Which value would first indicate hypervolemia in a patient?

The value that would first indicate hypervolemia in a patient is central venous pressure (CVP). CVP is a direct measurement of the pressure within the right atrium and reflects the volume status of the patient. Elevated CVP suggests an increase in blood volume and fluid overload, which is characteristic of hypervolemia.

As fluid volume increases, the right atrium experiences greater pressure due to the increased venous return, leading to an elevated CVP. This makes it an early and sensitive indicator for detecting fluid excess before more advanced signs or symptoms develop.

In contrast, while mean pulmonary artery pressure (mPAP), pulmonary capillary wedge pressure (PCWP), and systemic vascular resistance (SVR) can also be influenced by volume status, they tend to reflect more complex interactions. For instance, an increase in PCWP may follow after CVP changes, as it indicates left atrial pressure and reflects pulmonary circulation status rather than the systemic venous return directly. Thus, CVP is the most immediate and practical choice for early identification of hypervolemia.