How To Use CPT Code 85384

CPT 85384 describes the clotting activity of fibrinogen, a protein found in plasma that reacts with thrombin to form fibrin. This article will cover the description, procedure, qualifying circumstances, appropriate usage, documentation requirements, billing guidelines, historical information, similar codes and billing examples.

1. What is CPT Code 85384?

CPT 85384 can be used to describe the clotting activity of fibrinogen, which is a protein found in plasma. This code is used when a lab analyst performs a test to determine the level of conversion of fibrinogen to fibrin in a plasma specimen. The test is based on the principle that the clotting time of diluted plasma is inversely proportional to fibrinogen levels when excess thrombin is present. The test may involve adding thrombin to diluted plasma and measuring increased viscosity over time to determine fibrinogen activity levels.

2. Official Description

The official description of CPT code 85384 is: ‘Fibrinogen; activity.’

3. Procedure

1. The lab analyst performs a test to evaluate the clotting activity of fibrinogen in a plasma specimen.
2. The test may involve adding thrombin to diluted plasma and measuring increased viscosity over time.
3. The clotting time of the diluted plasma is inversely proportional to fibrinogen levels.
4. The lab analyst determines the fibrinogen activity levels based on the test results.

4. Qualifying circumstances

CPT 85384 is used when clinicians order a test to detect increased or decreased fibrinogen levels in a plasma specimen. This test may be ordered based on symptoms such as abnormal bleeding or clotting, or based on prior abnormal test results. Decreased fibrinogen levels may be inherited in a condition known as afibrinogenemia or acquired due to conditions such as disseminated intravascular coagulation (DIC) or liver disease. Increased fibrinogen levels are associated with an increased risk for developing arterial thromboembolism.

5. When to use CPT code 85384

CPT code 85384 should be used when a test is performed to evaluate the clotting activity of fibrinogen in a plasma specimen. It is appropriate to bill this code when the test is ordered to assess fibrinogen levels in patients with symptoms or prior abnormal test results related to abnormal bleeding or clotting. This code should not be used for testing related to specific conditions or diseases.

6. Documentation requirements

To support a claim for CPT 85384, the documentation should include:

• Reason for ordering the test, such as abnormal bleeding or clotting symptoms or prior abnormal test results
• Details of the test performed, including the method used and any additional steps involved
• Test results indicating the fibrinogen activity levels
• Signature of the lab analyst performing the test

7. Billing guidelines

When billing for CPT 85384, ensure that the test is performed by a lab analyst and that the documentation supports the medical necessity of the test. This code should not be reported with other codes for specimen collection. It is important to distinguish between CPT 85384 for fibrinogen activity and CPT 85385 for fibrinogen antigen. Some payers may pay separately for specimen collection using a code such as 36415 for venipuncture.

8. Historical information

CPT 85384 was added to the Current Procedural Terminology system on January 1, 1993. There have been no updates to the code since its addition.

9. Examples

1. A lab analyst performing a test to evaluate the clotting activity of fibrinogen in a plasma specimen for a patient with abnormal bleeding symptoms.
2. A clinician ordering a test to assess fibrinogen levels in a patient with prior abnormal test results related to clotting.
3. A lab analyst measuring increased viscosity over time in diluted plasma to determine fibrinogen activity levels for a patient with suspected afibrinogenemia.
4. A test performed to evaluate fibrinogen activity levels in a plasma specimen for a patient with liver disease.
5. A lab analyst adding thrombin to diluted plasma and measuring clotting time to assess fibrinogen levels in a patient at risk for arterial thromboembolism.
6. A clinician ordering a test to detect increased fibrinogen levels in a plasma specimen for a patient with a history of abnormal clotting.
7. A lab analyst performing a test to evaluate the clotting activity of fibrinogen in a plasma specimen for a patient with symptoms of disseminated intravascular coagulation (DIC).
8. A test performed to assess fibrinogen levels in a plasma specimen for a patient with abnormal bleeding and suspected afibrinogenemia.
9. A lab analyst measuring increased viscosity over time in diluted plasma to determine fibrinogen activity levels for a patient with a history of abnormal clotting.
10. A clinician ordering a test to detect decreased fibrinogen levels in a plasma specimen for a patient with liver disease.