Abstract

Methods for prediction of fluid responsiveness are needed during shock resuscitation. Fluid therapy remains a cornerstone in the treatment of shock and influences the outcomes directly. Excess or insufficient fluid administration is associated with increased morbidity and mortality. Prediction of fluid responsiveness means that a hemodynamic variable is used to determine how likely a patient is to respond to fluid bolus with a significant increase in their cardiac output. Depending on the response to fluids, patients are either responders or non-responders. Clinicians often rely on static indices of preload, like central venous pressure and pulmonary artery occlusion pressure, as a guide for fluid therapy. Unfortunately, whilst easy for use, these indices are of minimal value as predictors of fluid responsiveness. More recent research highlights hemodynamic variables related to cardiopulmonary interactions during mechanical ventilation. These dynamic indices, viz. stroke volume variation and pulse pressure variation, show a significantly better predictive value. To maximize the predictive value of dynamic indices, several conditions must be fulfilled. Another method for prediction of fluid responsiveness is represented by the functional hemodynamic tests: a heterogenous group of bedside tests for preload responsiveness. Fluid challenges remain popular, although repetitive use can be harmful. Hemodynamic tests, like passive leg raising or end-expiratory occlusion, modify the preload without fluid administration. Regardless of the test used, monitoring of cardiac output is needed to evaluate the heart’s response to changes in preload. This review gives an overview of the methods for fluid responsiveness prediction, including those explored in the COVID-19 context.

摘要

在休克复苏期间需要预测液体反应性的方法。液体疗法仍然是休克治疗的基石，并直接影响结果。补液过多或不足与发病率和死亡率增加有关。液体反应性的预测意味着使用血流动力学变量来确定患者对液体推注反应且心输出量显着增加的可能性。根据对液体的反应，患者是有反应者或无反应者。临床医生通常依赖静态前负荷指数，如中心静脉压和肺动脉闭塞压，作为液体治疗的指导。不幸的是，虽然易于使用，但这些指数作为液体反应性的预测指标的价值很小。最近的研究强调了与机械通气期间心肺相互作用相关的血流动力学变量。这些动态指标，即。每搏量变化和脉压变化，显示出明显更好的预测值。为了最大化动态指数的预测值，必须满足几个条件。另一种预测液体反应性的方法是功能性血液动力学测试：一组异质的床边前负荷反应性测试。流体挑战仍然很受欢迎，尽管重复使用可能是有害的。血流动力学测试，如被动抬腿或呼气末闭塞，无需补液即可改变前负荷。无论使用何种测试，都需要监测心输出量以评估心脏对前负荷变化的反应。本综述概述了液体反应性预测的方法，包括在 COVID-19 背景下探索的方法。