Assessing Lung Inhomogeneity During Ventilation for Acute Hypoxemic Respiratory Failure
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 20
- 试验地点
- 2
- 主要终点
- Intratidal ventilation heterogeneity
研究概览
简要总结
Mechanical ventilation can cause damage by overstretching the lungs, especially when the lungs are collapsed or edematous. Raising ventilator pressures can reduce lung collapse and this can prevent overstretching from mechanical ventilation. It remains uncertain how much pressure (PEEP - positive end-expiratory pressure) should be used on the ventilator and how to identify patients who will benefit from higher ventilator pressures vs. lower ventilator pressures. The investigators are using a unique new imaging technology, electrical impedance tomography (EIT), to study this problem and to determine the safest and most effective ventilator pressure level. The results of this study will inform future trials of higher vs. lower PEEP strategies in mechanically ventilated patients.
详细描述
Patients participating in this physiological cross-over randomized trial will undergo a series of PEEP maneuvers designed to assess lung recruitability, PEEP responsiveness, and optimal PEEP. EIT imaging and esophageal manometry will be employed throughout the protocol to quantify the effect of PEEP on lung function. Patients will be randomized to be ventilated at PEEP levels supplied by the ExPRESS strategy or by the EIT hyperdistention/collapse algorithm. The biological response will be assessed by measuring serum cytokines.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- None
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
- •Acute (≤7 days) hypoxemia with PaO2:FiO2 ratio less than or equal to 200 mm Hg
- •Oral endotracheal intubation and mechanical ventilation
- •Bilateral airspace opacities on chest radiograph or CT
排除标准
- •Contraindication to EIT electrode placement (burns, chest wall bandaging limiting electrode placement)
- •Contraindication to esophageal catheter placement (recent upper GI surgery, actively bleeding esophageal varices)
- •Respiratory failure predominantly due to cardiogenic cause or fluid overload
- •Ongoing hemodynamic instability (requiring 2 vasopressor agents by continuous infusion AND rising vasopressor infusion rate requirements in the previous 8 hours)
- •Ongoing ventilatory instability (P/F < 70 mm Hg, pH < 7.2; ventilator driving pressures, PEEP, or FiO2 increasing by more than 25% in previous 30 minutes)
- •Intracranial hypertension (suspected or diagnosed by medical team)
- •Known or suspected pneumothorax recognized within previous 72 hours
- •Bronchopleural fistula
- •Bridge to lung transplant
- •Recent lung transplantation (within previous 6 weeks)
- •Attending physician deems the transient application of high airway pressures (>40 cm H2O) to be unsafe
结局指标
主要结局
Intratidal ventilation heterogeneity
时间窗: Assessed after completion of 3 hours on randomized strategy (EIT vs ExPRESS)
A measure of variation in the distribution of ventilation throughout the lung as detected by electrical impedance tomography
次要结局
- Change in ratio of partial pressure of oxygen (PaO2) to inspired fraction of oxygen (FiO2) ratio following a standardized increased in PEEP(Assessed 10 minutes after step PEEP increase from 6-8 to 16-18 cm H2O)
- Respiratory mechanics (transpulmonary driving pressure)(Assessed after completing 3 hours on the randomized PEEP strategy (EIT vs ExPRESS))
- Difference in the optimal PEEP levels identified by several different PEEP titration strategies(Assessed immediately after completion of decremental PEEP titration procedure)