Avalanche Phenomenon During Airways Opening in Acute Respiratory Distress Syndrome
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 50
- 试验地点
- 1
- 主要终点
- To assess the prevalence of "avalanche" phenomenon during low-flow lung inflation.
研究概览
简要总结
Acute respiratory distress syndrome accounts for 23% of mechanically ventilated patients and is associated with high mortality rate. Although life-saving, mechanical ventilation may worsen lung injury through two main mechanisms: lung overdistension and atelectrauma. Indeed, the cyclic opening and closure of airways during tidal ventilation may cause lung and bronchial injuries as suggested by animal models and autopsy findings. Complete airways closure has recently been described in 40% of patients with acute respiratory distress syndrome, and setting positive end-expiratory pressure above the airway opening pressure may limit atelectrauma. However, animal and mathematical models suggest that above the airway opening pressure, more distal airways open unevenly according to their own opening pressure, resulting in an "avalanche"-like phenomenon during lung inflation. This phenomenon has never been described in humans. A better understanding of the opening of airways in acute respiratory distress syndrome may help to limit ventilation-induced lung injury and to improve outcomes.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Moderate-to-severe acute respiratory distress syndrome within the first 72 hours after meeting the Berlin definition criteria:
- •Within 1 week of a known clinical insult or new or worsening respiratory symptoms;
- •Bilateral opacities (not fully explained by effusions, lobar/lung collapse, or nodules);
- •Respiratory failure not fully explained by cardiac failure or fluid overload;
- •PaO2/FiO2 ≤ 200 mmHg with positive end-expiratory pressure ≥ 5 cmH2O.
- •Absence of spontaneous breathing efforts
- •Consent to participate to the study from the patient and/or its surrogate
排除标准
- •Pneumothorax
- •Broncho-pleural fistula
- •Tracheostomy
- •Hemodynamic instability
- •Severe hypoxemia
- •Suspected of proven intracranial hypertension
- •Chronic obstructive lung disease
- •Pacemaker or defibrillator
- •Decision to withhold of withdraw life-sustaining measures
- •Under protection
结局指标
主要结局
To assess the prevalence of "avalanche" phenomenon during low-flow lung inflation.
时间窗: At inclusion
The distribution of pressure drops on low-flow inflation pressure-volume curves will be described and plotted on a log-log scale graph. "Avalanche" phenomenon will be defined if this distribution follows power law (i.e. is linear on a log-log scale) with a R2 ≥ 0.80. The prevalence of "avalanche" phenomenon will be described as frequency and 95% confidence interval.
次要结局
- To compare characteristics of patients and their outcomes according to the existence of "avalanche" phenomenon during low-flow lung inflation.(Day 28)
- To assess the existence of an inflection point on the low-flow deflation pressure-volume curve.(At inclusion)
- To assess the airway pressure value of the inflection point on the low-flow deflation pressure-volume curve in patients with an inflexion point on the low-flow deflation pressure-volume curve(At inclusion)