SVC flow velocity monitoring can sensitively guide volume therapy during surgery
Body is capable to maintain arterial pressure even during substantial hemorrhagic events. Latter sudden pressure drop to pre-shock or even shock happens when vasoconstriction can no longer maintain the desired perfusion. Volemic changes can be detected earlier due to preload monitoring via SVC Doppler. Peak blood flow velocities are even more sensitive to the preload changes than the overall venous return.
LBNP stands for Lower Body Negative Pressure. Healthy subjects were positioned with their lower body into a negative pressure chamber. Negative pressure was applied progressively and Superior Vena Cava flow was monitored.
