Q&A: Querying antibiotic resistance

April 27, 2023

CDI Strategies - Volume 17, Issue 17

Q: When we open sensitivity reports, there are all sorts of antibiotic resistances with organisms, some cultures have one “resistant” listed while others have multiple. Do you have any guidance as to when we should query for the resistance? If a patient with a positive culture (wound, urine, etc.) has multiple resistant antibiotics, when is it appropriate to query for antibiotic resistance (Z16.20, unspecified antibiotic, or Z16.29, single specified antibiotic) versus listing individual antibiotic resistance (e.g., amoxicillin, quinolone, or cephalosporin drug resistance)?

A: Antibiotic resistance is a term used to describe the ability of bacteria to resist the effects of antibiotics. This means that the bacteria are no longer sensitive to the antibiotics that would normally be used to kill them, making it more difficult to treat infections caused by those bacteria. Antibiotic resistance can arise through a variety of mechanisms, including genetic mutations or acquisition of resistance genes from other bacteria.

Antibiotic resistance is a growing problem worldwide as the overuse and misuse of antibiotics has led to the development of increasingly resistant strains of bacteria. It is important to use antibiotics appropriately and only when necessary to help prevent the emergence and spread of antibiotic-resistant bacteria.

When a laboratory report lists a bacterium as having resistance or sensitivity to a particular antibiotic, it alerts the provider to evaluate appropriate treatment options for the patient. The interpretation of laboratory results and the appropriate treatment of infections should be made by a healthcare professional who takes into consideration the specific circumstances of the patient's case, including their medical history and any other relevant factors.

If a laboratory report shows that a patient has a multi-resistant organism (MRO), it is important for the healthcare provider to be informed so that appropriate measures can be taken to manage the infection and prevent its spread.

In some cases, the healthcare provider may need to modify the patient's treatment plan to address the resistance of the organism, such as by choosing a different antibiotic or combination of antibiotics that are effective against the organism. It’s also important to take appropriate infection control measures to prevent the spread of the organism to other patients, staff, and visitors. The healthcare provider may need to communicate with other healthcare professionals involved in the patient's care to ensure that everyone is aware of the presence of the multi-resistant organism and that appropriate precautions are taken.

An MRO is a type of bacteria that has developed resistance to multiple antibiotics, making it more difficult to treat infections caused by these bacteria. Multi-resistance can develop through several mechanisms, including genetic mutations or acquisition of resistance genes from other bacteria. MROs are a growing concern in healthcare settings, as they can cause serious infections that are difficult to treat and may spread rapidly. Common examples of MROs include methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and carbapenem-resistant Enterobacteriaceae.

Preventing the spread of MROs is essential to prevent infections and protect public health. In healthcare settings, infection control measures such as hand hygiene, isolation precautions, and appropriate use of antibiotics can help reduce the spread of MROs.

For reporting purposes, we look to the following ICD-10-CM Official Guidelines for Coding and Reporting:

Section I.B.19.d. Use of Z codes
Z codes (other reasons for healthcare encounters) may be assigned as appropriate to further explain the reasons for presenting for healthcare services, including transfers between healthcare facilities, or provide additional information relevant to a patient encounter. The ICD-10-CM Official Guidelines for Coding and Reporting identify which codes may be assigned as principal or first-listed diagnosis only, secondary diagnosis only, or principal/first-listed or secondary (depending on the circumstances) […] Assign as many codes as necessary to fully explain each healthcare encounter. Since patient history information may be very limited, use any available documentation to assign the appropriate external cause of morbidity and Z codes.

Section I.C.21.c.3. Z16, Resistance to antimicrobial drugs
This code indicates that a patient has a condition that is resistant to antimicrobial drug treatment. Sequence the infection code first.

Section III.B.
Abnormal findings (laboratory, x-ray, pathologic, and other diagnostic results) are not coded and reported unless the provider indicates their clinical significance. If the findings are outside the normal range and the attending provider has ordered other tests to evaluate the condition or prescribed treatment, it is appropriate to ask the provider whether the abnormal finding should be added.

Section I.C.1.c.
Many bacterial infections are resistant to current antibiotics. It is necessary to identify all infections documented as antibiotic resistant. Assign a code from category Z16, Resistance to antimicrobial drugs, following the infection code only if the infection code does not identify drug resistance.

In this situation, a query should be posed to the provider to inquire on the clinical significance of the laboratory findings. If there is multiple drug resistance, the query may include multi-drug resistant organisms (MDRO) as an acceptable choice. The codes from category Z16 are comorbid conditions and should be reported if clinically relevant.

Here is an example of an acceptable query in relation to this question:

Dear Dr. XX,

The patient’s laboratory results reflect organism resistance to Amoxicillin, cefazolin, and gentamicin. Please document within the patient’s medical record the relevancy of these clinical findings.

Organism drug resistance to (document each specific drug)
Multi-Drug Resistant Organism (MDRO)
Other (Please specify)
Not clinically significant

You may also find the following resources helpful in relation to drug resistant organisms:

Editor’s note: Deanne Wilk, MPS, BSN, RN, CCDS, CCDS-O, CDIP, CCS, CDI education specialist for ACDIS/HCPro based in Middleton, Massachusetts, answered this question. Contact her at dwilk@hcpro.com.

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