How To Use CPT Code 87186

CPT 87186 is a code for susceptibility studies of antimicrobial agents using microdilution or agar dilution methods. This article will cover the description, procedure, qualifying circumstances, usage, documentation requirements, billing guidelines, historical information, similar codes, and examples of CPT 87186.

1. What is CPT 87186?

CPT 87186 is a code used to describe the laboratory procedure of susceptibility studies for antimicrobial agents, specifically using microdilution or agar dilution methods. These studies help determine the minimum inhibitory concentration (MIC) or breakpoint of each antimicrobial agent, which aids clinicians in selecting the appropriate antibiotic and dosage level to treat an infection caused by the isolated organism.

2. 87186 CPT code description

The official description of CPT code 87186 is: “Susceptibility studies, antimicrobial agent; microdilution or agar dilution (minimum inhibitory concentration [MIC] or breakpoint), each multi-antimicrobial, per plate.”

3. Procedure

The procedure for CPT 87186 involves the following steps:

1. A culture isolate is obtained from the patient and specifically identified as an organism, such as a bacterium.
2. The lab analyst prepares a standard concentration of the original culture isolate and uses a specific amount to inoculate test wells.
3. A test plate is set up in a grid of test wells containing agar or other media with different antibiotics at different concentrations.
4. The plate is incubated for a specific time under controlled conditions.
5. The lab analyst observes the test wells and notes the lowest concentration of each antibiotic that inhibited culture growth, reporting the findings as the minimum inhibitory concentration (MIC) for each antibiotic.
6. Each plate with multiple antimicrobial agents represents one unit of 87186.

4. Qualifying circumstances

Patients eligible to receive CPT code 87186 services are those with infections caused by organisms that require susceptibility testing to determine the appropriate antibiotic and dosage level for treatment. This may include patients with critical infections such as bacteremia and endocarditis, where the test’s importance in guiding therapy is crucial.

5. When to use CPT code 87186

CPT code 87186 should be used when a clinician orders susceptibility studies using microdilution or agar dilution methods to determine the minimum inhibitory concentration (MIC) or breakpoint of each antimicrobial agent. This information is essential for selecting the appropriate antibiotic and dosage level to treat an infection caused by the isolated organism.

6. Documentation requirements

Documentation supporting a claim for CPT 87186 should include:

• A detailed description of the procedure performed, including the specific method used (microdilution or agar dilution).
• The results of the susceptibility studies, including the MIC or breakpoint for each antimicrobial agent tested.
• A clear indication of the clinical necessity for the test, such as the patient’s diagnosis and the rationale for selecting the specific antibiotics tested.
• Any relevant patient history or clinical findings that support the need for susceptibility testing.

7. Billing guidelines

When billing for CPT code 87186, it is essential to ensure that the documentation supports the medical necessity of the test and that the procedure is performed using the appropriate method (microdilution or agar dilution). Additionally, it is crucial to differentiate CPT 87186 from other susceptibility study methods described by codes 87181 to 87185 and +87187 to 87190.

8. Historical information

CPT 87186 was added to the Current Procedural Terminology system on January 1, 1990. The code has undergone changes since its addition:

• Code Changed on 01-01-2001: Sensitivity studies, antibiotic; microtiter, minimum inhibitory concentration (MIC), any number of antibiotics.
• Code Changed on 01-01-2009: Susceptibility studies, antimicrobial agent; microdilution or agar dilution (minimum inhibitory concentration (MIC) or breakpoint), each multi-antimicrobial, per plate.

9. Similar codes to CPT 87186

Five similar codes to CPT 87186 and how they differentiate from CPT 87186 are:

1. CPT 87181: This code is used for susceptibility studies using the disk method.
2. CPT 87182: This code is used for susceptibility studies using the gradient diffusion method.
3. CPT 87183: This code is used for susceptibility studies using the serial dilution method.
4. CPT 87184: This code is used for susceptibility studies using the agar screen method.
5. CPT 87185: This code is used for susceptibility studies using the automated method.

10. Examples

Here are 10 detailed examples of CPT code 87186 procedures:

1. A patient with a urinary tract infection caused by Escherichia coli requires susceptibility testing to determine the appropriate antibiotic treatment.
2. A patient with pneumonia caused by Streptococcus pneumoniae requires susceptibility testing to guide antibiotic therapy.
3. A patient with a skin infection caused by Staphylococcus aureus requires susceptibility testing to determine the most effective antibiotic treatment.
4. A patient with a bloodstream infection caused by Klebsiella pneumoniae requires susceptibility testing to select the appropriate antibiotic therapy.
5. A patient with meningitis caused by Neisseria meningitidis requires susceptibility testing to guide the choice of antibiotic treatment.
6. A patient with an intra-abdominal infection caused by Bacteroides fragilis requires susceptibility testing to determine the most effective antibiotic therapy.
7. A patient with a bone infection caused by Pseudomonas aeruginosa requires susceptibility testing to guide the selection of antibiotic treatment.
8. A patient with a respiratory infection caused by Haemophilus influenzae requires susceptibility testing to determine the appropriate antibiotic therapy.
9. A patient with a wound infection caused by Enterococcus faecalis requires susceptibility testing to guide the choice of antibiotic treatment.
10. A patient with an ear infection caused by Moraxella catarrhalis requires susceptibility testing to determine the most effective antibiotic therapy.