Platelet Count Procedure

A platelet count is a medical laboratory test that measures the number of platelets in a patient's blood. Platelets, also known as thrombocytes, are small, colorless cell fragments that play a crucial role in blood clotting.

Purpose of the Test

The primary purpose of a platelet count is to:

• Diagnose and monitor bleeding disorders, such as thrombocytopenia (low platelet count) or thrombocythemia (high platelet count)
• Evaluate the effectiveness of treatments for blood clotting disorders
• Monitor patients with conditions that affect blood cell production, such as bone marrow failure or leukemia
• Assess the risk of bleeding in patients undergoing surgery or other medical procedures

How the Test is Performed

A platelet count is typically performed using a complete blood count (CBC) test, which involves:

1. Collecting a blood sample from a vein in the arm or finger
2. Placing the blood sample into a tube containing an anticoagulant to prevent clotting
3. Sending the blood sample to a laboratory for analysis
4. Using automated equipment to count the number of platelets in the blood sample

Interpretation of Results

The normal range for a platelet count is typically between 150,000 and 450,000 platelets per microliter (µL) of blood. Abnormal results may indicate:

• Thrombocytopenia (low platelet count): fewer than 150,000 platelets/µL
• Thrombocythemia (high platelet count): more than 450,000 platelets/µL

Risks and Limitations

The risks associated with a platelet count are minimal and may include:

• Bleeding or bruising at the needle site
• Infection (rare)
• False results due to laboratory error or contamination of the blood sample

Special Considerations

Certain medications, such as heparin and aspirin, may affect platelet count results. Patients should inform their healthcare provider about any medications they are taking before undergoing a platelet count test.