Central Venous Pressure (CVP) Changes do Not Predict Preload Unresponsiveness
Central Venous Pressure (CVP) Changes do Not Predict Preload Unresponsiveness
Passive leg raising (PLR) is routinely used to predict preload responsiveness in critically
 ill patients. However, real-time measurements of cardiac output are required to assess its
 effects. Some authors have suggested that in fluid non-responders, central venous pressure
 (CVP) increased markedly. By analogy with the CVP rules proposed by Weill et al to assess a
 fluid challenge, it has been hypothesized that an increase in CVP ≥ 5 mmHg during PLR can
 predict preload unresponsiveness.

 Objective Investigation of whether an increase in CVP ≥ 5 mmHg during PLR predict preload
 unresponsiveness diagnosed by the absence of increase in velocity-time integral (VTI) of the
 flow in the left ventricular outflow tract by more than 10% (4).

 Methods Critically ill patients with a central venous catheter in place and for whom the
 physician decided to test preload responsiveness by PLR were prospectively included.
 Transthoracic echocardiography was performed to obtain VTI. The CVP and VTI were measured
 before and during PLR.
Inclusion Criteria:

 -  ADULTS

 -  Patients presenting with shock or other signs of circulatory failure (tachycardia,
 oliguria)

 -  Need for the physician to test preload responsiveness

 -  Patients already equipped by a central venous catheter for the measurement of CVP

 Exclusion Criteria:

 -  patients<18 years old

 -  pregnancy

 -  instaility justifying rapid increase in cathecolamines