Stable factor or Proconvertin or Autoprothrombin I
(Factor VII)

The factor VII assay is a blood test to measure the activity of factor VII. This is one of the proteins in the body that helps the blood clot.

Sample type:

Whole blood Light Blue top (Buffered Na Citrate)

Uses:

Useful for the detection of a single factor congenital homozygous or heterozygous deficiency or an acquired deficiency due to a lack of Vitamin K or liver disease and evaluate an isolated prolonged PT

Precautions:

• Patient should not be receiving heparin. If so, this should be noted on the request form. Heparin therapy can affect certain coagulation factors.

• Patients with a hematocrit level >55% must have a special tube made to adjust for the hematocrit; contact lab for a special tube.

• Must be tested within 4 hours.

• Avoid Coumadin for two weeks and heparin therapy for two days prior to the test.

Interfering factors:

Decreased factor VII activity may be related to:

• Factor VII deficiency (a bleeding disorder that affects the ability of blood to clot)

• Disorder in which the proteins that control blood clotting become over active (disseminated intravascular coagulation)

• Fat malabsorption (not absorbing enough fat from your diet)

• Liver disease (such as cirrhosis)

• Vitamin K deficiency

• Taking blood thinners

Pre analytical errors:

• Gross hemolysis

• clotted specimen

• frozen specimen

• improper labeling

Corrective action:

• Good mixing

• Propre collection of the sample

Post analytical errors:

• Transcription errors in reporting

• Report sent to the wrong location

• Report illegible

• Report not sent

Reference Range:

5- 20 mg/dl