Central venous pressure: principles, measurement, and interpretation.

Central venous pressure (CVP), an estimate of right atrial pressure, has been used to assess cardiac preload and volume status in critically ill patients, assist in the diagnosis of right-sided heart failure, and guide fluid resuscitation. It is determined by the interaction between cardiac function and venous return. CVP measurements are relatively easy to obtain; however, because of the complex relationship between CVP, cardiac output, and the vascular system, they may be difficult to interpret. This article reviews the physiologic principles of CVP, indications for its use, technical aspects and pitfalls of CVP measurements, and interpretation of the information obtained.