How To Use CPT Code 85520

CPT 85520 describes the measurement of heparin concentration in a plasma specimen. 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 85520?

CPT 85520 can be used to measure the concentration of heparin in a plasma specimen. This test is performed by a lab analyst and involves various technical steps to evaluate the residual free factor Xa in the plasma. The test may include adding bovine antithrombin III (AT III) and factor Xa to the specimen, forming an inactive complex that can be detected using chromogenic methods.

2. Official Description

The official description of CPT code 85520 is: ‘Heparin assay.’

3. Procedure

1. The lab analyst evaluates a plasma specimen to measure heparin concentration.
2. The test may involve adding bovine antithrombin III (AT III) and factor Xa to the plasma specimen.
3. An inactive complex of factor Xa–AT III–heparin is formed, which can be detected using chromogenic methods.
4. The lab analyst measures the light absorption of a specific wavelength to determine the concentration of heparin in the plasma specimen.

4. Qualifying circumstances

CPT 85520 may be ordered by clinicians in specific circumstances, such as evaluating patients on heparin therapy or investigating prolonged test results for activated thromboplastin time. It is not typically used for routine monitoring of therapy with unfractionated heparin, as the activated partial thromboplastin time test is commonly used for such monitoring.

5. When to use CPT code 85520

CPT code 85520 should be used when there is a clinical need to measure heparin concentration in a plasma specimen. It is important to consider the specific circumstances and indications for this test, as it is not routinely used for all patients on heparin therapy.

6. Documentation requirements

To support a claim for CPT 85520, documentation should include:

• Indication for the test, such as evaluation of heparin concentration in patients on heparin therapy
• Details of the technical steps performed during the test, including the addition of bovine antithrombin III and factor Xa
• Date and time of the test
• Results of the test, including the measured heparin concentration
• Signature of the lab analyst performing the test

7. Billing guidelines

When billing for CPT 85520, ensure that the test is performed by a qualified lab analyst. It is important to follow the specific guidelines provided by payers regarding the billing of this code. Additionally, consider any separate codes that may be required for specimen collection, such as venipuncture.

8. Historical information

CPT 85520 was added to the Current Procedural Terminology system on January 1, 1990. There have been no updates to the code since its addition.

9. Examples

1. A clinician orders CPT 85520 to measure heparin concentration in a patient treated with low-molecular weight heparin.
2. Following a prolonged activated thromboplastin time test result, a clinician requests CPT 85520 to evaluate heparin concentration in a patient.
3. A clinician uses CPT 85520 to measure heparin concentration when the required dose for a normal activated thromboplastin time test is unexpectedly high.
4. As part of a comprehensive evaluation, a clinician orders CPT 85520 to assess heparin concentration in a patient with a suspected coagulation disorder.
5. In a research study, CPT 85520 is utilized to measure heparin concentration in plasma specimens from multiple patients.
6. A clinician requests CPT 85520 to monitor heparin concentration in a patient undergoing cardiac surgery.
7. Following the initiation of heparin therapy, a clinician orders CPT 85520 to assess the patient’s response to the treatment.
8. In a clinical trial, CPT 85520 is used to measure heparin concentration in plasma samples collected from study participants.
9. A clinician utilizes CPT 85520 to evaluate heparin concentration in a patient with a suspected heparin overdose.
10. As part of a preoperative assessment, a clinician orders CPT 85520 to measure heparin concentration in a patient scheduled for surgery.