Specimen Integrity
Clots in
specimen:
Small
clots can increase clotting time – must be redrawn
Excessive aggitation of specimen:
Hemolysis
may indicate aggitation
Will
cause shortened clotting time – run with note
Excessive needle manipulation:
Increases
amount of tissue factor in tube
Can
lead to shortened clotting time
Lipemic or icteric specimens:
In
optical systems it may cause prolonged clotting time
In electromechanical systems (Fibrometer) it does not interfere with clot
detection
Prolonged application of tourniquet:
Can
lead to increased amounts of vWF & VIII
Can
lead to shortened clotting time