(2) Platelet administration sets contain a filter that is similar to a standard
blood filter, but housed in a small drip chamber, or a needle syringe device. Only
approximately 3 percent of platelets are lost by passage through these filters.
Microaggregate filters may trap a large proportion of platelets, and should not be used
for platelet administration.
3-4.
BLOOD PRODUCTS USED TO REPLACE PLASMA COAGULATION
FACTORS
a. Single Coagulation Factor Deficiency.
(1)
Factor VIII.
(a) Deficiencies of coagulation factors may exist as isolated or
combined deficiencies and may be acquired or inherited. Isolated inherited deficiencies
of each at the coagulation factors have been described, although the most common is
hemophilia A, or Factor VIII deficiency. Opinions differ regarding the level of Factor VIII
that is desirable to be attained in the management or prevention of bleeding episodes.
(b) One unit of Factor VIII equals the Factor VIII activity of 1 ml of
fresh, normal, pooled plasma. Factor VIII levels are usually reported as a percentage of
normal (see Table 3-2).
Blood
Volume
Units* Factor VIII
Units* Factor VIII
per
per
Components
ml
Container
ml
Fresh whole blood
517.5
225
1.0
(24 hr)
Fresh liquid plasma
225
225
1.0
Fresh-frozen plasma
225
190
0.8
Cryoprecipitate
10
100
10.0
Commercial concentrate
20 to 30
200 to 1,000
10 to 33
(*One unit of Factor VIII is that amount of Factor VIII activity in 1 ml of fresh normal
plasma.)
Table 3-2. Blood components and fractions containing factor VIII.
(c)
The amount of Factor VIII required for transfusion can be calculated
as follows:
1 Weight (kg) x 70-ml/kg blood volume (ml)
MD0846
3-9