In critically ill patients, fluid infusion is aimed at increasing cardiac output and tissue perfusion. However, it may contribute to fluid overload which may be harmful. Thus, volume status, risks and potential efficacy of fluid administration and/or removal should be carefully evaluated, and monitoring techniques help for this purpose. Central venous pressure is a marker of right ventricular preload. Very low values indicate hypovolemia, while extremely high values suggest fluid harmfulness. The pulmonary artery catheter enables a comprehensive assessment of the hemodynamic profile and is particularly useful for indicating the risk of pulmonary oedema through the pulmonary artery occlusion pressure. Besides cardiac output and preload, transpulmonary thermodilution measures extravascular lung water, which reflects the extent of lung flooding and assesses the risk of fluid infusion. Echocardiography estimates the volume status through intravascular volumes and pressures. Finally, lung ultrasound estimates lung edema. Guided by these variables, the decision to infuse fluid should first consider specific triggers, such as signs of tissue hypoperfusion. Second, benefits and risks of fluid infusion should be weighted. Thereafter, fluid responsiveness should be assessed. Monitoring techniques help for this purpose, especially by providing real time and precise measurements of cardiac output. When decided, fluid resuscitation should be performed through fluid challenges, the effects of which should be assessed through critical endpoints including cardiac output. This comprehensive evaluation of the risk, benefits and efficacy of fluid infusion helps to individualize fluid management, which should be preferred over a fixed restrictive or liberal strategy.

在危重患者中，液体输注旨在增加心输出量和组织灌注。但是，它可能会导致体液过载，这可能是有害的。因此，应仔细评估液体给药和/或去除的容量状态、风险和潜在疗效，监测技术有助于实现这一目的。中心静脉压是右心室前负荷的标志。非常低的值表明血容量不足，而极高的值表明液体有害。肺动脉导管能够全面评估血流动力学特征，特别有助于通过肺动脉闭塞压力指示肺水肿风险。除了心输出量和前负荷外，经肺热稀释还测量血管外肺水，它反映了肺水肿的程度并评估了液体输注的风险。超声心动图通过血管内容量和压力估计容量状态。最后，肺部超声估计肺水肿。在这些变量的指导下，输注液体的决定应首先考虑特定的触发因素，例如组织灌注不足的迹象。其次，应权衡输液的益处和风险。此后，应评估容量反应性。监测技术有助于实现这一目的，尤其是通过提供实时和精确的心输出量测量。决定后，应通过液体挑战来进行液体复苏，其效果应通过包括心输出量在内的关键终点进行评估。这种全面的风险评估，