Variables
Description
What is this formula?
The Plasma Volume Estimate formula calculates the volume of plasma contained within the blood based on total blood volume and hematocrit.
When to use it
Use this formula when assessing intravascular fluid status, evaluating blood loss, estimating plasma exchange volumes, or performing physiological and clinical calculations involving blood components.
Example
Data:
BV = 5.0 L
Hct = 45 %
Formula:
PV = BV × (1 − Hct/100)
Substitution:
PV = 5.0 × (1 − 45/100)
PV = 5.0 × 0.55
Result:
PV = 2.75 L
The estimated plasma volume is 2.75 liters.
Applications
- Hematology
- Critical care medicine
- Plasma exchange therapy
- Fluid status assessment
- Cardiovascular physiology
Note
This formula provides an estimate of plasma volume based on measured or estimated blood volume and hematocrit. Actual plasma volume may vary due to trapped plasma within red blood cell fractions, measurement methods, and physiological conditions. More advanced techniques using tracer dilution methods can provide greater accuracy.