Factor VIII Activity : 1000326

Message
The aliquot must remain frozen. Freeze thaw cycle will adversely affect specimen integrity. CRITICAL FROZEN: Separate specimens must be submitted when multiple tests are ordered.

Test Code
F8A or 1000326

Alias/See Also
Coagulation Factor VIII Activity Assay, Plasma; Factor VIII; Factor VIII Assay; Hemophilia A; Factor Assay

CPT Codes
85240

Instructions
Blue top tube, 3.2% sodium citrate.
• Obtain venous blood by clean venipuncture. Avoid slow-flowing draws and/or traumatic venipunctures as either of these may result in an activated or clotted specimen. Do not use needles smaller than 23 gauge. Do not leave the tourniquet on for an extended length of time before drawing the sample.
• A pilot tube (non-additive or light blue tube) before drawing coagulation specimens in light blue vacuum tubes is only necessary when using a butterfly blood collection set as this will cause reduced draw volume in the first tube. Discard the pilot tube.
• Fill light blue tubes as far as vacuum will allow and mix by gentle inversion. Exact ratio of nine parts blood to one part anticoagulant must be maintained. Inadequate filling of the sample tube will alter this ratio and may lead to inaccurate results. Patients who have hematocrit values above 55 percent should have the anticoagulant adjusted to maintain the 9:1 ratio. Use the following formula to determine the amount of anticoagulant to use: [(100 – Hct) / (595 – Hct) ]* total volume = amount of anticoagulant required.
• After collecting the blood, examine the tube to ensure that it is filled to within 90% of the fill line.
• Note: Specimens containing heparin should not be used for coagulation studies. If possible, stop heparin therapy before the draw to avoid contamination. Heparin interferes with most clotting assays. If heparinized line must be used to obtain the sample, flush line with 5mL saline and discard the first 5 mL of blood drawn into a syringe, or 6 “dead space” volumes of the line.

Transport Container
Blood collected in 3.2% sodium citrate (light blue top tube). Proper blood to anticoagulant ratio is required. The tubes must be at a 100 ± 10% fill volume to maintain the correct ratio. Centrifuge light blue-top tube at 1500 g for no less than 15 minutes or speed/time to consistently yield platelet-poor plasma (<10,000/µL). Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer, and place into a plastic transport tube (Min. 0.5 mL). Immediately freeze the aliquot and ship on dry ice.

Transport Temperature
Frozen.

Specimen Stability
After separation from cells: Ambient: Unacceptable; Refrigerated: Unacceptabe; Frozen: 14 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Marked hemolysis; marked icterus; marked lipemia; received thawed; received refrigerated; received room temperature

Methodology
Clotting

Setup Schedule
Monday - Saturday

Report Available
1-3 days

Reference Range
50-200 %

Performing Laboratory
med fusion



The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.