸（第二次呼吸是 在第一次呼吸完成之前输送）对伤害具有最强的生物相容性，因为DC 引起肺应力、应变、呼吸机引起的肺损伤和隔膜的离心收缩。 PVA在儿童中的研究不足，即使它可能更常见，并且在很大程度上未被识别 即使是训练有素的临床医生。此外，现有的儿科研究未能确定明确的关系， PVA和更差临床结局之间的关系，尽管这些研究并未关注最高风险 患者（如急性呼吸窘迫综合征（ARDS）患者）使用不同的定义， PVA及其亚型之间的关系，并已不充分的把握度，以评估PVA之间的关系， 亚型和结果。该提案将为儿童PVA的治疗策略奠定基础 并将填补关键的知识和实施差距，包括：（1）协调PVA的测量方法， 定义，（2）确定最有害的PVA亚型和风险患者，（3）使用创新和 准确的床边工具，以提高识别PVA。我们将利用专家和初步数据 来自三个顶尖的儿科研究小组，他们拥有使用精确方法来捕获 患者的神经呼吸努力，这对于正确识别PVA亚型至关重要。该提案将包括 前瞻性、多中心收集了200名使用精密呼吸机的儿童的呼吸机波形， 除了对现有波形进行详细的二次分析之外，还采用了捕获神经呼吸努力的技术 和超过350名儿童的临床数据。我们将使用因果推理和调解方法来评估 PVA亚型与临床和机制结局之间的关系， 随机对照试验（REDVent，R 01 HL 124666），其中PVA发生率和亚型可能在以下两组之间存在差异： 干预组和对照组。这项试验规定了一种机械通气策略， 与常规护理相比，自主呼吸可实现肺和膈肌保护性通气。

Project Summary Mechanically ventilated children often have patient-ventilator asynchrony (PVA) although this is incompletely characterized in the literature and infrequently recognized at the bedside. When a ventilated patient has spontaneous effort, the ventilator attempts to synchronize with the patient, but PVA represents a mismatch between what the patient wants and what the ventilator delivers. PVA is common in ventilated adults and is associated with longer duration of ventilation, increased risk of infection, lung injury, diaphragm dysfunction, and adverse neurocognitive effects. While there are many types of PVA, they are not equally harmful or prevalent. Therapeutic strategies should focus on the most harmful forms of PVA. Although we still don’t know which PVA subtypes are truly most harmful, Double Cycled (DC) breaths (where a second breath is delivered before the first breath is complete) have the strongest biological plausibility for harm, because DC induces lung stress, strain, ventilator induced lung injury and eccentric contraction of the diaphragm. PVA is understudied in children, even though it may be more common and goes largely unrecognized even by highly trained clinicians. Moreover, existing pediatric studies have failed to identify a clear relationship between PVA and worse clinical outcomes, although these studies have not focused on the highest risk patients (such as those with Acute Respiratory Distress Syndrome (ARDS)), have used different definitions for PVA and its subtypes, and have been inadequately powered to evaluate the relationship between PVA subtypes and outcome. This proposal will set the stage for therapeutic strategies to manage PVA in children and will fill crucial knowledge and implementation gaps including: (1) harmonizing how PVA is measured and defined, (2) identifying the most harmful PVA subtypes and the patients at risk, and (3) using innovative and accurate bedside tools to improve the recognition of PVA. We will leverage the expertise and preliminary data from three premier pediatric research groups who have the expertise to use precise methods to capture the patient’s neural respiratory effort, which is crucial to correctly identify PVA subtypes. This proposal will include prospective, multi-center collection of ventilator waveforms from 200 ventilated children using precise techniques to capture neural respiratory effort, in addition to detailed secondary analysis of existing waveforms and clinical data from over 350 children. We will use causal inference and mediation approaches to evaluate the relationship between PVA subtypes and clinical and mechanistic outcomes by leveraging data from a randomized controlled trial (REDVent, R01HL124666) where PVA rates and subtypes likely differ between intervention and control groups. This trial is prescribing a mechanical ventilation strategy promoting more spontaneous breathing to achieve lung and diaphragm protective ventilation, compared to usual care.