Platelets are essential for the initial phase of hemostasis.
Platelets are prepared by using a centrifuge to separate the
platelet-rich plasma from the donated unit of whole blood. These random
donor platelet concentrates contain about 60mL of plasma and small
numbers of red blood cells and leukocytes. If ABO compatible platelets
are unavailable, ABO incompatible platelets can be substituted with very
Platelets may also be obtained from a single donor by a process
known as apheresis, or plateletpheresis. In this process, blood is drawn
from the donor into an apheresis instrument which separates the blood
into its components, retains some of the platelets, and returns the
remainder of the blood to the donor. Apheresis platelets are equivalent
to approximately 5-6 pooled units and have a small number of red blood
cells and leukocytes.
Platelets are used to treat thrombocytopenia and/or platelet
function abnormalities. Platelets should not be used to treat
thrombocytopenia due to platelet destruction such as ITP, TTP, HUS,
HELLP syndrome, etc.
The volume of a dose of platelets is approximately 350-400mL. The
initial recommended dose for an adult is 6 units of pooled random donor
platelets or one apheresis unit; for pediatrics, the dose is 5-10mL/kg.
This dose will usually increase the platelet count by approximately