How To Use CPT Code 84450

CPT 84450 describes the quantitation of the enzyme aspartate amino transferase (AST), also known as SGOT, using serum or plasma samples. 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 84450?

CPT 84450 is used to measure the levels of the enzyme aspartate amino transferase (AST), also known as SGOT, in serum or plasma samples. AST is primarily found in the liver, but it is also present in other tissues such as the heart and muscles. Elevated AST levels can indicate various clinical conditions, including liver disease, muscle disease, renal disease, and myocardial infarction.

2. Official Description

The official description of CPT code 84450 is: ‘Transferase; aspartate amino (AST) (SGOT).’ This code is used to quantitate the levels of AST in serum or plasma samples using laboratory chemistry analyzers.

3. Procedure

1. The lab analyst performs the technical steps of the AST test, typically using serum or plasma samples.
2. The samples are placed on automated instruments, and the analyst ensures the proper functioning of the analyzer.
3. The analyzer measures the levels of AST in the samples using a kinetic or enzymatic rate method.
4. The method involves two measurements of the color change caused by AST enzymatically degrading a substance.
5. The degree of color change indicates the amount of AST present in the sample.

4. Qualifying circumstances

CPT 84450 is used when measuring AST levels in serum or plasma samples to assess various clinical conditions. These conditions may include liver disease, muscle disease, renal disease, and myocardial infarction. The test is performed by a lab analyst using laboratory chemistry analyzers.

5. When to use CPT code 84450

CPT code 84450 should be used when there is a need to quantitate the levels of AST in serum or plasma samples. This test is appropriate when evaluating patients with suspected liver disease, muscle disease, renal disease, or myocardial infarction. It is important to note that CPT code 84450 should not be used for other enzyme tests or when measuring AST levels in other sample types.

6. Documentation requirements

To support a claim for CPT code 84450, the documentation should include:

• Patient’s clinical condition and the reason for performing the AST test
• Type of sample used (serum or plasma)
• Date and time of the test
• Results of the AST test
• Signature of the lab analyst performing the test

7. Billing guidelines

When billing for CPT code 84450, ensure that the test is performed by a lab analyst using serum or plasma samples. It is important to follow the specific guidelines provided by the payer regarding the appropriate use of this code. Additionally, consider any applicable modifiers or additional codes that may be required for accurate billing.

8. Historical information

CPT code 84450 was added to the Current Procedural Terminology system on January 1, 1990. There have been no updates or changes to this code since its addition.

9. Examples

1. A patient with suspected liver disease undergoes an AST test to assess liver function.
2. An individual who experienced chest pain is tested for AST levels to evaluate the possibility of a myocardial infarction.
3. A patient with muscle weakness undergoes an AST test to assess muscle function and detect any potential muscle disease.
4. An individual with renal disease undergoes an AST test to monitor kidney function and assess any potential liver involvement.
5. A patient with elevated AST levels in a previous test undergoes a follow-up AST test to monitor their condition and assess treatment effectiveness.