Sign in →

Epic Test Code LAB305 Coagulation Factor VII Activity Assay, Plasma

Additional Codes

MML Code: F_7

 

NY State Approved

Yes

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Reporting Name

Coag Factor VII Assay, P

Method Name

Optical Clot-Based

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Na Cit Frozen 14 days


Ordering Guidance


Coagulation testing is highly complex, often requiring the performance of multiple assays and correlation with clinical information. For that reason, we suggest ordering Coagulation Consultations.



Necessary Information


If priority specimen, mark request form, give reason, and request a call-back.



Specimen Required


Specimen Type: Platelet-poor plasma

Patient Preparation: Patient must not be receiving coumadin (warfarin) or heparin therapy. (If not possible for medical reasons, note on request.)

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Specimen must be collected prior to factor replacement therapy

2. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing

3. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.

4. Aliquot plasma into a plastic vial, leaving 0.25 mL in the bottom of centrifuged vial.

5. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally, -40° C or below.

Additional Information:

1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

2. Each coagulation assay requested should have its own vial.


Bassett Healthcare Network Clinical Laboratories Note:

Blood Tube Draw Volume
Min 90% draw volume  

Specimen Type

Plasma Na Cit

Specimen Minimum Volume

0.5 mL

Reference Values

Adults: 65-180%

Normal, full-term newborn infants or healthy premature infants may have decreased levels (≥20%) which increase within the first postnatal week but may not reach adult levels for ≥180 days postnatal.*

 

*See Pediatric Hemostasis References section in Coagulation Guidelines for Specimen Handling and Processing

Report Available

1 to 3 days

Day(s) Performed

Monday through Saturday

CPT Code Information

85230

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Useful For

Diagnosing congenital deficiency of coagulation factor VII

 

Evaluating acquired deficiencies associated with liver disease, oral anticoagulant therapy, and vitamin K deficiency

 

Determining degree of anticoagulation with warfarin to correlate with level of protein C

 

Investigation of a prolonged prothrombin time

Clinical Information

Factor VII is a vitamin K-dependent serine protease synthesized in the liver. It is a component of the extrinsic coagulation scheme, measured by the prothrombin time. Plasma biological half-life is about 3 to 6 hours. Deficiency may result in a bleeding diathesis.

Interpretation

Liver disease, vitamin K deficiency, or warfarin anticoagulation can cause decreased factor VII activity.

 

Newborn infants usually have levels 25% or more.

Cautions

Factor VII is the first vitamin K-dependent coagulation factor to decrease after starting warfarin therapy and one of the first to return to normal when anticoagulation is discontinued.

Specimen Retention Time

7 days