Though controversial,<unk>  measurement by<unk>  can estimate volume status, fluid responsiveness, and fluid tolerance
There is evidence to support that<unk>  diameter is consistently low in hypovolemia versus euvolemia<unk>  change can estimate fluid responsiveness with sensitivity of 0.78 and specificity of 0.86
Can use as a dynamic assessment after intervention such as giving fluids or passive leg raise
Dynamic changes is probably best measured in intubated patients
There is evidence to support that<unk>  diameter is consistently low in hypovolemia versus euvolemia<unk>  change can estimate fluid responsiveness with sensitivity of 0.78 and specificity of 0.86
IVC ultrasound
Aortic ultrasound
DVT ultrasound
D-dimer
Ankle-brachial index
ECG 
Thromboelastography 
Bubble study