Test Overview
Photo-optical clot determination with Factor VIII deficient substrate.
Detection of specific coagulation factor VIII deficiency
50-150%
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.
Test Details
2 hours
- Coagulation Factor VIII Assay
- Factor 8 Activity
- Factor VIII Assay
- Factor VIII:C Assay
- F8
STAT requests for this test will be performed on UMHS inpatients, Emergency Department patients, and Veterans Hospital patients.
Specimen Requirements
Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a polypropylene plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.
Additional Information
Decreased factor VIII may be seen in association with: hemophilia, von Willebrand's disease, hypothyroidism, and disseminated intravascular coagulopathy. Factor VIII is an acute phase reactant; levels rise during strenuous exercise, periods of acute stress, following surgery, and in most inflammatory conditions. Factor VIII levels are also increased in pregnancy, carcinoma, leukemia, liver or renal disease, diabetes, deep vein thrombosis, and myocardial infarction.