How To Use CPT Code 85293

CPT 85293 describes the clotting test known as the high molecular weight kininogen assay, or Fitzgerald factor assay. 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 85293?

CPT 85293 is used to identify the high molecular weight kininogen assay, also known as the Fitzgerald factor assay. This test is performed by a lab analyst to determine the presence of high molecular weight kininogen in a patient’s plasma. The test may involve mixing the patient’s plasma with a high molecular weight kininogen-deficient substrate and evaluating the results with a chromogenic assay or triggering coagulation and measuring clot formation.

2. Official Description

The official description of CPT code 85293 is: ‘Clotting; high molecular weight kininogen assay (Fitzgerald factor assay)’

3. Procedure

1. The lab analyst performs all technical steps to assess the presence of high molecular weight kininogen in the patient’s plasma.
2. The lab method may involve mixing the patient’s plasma with a high molecular weight kininogen-deficient substrate and evaluating the results with a chromogenic assay.
3. Alternatively, the lab analyst may add a partial thromboplastin time reagent and calcium to trigger coagulation and optically measure clot formation.

4. Qualifying circumstances

Clinicians may order the high molecular weight kininogen assay when investigating the cause of a prolonged partial thromboplastin time (PTT) test in patients without a bleeding disorder. This test is typically ordered when other clotting factor tests, such as factors VIII, IX, XI, XII, and prekallikrein, are normal.

5. When to use CPT code 85293

CPT code 85293 should be used when performing the high molecular weight kininogen assay to assess the presence of Fitzgerald factor in a patient’s plasma. It is important to note that this code should not be used for testing specific conditions but rather to investigate the cause of a prolonged PTT test when other clotting factor tests are normal.

6. Documentation requirements

To support a claim for CPT code 85293, the documentation should include:

• Reason for ordering the high molecular weight kininogen assay
• Details of the lab method used, such as mixing the patient’s plasma with a high molecular weight kininogen-deficient substrate or triggering coagulation
• Results of the assay

7. Billing guidelines

When billing for CPT code 85293, it is important to ensure that the test is performed by a lab analyst. Additionally, some payers may separately reimburse for specimen collection using a code such as 36415 for venipuncture.

8. Historical information

CPT code 85293 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 lab analyst performs the high molecular weight kininogen assay to assess the presence of Fitzgerald factor in a patient’s plasma.
2. The high molecular weight kininogen assay is ordered to investigate the cause of a prolonged PTT test in a patient without a bleeding disorder.
3. A lab analyst mixes the patient’s plasma with a high molecular weight kininogen-deficient substrate and evaluates the results using a chromogenic assay.
4. The high molecular weight kininogen assay is performed to determine the presence of Fitzgerald factor in a patient’s plasma when other clotting factor tests are normal.
5. A lab analyst triggers coagulation in the patient’s plasma and optically measures clot formation to assess the presence of high molecular weight kininogen.
6. The high molecular weight kininogen assay is performed to investigate the cause of a prolonged PTT test when other clotting factor tests, such as factors VIII, IX, XI, XII, and prekallikrein, are normal.
7. A lab analyst performs the high molecular weight kininogen assay using a chromogenic assay to determine the presence of Fitzgerald factor in a patient’s plasma.
8. The high molecular weight kininogen assay is ordered to investigate the cause of a prolonged PTT test in a patient without a bleeding disorder, with normal results for other clotting factor tests.
9. A lab analyst adds a partial thromboplastin time reagent and calcium to the patient’s plasma, triggering coagulation and allowing for the optical measurement of clot formation in the high molecular weight kininogen assay.
10. The high molecular weight kininogen assay is performed to assess the presence of Fitzgerald factor in a patient’s plasma, aiding in the investigation of a prolonged PTT test when other clotting factor tests are normal.