1 to 3 days

Monday through Friday 8:30 am to 4:30 pm. Run weekly.

Less than 5%

Two full 2.7 mL LIGHT BLUE top tubes, 3.2% sodium citrate. Hemostasis & Thrombosis Lab sodium citrate specimens must be processed and frozen within 2 hours of specimen collection. Stability is 14 days at -70 C.

Draw volume is critical due to the liquid anticoagulant. Allow tubes to fill by vacuum.
• Tubes with rubber stopper: fill to line on label.
• Tubes with plastic (Hemogard) cap: the fill level is above the top of the label.
• Syringe: do not remove the vacutainer stopper. Insert the needle through the stopper and allow the tube to fill by vacuum. Do not overfill the vacutainer.
• Pediatric tubes have no vacuum. Remove the cap and add blood to the 1.3 mL mark. Do not overfill.

OHSU clinics must cab specimen to the Core Lab, Hatfield Research Center, 9th Floor (room 9D20) if processing is delayed or not possible on site. A phone call is helpful to alert the lab at 503-494-7383.

Detailed specimen collection and processing instructions are located under Lab Sections and then the Hemostasis and Thrombosis (Opens in a new window) section.

For referral testing, submit one tube with 1.0 mL frozen platelet poor citrated plasma.

One full pediatric 1.3 mL LIGHT BLUE top tube, 3.2% sodium citrate. Hemostasis & Thrombosis Lab sodium citrate specimens must be processed and frozen within 2 hours of specimen collection. Stability is 14 days at -70 C.

For pediatric patients requiring multiple coagulation tests, please call 503-494-7383 regarding draw volumes.

50% to 129%
For children less than 6 months, see link to published reference ranges (Opens in a new window).

Avoid warfarin (Coumadin) therapy for 2 weeks and heparin therapy for 2 days prior to the test.

Assay to document factor VII deficiency. Deficiency of factor VII should be considered in patients with a prolonged prothrombin time but a normal APTT. While isolated deficiency is rare, two forms exist. Both are autosomal recessive and affect both sexes. In one form the VII molecules are decreased while In the second group an abnormally formed molecule is produced. Bleeding symptoms may be severe in homozygotes and include epistaxis, ecchymoses, GI bleeding, hemarthroses, menorrhagia, and umbilical cord hemorrhage. Fatal cerebral hemorrhage may occur. Heterozygotes are usually asymptomatic. Homozygotes have prolonged prothrombin time (corrected by adding normal plasma) but normal APTT, cephalin activated clotting time, and thrombin time.

Methodology: PT based clotting method.

High doses of standard heparin (greater than 1.0 U/mL) may interfere with a PT mixing study. Anti-Xa agents such as Rivaroxaban may also interfere with PT mixing studies. Clinical correlation is advised.

F7A
Factor 7
FVII A