Methods and Apparatuses for Central Venous Pressure Measurement Status

A noninvasive method for determining central venous pressure in an individual, comprising:

• (a) subjecting a measurement region of a limb of the individual to a plurality of transmural pressures by subjecting the limb to varying external pressure using a pressure management system or by placing the limb in a plurality of configurations such that the height of a measurement site relative to the individual's heart varies or by resistance breathing, or a combination thereof;
• (b) using a light source and a light-sensitive detector to optically determine collapse of veins in a measurement region of the limb, and the transmural pressure at which venous collapse occurs;
• (c) determining a vertical separation between the right atrium of the individual's heart and the measurement region;
• (d) determining the central venous pressure from the external pressure at which venous collapse occurs and from the vertical separation.

A method of determining central venous pressure in an individual comprising:

• (a) providing a pressurizable enclosure, and placing the limb in the enclosure and providing a seal around the limb;
• (b) determine determining the height of a measurement region of the limb relative to an anatomical reference;
• (c) using the pressurizable enclosure to subject the limb to a plurality of external pressures;
• (d) providing an optical measurement system responsive to blood presence in a measurement region of the limb, and use the optical measurement system to determine a measure of blood volume in the measurement region;
• (e) determining the central venous pressure from the relationship of the measure of blood volume and corresponding external pressure, and from the determined height.