Name of the Procedure:

Pyruvate kinase assay (PK test)

Summary

A pyruvate kinase assay is a blood test used to measure the activity level of the enzyme pyruvate kinase, which is essential for the proper functioning of red blood cells.

Purpose

The procedure helps diagnose pyruvate kinase deficiency, a rare genetic disorder that causes chronic hemolytic anemia. It aids in determining the underlying cause of hemolytic anemia and guides appropriate treatment plans.

Indications

• Unexplained hemolytic anemia
• Persistent fatigue and jaundice
• Positive family history of pyruvate kinase deficiency
• Chronic pallor and enlarged spleen

Preparation

• Fasting is not required for this test.
• Continue regular medications unless advised otherwise by your healthcare provider.
• Inform your doctor of any recent transfusions, as these can affect test results.

Procedure Description

1. A healthcare provider will clean the skin with an antiseptic.
2. A tourniquet is tied around the upper arm to fill the veins with blood.
3. A needle is inserted into a vein (usually in the arm) to draw a blood sample.
4. The blood sample is sent to the lab where the enzyme activity is measured using specialized equipment.

Duration

The blood draw itself takes approximately 5-10 minutes. Lab analysis may take several days to a week to complete.

Setting

The procedure is usually performed in a hospital, outpatient clinic, or diagnostic laboratory.

Personnel

• Phlebotomist or nurse (for blood draw)
• Laboratory technician (for test processing)
• Hematologist or primary care physician (for result interpretation)

Risks and Complications

• Pain or discomfort at the needle site
• Bruising or bleeding
• Rare: infection at the puncture site
• Fainting or dizziness

Benefits

• Accurate diagnosis of pyruvate kinase deficiency
• Tailored treatment plans based on specific enzyme levels
• Improved management of symptoms related to hemolytic anemia

Recovery

• Follow post-blood draw instructions (e.g., pressing on the puncture site to stop bleeding).
• Resume normal activities immediately unless advised otherwise.
• Follow-up may include additional tests or consultations based on results.

Alternatives

• Genetic testing for pyruvate kinase deficiency
• Complete blood count (CBC) and other blood tests to assess anemia
• Bone marrow biopsy in complex cases (more invasive)

Patient Experience

• Mild discomfort during blood draw, akin to a quick pinch
• Possible light bruising or tenderness at the puncture site
• Typically minimal to no pain following the procedure
• Results discussion with healthcare provider to determine next steps