Table 3.

Thresholds and limits of dynamic indicators

Method	Threshold	Main limits
PPV (pulse pressure variation) SVV (stroke volume variation)	12%	Difficult to use in the following cases: patients with spontaneous breathing, patients with arrhythmia, patients with low tidal ventilation, and patients with low lung compliance
IVC diameter fluctuations	12%	Difficult to use in the following cases: patients with spontaneous breathing, patients with arrhythmia, and patients with low lung compliance
SVC diameter fluctuations	12–40%	Requires transesophageal echocardiography. Difficult to use in the following cases: patients with spontaneous breathing, patients with low tidal ventilation, and patients with low lung compliance
PLR (passive leg raising)	10%	Cardiac output is to be directly measured Difficult to use in the following cases: patients with lower limb defects, pregnant women, patients receiving vasoactive drugs, and patients with increased intra-abdominal pressure
EEO (end-expiratory occlusion test)	5%	Difficult to use in the following cases: non-intubated patients and patients who cannot hold their breath for more than 15 s
Low-dose fluid challenge (100 mL)	6–10%	Cardiac output needs to be measured directly and accurately
Fluid challenge (500 mL)	15%	Risk of fluid overload if repeated. Cardiac output needs to be measured directly