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.
調査の概要
詳細な説明
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.
研究の種類
入学 (予想される)
連絡先と場所
研究場所
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Taipei、台湾、10507
- Chang Gung Memorial Hospital
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参加基準
適格基準
就学可能な年齢
健康ボランティアの受け入れ
受講資格のある性別
サンプリング方法
調査対象母集団
説明
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.
研究計画
研究はどのように設計されていますか?
デザインの詳細
コホートと介入
グループ/コホート |
介入・治療 |
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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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この研究は何を測定していますか?
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
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increase of cardiac output after volume expansion
時間枠: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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協力者と研究者
捜査官
- 主任研究者:Chung-Chi Huang, MD、Chang Gung Memorial Hospital
研究記録日
主要日程の研究
研究開始
一次修了 (予想される)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (見積もり)
学習記録の更新
投稿された最後の更新 (見積もり)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
本研究に関する用語
キーワード
その他の研究ID番号
- CGMF IRB 100-4473A3
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