Central Venous Pressure

Central venous pressure (CVP) (also known as: right atrial pressure; RAP) describes the pressure of blood in the thoracic vena cava, near the right atrium of the heart. CVP reflects the amount of blood returning to the heart and the ability of the heart to pump the blood into the arterial system.

It is a good approximation of right atrial pressure, which is a major determinant of right ventricular end diastolic volume. CVP has been, and often still is, used as a surrogate for preload, and changes in CVP in response to infusions of intravenous fluid have been used to predict volume-responsiveness (i.e. whether more fluid will improve cardiac output). However, there is increasing evidence that CVP, whether as an absolute value or in terms of changes in response to fluid, does not correlate with ventricular volume (i.e. preload) or volume-responsiveness, and so should not be used to guide intravenous fluid therapy. Nevertheless, CVP monitoring is a useful tool to guide hemodynamic therapy.