Parameters:
(1) age of the patient in years
(2) estimated red blood cell volume (derived from estimated blood volume and hematocrit), as a measure of anemia
Using the equations from 02.08.01 to estimate blood volume from body surface area:
estimated blood volume (EBV) in liters in males =
= ((3.29 * (body surface area in square meters)) - 1.229)
estimated blood volume (EBV) in liters in females =
= ((3.47 * (body surface area in square meters)) - 1.954)
estimated red blood cell volume in mL =
= 1,000 * (estimated blood volume in liters) * (hematocrit as a decimal fraction)
ratio of age to estimated red blood cell volume =
= (age in years) / (estimated red blood cell volume)
Interpretation:
• The higher the ratio the greater the need for blood transfusion.
|
Ratio
|
Estimated Blood Transfusion Need
|
|
<= 0.030
|
<= 2 units
|
|
0.031 to 0.050
|
3 to 6 units
|
|
>= 0.051
|
7 to 13 units
|
