Name of the Procedure:

Factor XII (Hageman factor) Activity Assay

Summary

The Factor XII (Hageman) activity assay is a blood test that measures the activity of Factor XII, a protein involved in the blood clotting process. It helps identify issues related to abnormal clotting and bleeding.

Purpose

The assay addresses conditions related to improper blood clotting, particularly where there is a deficiency or abnormality in Factor XII. The goal is to diagnose potential bleeding disorders or clotting abnormalities to guide further treatment.

Indications

• Unexplained prolonged bleeding or bruising
• Family history of bleeding disorders
• Abnormal results from initial screening tests like PT (Prothrombin Time) or aPTT (Activated Partial Thromboplastin Time)
• Pre-surgical evaluation for patients with a history of clotting issues

Preparation

• No specific fasting is required.
• Patients should inform their doctor of any medications they are taking, as some may need to be stopped prior to the assay.
• A physical examination and review of medical history may precede the test.

Procedure Description

1. A healthcare professional will draw a blood sample from a vein, usually in the arm.
2. The blood is collected in a tube with an anticoagulant to prevent clotting.
3. The sample is sent to a laboratory where the activity of Factor XII is measured using specialized tests.
4. Results are analyzed to determine the activity level of Factor XII.

Duration

The blood draw typically takes about 5-10 minutes. Laboratory analysis may take a few hours to a few days, depending on the facility.

Setting

The blood draw is performed in a hospital, outpatient clinic, or specialized lab.

Personnel

• Phlebotomist or Nurse for blood draw
• Laboratory technicians for sample analysis
• Hematologist for result interpretation

Risks and Complications

• Minor bleeding or bruising at the blood draw site.
• Rarely, infection or fainting may occur.

Benefits

• Accurate diagnosis of clotting or bleeding disorders.
• Identification of inherited or acquired Factor XII deficiencies, guiding appropriate treatment.

Recovery

• Minimal recovery is needed.
• Patients can resume normal activities immediately after the blood draw.
• Follow-up with a healthcare provider to discuss results and necessary treatments.

Alternatives

• Extended PT (Prothrombin Time) and aPTT (Activated Partial Thromboplastin Time) tests.
• Genetic testing for inherited clotting disorders.
• Each alternative has varying degrees of specificity and sensitivity.

Patient Experience

• The patient may feel a slight pinch or discomfort during the blood draw.
• Mild soreness or bruising at the puncture site is common.
• Emotional comfort measures include reassurance and clear communication from healthcare providers.