The Effect of Inspiratory Oxygen Fraction on the Ratio of Partial Arterial Oxygen Pressure and Inspiratory Oxygen Fraction (PaO2/FiO2 Ratio) in Mechanically Ventilated Patients With and Without Mild to Moderate ARDS
试验速览
- 阶段
- 不适用
- 发起方
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- The effect of FiO2 on the PaO2/FiO2-ratio
研究概览
简要总结
The PaO2/FiO2 ratio is frequently used to determine the severity of lung injury in mechanically ventilated patients. However, several mathematical models have shown that PaO2/FiO2 ratio depends on FiO2. The relationship is complex and depends on numerous physiological variables, including shunt fraction, and arterio-venous oxygen difference. The nonlinear relation between PaO2/FiO2 and FiO2 underlines the limitations describing the intensity of hypoxemia using PaO2/FiO2 and is thus of major importance for the clinician. Surprisingly, this relationship has only been assessed mathematically. Obviously, the accuracy of the mathematical relationship depends on the input variables used.
The current study is designed to assess the PaO2/FiO2 vs FiO2 relation in mechanically ventilated patients without ARDS (n =10) and with mild or moderate ARDS (n =10). In order to explain the dependency of the PaO2/FiO2 on FiO2, shunt fraction and alveolar - arterial oxygen difference ((A-a)DO2) will be determined in these patients.
详细描述
Rationale:
The PaO2/FiO2 ratio is frequently used to determine the severity of lung injury in mechanically ventilated patients. However, several mathematical models have shown that PaO2/FiO2 ratio depends on FiO2. The relationship is complex and depends on numerous physiological variables, including shunt fraction, and arterio-venous oxygen difference. The nonlinear relation between PaO2/FiO2 and FiO2 underlines the limitations describing the intensity of hypoxemia using PaO2/FiO2 and is thus of major importance for the clinician. Surprisingly, this relationship has only been assessed mathematically. Obviously, the accuracy of the mathematical relationship depends on the input variables used.
The current study is designed to assess the PaO2/FiO2 vs FiO2 relation in mechanically ventilated patients without ARDS (n =10) and with mild or moderate ARDS (n =10). In order to explain the dependency of the PaO2/FiO2 on FiO2, shunt fraction and alveolar - arterial oxygen difference ((A-a)DO2) will be determined in these patients.
Objective:
To study the relation between PaO2/FiO2-ratio and FiO2
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Diagnostic
- 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
- •All mechanically ventilated patients, admitted to the Intensive Care Unit of VU-Medical Center post cardiac surgery without ARDS and with mild to moderate ARDS. In order to be eligible to participate in this study, a subject must meet all of the following criteria:
- •Mechanically ventilated patients
- •Stable hemodynamics
- •Stable haemoglobin level
- •Stable body temperature
- •Stable level of sedation
- •Pulmonary-Artery and Artery catheter
排除标准
- •Incomplete revascularization after CABG
- •Cardiac ischemia
- •Neurotrauma
研究组 & 干预措施
Without ARDS
Patients admitted to the ICU after cardiac surgery with a PaO2/FiO2 ratio > 300.
Modulation of FiO2: FiO2 will be reduced to 21% or until peripheral oxygen saturation of 92%, whatever occurs first. Subsequently FiO2 will be increased up to 100%.
干预措施: Modulation of FiO2 (Drug)
With mild to moderate ARDS
Patients admitted to the ICU after cardiac surgery with a PaO2/FiO2 ratio > 100 and < 300.
Modulation of FiO2: FiO2 will be reduced to 21% or until peripheral oxygen saturation of 92%, whatever occurs first. Subsequently FiO2 will be increased up to 100%.
干预措施: Modulation of FiO2 (Drug)
结局指标
主要结局
The effect of FiO2 on the PaO2/FiO2-ratio
时间窗: 2 hours
To study the effect of FiO2 on the PaO2/FiO2-ratio in mechanically ventilated patients post cardiac surgery without ARDS and with mild to moderate ARDS
次要结局
- Shunt fraction, arteriovenous oxygen difference and alveolar - arterial oxygen difference(2 hours)
研究者
Angelique Spoelstra-de Man
Principal Investigator
Amsterdam UMC, location VUmc