f =
= (whole body hematocrit) / (venous hematocrit)
Subjects for study: males from 7.9 to 88.4 and females from 15.5 to 80.5 years of age
|
Values of f
|
Female
|
Male
|
|
low end of range
|
0.757
|
0.766
|
|
mean
|
0.918
|
0.908
|
|
high end of range
|
1.157
|
1.106
|
The mean value for men and women was 0.911
calculated red cell volume in liters =
= (f ratio) * (venous hematocrit) * (plasma volume in L) / (1 - ((f ratio) * (venous hematocrit)))
The plasma volume can be measured after intravenous infusion of 125I-labelled albumin.
total blood volume in liters =
= (plasma volume) + (red cell volume in liters)
To calculate the red cell mass (RCM) the density of erythrocytes is multiplied by the red blood cell volume.
density of whole blood: 1.055
density of plasma: 1.027
demsity of erythrocytes 1.096
On page 27 the authors reference an f value of 0.864. If this is multiplied by the density of whole blood (1.055) then the value of 0.911 is returned, which is the mean value for f.
