Clotting; factor VIII, VW factor, ristocetin cofactor
CPT4 code
Name of the Procedure:
Clotting Factors Test; Factor VIII, von Willebrand Factor, Ristocetin Cofactor Activity Assay
Summary
The clotting factors test is a blood test that measures the levels and functionality of specific proteins (Factor VIII and von Willebrand factor) vital for proper blood clotting. The ristocetin cofactor activity assay assesses the interaction between von Willebrand factor and platelets, crucial for effective clot formation.
Purpose
This test is used to diagnose bleeding disorders such as Hemophilia A or von Willebrand disease. It helps determine whether there's a defect in blood clotting proteins that could lead to excessive bleeding.
Indications
- Unexplained bleeding or bruising
- Family history of bleeding disorders
- Pre-surgical screening in patients with a history of bleeding
- Women with heavy menstruation
- Recurrent nosebleeds
- Joint bleeds without trauma
Preparation
- No special fasting or diet required.
- Inform the doctor of any medications being taken, especially blood thinners.
- A brief physical examination and medical history review may be conducted.
Procedure Description
- A healthcare professional cleans the skin above a vein, usually in the arm.
- A tourniquet is applied to make the vein more visible.
- A needle is inserted into the vein to draw a blood sample.
- The blood sample is sent to a laboratory for analysis of Factor VIII levels, von Willebrand Factor, and ristocetin cofactor activity.
- The area from which the blood was drawn is covered with a bandage.
Duration
The blood draw itself takes about 5 minutes. Laboratory analysis may take a few days to complete.
Setting
The procedure is performed in a laboratory, hospital, or outpatient clinic.
Personnel
- Phlebotomist or Nurse (blood draw)
- Laboratory Technicians (sample analysis)
- Hematologist or Physician (diagnosis and treatment planning)
Risks and Complications
- Minor bruising or swelling at the needle site
- Lightheadedness or fainting during or after the blood draw
- Rarely, infection at the needle insertion site
Benefits
- Accurate diagnosis of bleeding disorders
- Development of personalized treatment plans
- Prevention of complications related to undiagnosed clotting disorders
Recovery
- Most patients experience no significant recovery time.
- Pressure and a bandage applied to the needle site typically suffice.
- Normal activities can usually be resumed immediately.
Alternatives
- Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT) tests for overall clotting function.
- Genetic testing to identify hereditary clotting disorders.
- Platelet function tests for other types of clotting issues.
Patient Experience
- Mild discomfort or a slight pinch during the needle insertion.
- Minimal pain afterward, with some possible slight bruising.
- Results discussion with a healthcare provider to determine any necessary follow-up or treatment.