Effects of Positive End-expiratory Pressure and Tidal Volume on Fluid Responsiveness of Acute Respiratory Distress Syndrome
Effects of Positive End-expiratory Pressure and Tidal Volume on Fluid Responsiveness of Acute Respiratory Distress Syndrome.
研究概览
详细说明
In septic critically ill mechanically ventilated patients with acute circulatory failure, inadequate volume resuscitation leads to multiple organ failure. Early goal-directed therapy emphasizes early and aggressive hemodynamic support in patients with severe sepsis and septic shock. On the other hand, because of increased microvascular permeability and capillary leakage, conservative fluid management and more aggressive restriction in fluid accumulation to reduce lung water and tissue edema has been suggested by acute respiratory distress syndrome net. Fluid responsiveness refers to the ability of the heart to increase its stroke volume in response to volume load. Accurately predicting volume responsiveness will be beneficial in obviating the need for unnecessary fluid loading, and in detecting patients who may benefit from a volume load.
By inducing cyclic changes in pleural and transpulmonary pressure, mechanical ventilation results in cyclic changes in the preload and afterload, and therefore, the cyclic variation in systolic and pulse pressure. Recently, a systemic review concluded that dynamic preload indicator [pulse pressure variation (PPV), stroke volume variation (SVV)] are highly accurate in predicting volume responsiveness in critically ill patients. However, this technique is limited to patients who receive controlled ventilation with adequate tidal volume (> 8 ml/Kg) and sedation or paralysis is needed to abolish the spontaneous ventilation.
For acute respiratory distress syndrome patients, protective ventilatory strategy suggested low tidal volume to 6 ml/Kg. On the contrary, high PEEP needed for acute respiratory distress syndrome to prevent VALI induces a leftward shift to the steep pat of the Frank-Starling curve and increase the fluid responsiveness. Whether the dynamic preload indicators (PPV and SVV) are still effective in acute respiratory distress syndrome patients for predicting fluid responsiveness remain controversial.
Passive leg raising (PLR), by inducing a gravitational transfer of blood from the lower part of the body toward the central circulatory compartment, can be considered as a brief "self volume challenge". Recently, a systemic review and meta-analysis concluded that PLR-induced changes in cardiac output reliably predict fluid responsiveness regardless of ventilation mode, underlying cardiac rhythm and technique of measurement and can be recommended for routine assessment of fluid responsiveness in the majority of ICU population. More importantly, this prediction remains very valuable in patients with cardiac arrhythmias or spontaneous breathing activity.
Respiratory variations in the pulse oximeter plethysmographic waveform amplitude (ΔPOP) have been shown to be able to predict fluid responsiveness in mechanically ventilated patients. The main advantage of this index is that it is noninvasive, widely available, and inexpensive. Perfusion index (PI), the percentage between the infrared pulsatile and nonpulsatile signal, reflects the amplitude of the pulse oximeter waveform. Recently, Pleth Variability Index (PVI), derived from perfusion index, affords a continuous monitoring of ΔPOP. PVI has been shown to be correlated to ΔPOP and PPV and has been demonstrated to be equivalent to SVV as a predictor of fluid responsiveness in ventilated patients during major surgery. However, whether the PVI can predict the fluid responsiveness in acute respiratory distress syndrome necessitating low tidal volume and high PEEP is not clear.
Because of the aforementioned contrasting effects of low tidal volume and high PEEP on the prediction of fluid responsiveness, the aim of this study is to compare the relative predicting power of the dynamic preload indicator (PPV, SVV), passive leg raising test, and PVI on the fluid responsiveness of acute respiratory distress syndrome ventilated with various PEEP levels or various tidal volumes.
研究类型
注册 (预期的)
联系人和位置
学习地点
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Taipei、台湾、10507
- Chang Gung Memorial Hospital
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参与标准
资格标准
适合学习的年龄
接受健康志愿者
有资格学习的性别
取样方法
研究人群
描述
Inclusion Criteria: Clinical signs of inadequate tissue perfusion were defined
- systolic blood pressure< 9 mmHg(or a decrease > 50 mmHg in previously hypertensive patients)
- need of vasopressive drugs(dopamine > 5 ug/Kg/min or norepinephrine)
- urine output<0.5 mL/Kg/hr for at least 2 hrs
- tachycardia (heart rate >100/min)
- presence of skin mottling.
Exclusion Criteria:
- patient with spontaneous respiratory activity
- cardiac arrhythmia
- known intracardiac shunt
- contraindication for passive leg raising(PLR),e.g.,pelvic trauma
- unstable spine injuries or leg amputation
- hemodynamic instability during the procedure,defined by a variation in heart rate or blood pressure of>10%over the 15-min period before starting the protocol
- Patients of renal failure necessitate renal replacement therapy will be excluded also.
学习计划
研究是如何设计的?
设计细节
队列和干预
团体/队列 |
干预/治疗 |
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ARDS with acute circulatory failure
acute respiratory distress syndrome with acute circulatory failure with infusion of 6% tetrastarch for a total of 500ml
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研究衡量的是什么?
主要结果指标
结果测量 |
措施说明 |
大体时间 |
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increase of cardiac output after volume expansion
大体时间:4 hours
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Patients are classified to be volume expansion responders or nonresponders according to whether the volume expansion induced cardiac index increase at the end of hydroxyethyl starch infusion is ≧15% or < 15% of baseline cardiac index.
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4 hours
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合作者和调查者
调查人员
- 首席研究员:Chung-Chi Huang, MD、Chang Gung Memorial Hospital
研究记录日期
研究主要日期
学习开始
初级完成 (预期的)
研究注册日期
首次提交
首先提交符合 QC 标准的
首次发布 (估计)
研究记录更新
最后更新发布 (估计)
上次提交的符合 QC 标准的更新
最后验证
更多信息
与本研究相关的术语
关键字
其他研究编号
- CGMF IRB 100-4473A3
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