Mean systemic pressure as predictor of successful fluid responsiveness in sepsis

The assessment of the cardiovascular state in critically ill patients is
subject to difficulties in terms of the fact that several hemodynamic
parameters, for example mean arterial blood pressure (MAP) and cardiac output
(CO) supply insufficient information about the circulating volume and cardiac
performance. There is a clinical need to adequate determination of
intravascular volume status and therefore reliable predictors of fluid
responsiveness are highly relevant. However, in determining the fluid status of
a patient, the lack of appreciation of the venous side of the circulation
persists today, which is greatly due to the inability to appropriately assess
the venous side of the circulation. The importance of the venous part of the
circulation is moreover reflected by the fact that an increase in venous
resistance does reduce CO many times more than a similar increase in arterial
resistance. Mean systemic filling pressure (Pms), which is defined as the
pressure equal to the pressure which would be measured if the heart should
suddenly stop pumping and all (arterial and venous) the pressures in the entire
circulatory system should be brought to equilibrium instantaneously, is a good,
complete and reliable reflection of the total intravascular fluid compartment.
Passive leg raising (PLR) represents a *self-volume challenge* that predicts
preload responsiveness and the transient hemodynamic changes on venous return
can be directly monitored in ventilated patients, provided that there is an
intact circulation, in order to test the amount of volume responsiveness.

Predicting fluid responsiveness during PLR and fluid challenge (FC) by changes
in (Pms).

Prospective, observational study

Additional bleeding risk due to puncture of femoral artery instead of radial
artery.