Central Venous Pressure Trial Challenge

In patients with shock a primary goal of treatment is to restore and maintain organ perfusion, for which an adequate cardiac preload is required. Apart from the situations in which hypovolemia is evident and a favourable response to fluid administration will be seen, clinical and biological parameters often fail to predict hypovolemia. Inappropriate use of volume expansion carries out the risk of generating volume overload and pulmonary oedema and/or right-ventricular dysfunction. Consequently, reliable predictors of fluid responsiveness are needed especially in the early phase of cardiocirculatory deterioration. In the clinical setting, different static and dynamic indices have been shown to be useful indicators of cardiac preload. Central venous pressure (CVP) is widely used to measure right ventricular preload in patients requiring invasive hemodynamic monitoring. However, the use of the CVP is much criticized because CVP poorly predicts cardiac preload and volume status. However several decades ago, Weil and Henning proposed the fluid challenge technique, based on the 2-5 rule using CVP. There is a method for guiding volume repletion based on measurements of the patient's response to fluid load. This method had never validated in the prediction of fluid responsiveness. We therefore conducted a prospective study to assess whether the 2-5 rule using CVP could predict fluid responsiveness in mechanically ventilated patients with acute circulatory failure.