How To Use CPT Code 87188

CPT 87188 describes the macrobroth dilution method used to evaluate the susceptibility of a culture isolate to multiple antimicrobial agents. 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 87188?

CPT 87188 can be used to describe the macrobroth dilution method used to evaluate the susceptibility of a culture isolate to multiple antimicrobial agents. This code is used when a lab analyst observes the growth of the isolate in various concentrations of each antibiotic using macrobroth dilution methods.

2. Official Description

The official description of CPT code 87188 is: ‘Susceptibility studies, antimicrobial agent; macrobroth dilution method, each agent.’

3. Procedure

1. The lab analyst prepares a standard concentration of the culture isolate and inoculates tubes containing nutrient broth with different antibiotics at different concentrations.
2. The tubes are incubated under controlled conditions for a specific time.
3. The lab analyst observes the tubes for cloudiness and notes the lowest concentration of each antibiotic that inhibits culture growth.
4. The lab analyst reports the findings as the minimum inhibitory concentration (MIC) for each antibiotic.

4. Qualifying circumstances

CPT 87188 is ordered by clinicians to aid in the selection of an appropriate antibiotic and dosage level to treat an infection of the isolated organism. The test is typically ordered for critical infections such as bacteremia and endocarditis.

5. When to use CPT code 87188

CPT code 87188 should be used when the macrobroth dilution method is used to evaluate the susceptibility of a culture isolate to multiple antimicrobial agents. It should not be used for other susceptibility study methods described by different codes.

6. Documentation requirements

To support a claim for CPT 87188, the lab analyst must document the following information:

• Specific antimicrobial agents tested
• Minimum inhibitory concentration (MIC) for each antibiotic
• Interpretation of the result into susceptibility categories (S, I, R)

7. Billing guidelines

When billing for CPT 87188, ensure that the macrobroth dilution method is used to evaluate the susceptibility of a culture isolate to multiple antimicrobial agents. There are no specific guidelines regarding reporting with other codes.

8. Historical information

CPT 87188 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 performing the macrobroth dilution method to evaluate the susceptibility of a culture isolate to multiple antimicrobial agents.
2. A clinician ordering CPT 87188 to aid in the selection of an appropriate antibiotic and dosage level for a patient with a critical infection.
3. A lab reporting the minimum inhibitory concentration (MIC) for each antibiotic tested using the macrobroth dilution method.
4. A clinician interpreting the susceptibility result into categories (S, I, R) based on the macrobroth dilution method.
5. A lab analyst documenting the specific antimicrobial agents tested and their corresponding MIC values.
6. A clinician using the results of CPT 87188 to decide which drug and dosage is most likely to effectively treat a patient’s infection.
7. A lab analyst performing the macrobroth dilution method for a culture isolate obtained from a patient with endocarditis.
8. A clinician ordering CPT 87188 to guide therapy for a patient with bacteremia.
9. A lab reporting the susceptibility result as ‘S’ for an antibiotic tested using the macrobroth dilution method.
10. A clinician considering the MIC values reported for each antibiotic when selecting the appropriate treatment for a patient’s infection.