By Lori O’Hara, CCC-SLP, Skilled Reimbursement Resource
What a wonderful thing our immune system is! We each have our own little army ready and willing to fight off invasions of viruses or bacteria at a moment’s notice. But for some folks, the army isn’t anywhere near as large as it needs to be, or the orders get muddled up somehow and it can’t fight at its best. It’s important to know who those patients are and how to best try and protect them when their immune system army can’t do it alone.
According to the Merck Manual, 2023, “Immunodeficiency disorders involve malfunction of the immune system, resulting in infections that develop and recur more frequently, are more severe, and last longer than usual.”
Immunodeficiency present at birth due to a genetic disorder is called primary immunodeficiency. Immunodeficiency that is acquired later due to a disease, a drug, or exposure to something that compromises the immune system (like radiation) is called secondary immunodeficiency. Both types of immunodeficiency are included as PDPM components, but secondary immunodeficiency is much more common.
Patients who have primary immunodeficiency or secondary immunodeficiency due to an immune system disease (such as HIV or lupus) are likely to already be diagnosed as such when they come to us. But secondary immunodeficiency can develop due to quite a few diseases that aren’t themselves immune system diseases. Additionally, some common treatments we see can themselves suppress the immune response.
Detecting and Confirming Immunodeficiency Status
While everyone is susceptible to an infection now and then, individuals with immunodeficiency struggle with recurrent infections, resistant infections, and slow recovery from injuries or illnesses. Seeing these problems noted in a patient’s history should put you on alert. Then, if you see that those problems exist in the context of a condition that is known to cause immunodeficiency, you have cause to act.
In order to query a physician about immunodeficiency status, two circumstances must be present:
Conditions That Can Cause Immune Deficiency Signs That the Immune System Might Be Deficient Related to an Active Disease Process
● Diabetes with sustained hyperglycemia (A1C greater than or equal to 8%)
● Chronic kidney disease , especially with dialysis-dependent patients
● Advanced liver disease
● Absence of spleen
● COPD , most notably with inhaled corticosteroid treatment
● Prolonged use of high-dose corticosteroids (>20 mg per day)
● Prolonged use of immunosuppressant therapies
● Prolonged moderate to severe protein calorie malnutrition, typically diagnosed prior to transfer ● Recurrent infections
● Drug-resistant infections
● Prolonged or difficult-to-resolve infections
● Slow-healing wounds
● Poor vaccination response
● Oral sores and advanced gum disease
● Unusual fungal infections/thrush
● Chronic diarrhea and poor appetite
● Fever and chills
● Weight loss
When you have ample evidence that the condition exists because you have both the conditions and the signs, then you can start a conversation with the provider about whether or not adding a diagnosis is appropriate.
Additionally, immunodeficiency may be presumed to exist — even without secondary signs — in some circumstances. When a condition is very advanced or very poorly controlled (for example, diabetes, liver failure, or chronic kidney disease), or with some medical treatments that aggressively target the immune system (like chemotherapy or radiation), the provider may establish that the condition exists regardless of the presence of the signs of deficiency detailed above.
Selecting a Diagnosis and the PDPM Impact
If the disease is a disorder of the immune system (like neutropenia), or immune system involvement is inherent to the condition, you won’t code anything more than the disease itself. But when the immunodeficiency is a manifestation of another disease or treatment, then you’d typically consider one of the following diagnoses:
D84.81 Immunodeficiency due to conditions classified elsewhere
Use when a non-immune disease — like diabetes — is causing immunodeficiency.
D84.821 Immunodeficiency due to drugs
Use when drugs or medications — like corticosteroids, immunosuppressants, or chemotherapy — are causing immunodeficiency.
D84.822 Immunodeficiency due to external causes
Use when radiation treatment or ionizing radiation exposure has caused immunodeficiency.
D84.89 Other Immunodeficiencies (Use when the cause of immunodeficiency doesn’t fit any of the other three categories.)
Pro Tip! Always remember that when you add a diagnosis that is “due to,” then it should be immediately preceded by the causal condition in the diagnosis list when the condition still exists.
There are two categories of immune conditions in the NTA case mix. One includes principally the genetic immune disorders, and the other includes the conditions related to the cellular component of the immune response. Because the NTAs are ICD-10 dependent, the NTA will only trigger if an included diagnosis is present. As coding rules will prohibit us from coding the “due to” conditions when the cause is an immune disorder itself, it’s almost impossible to trigger both categories (unless the patient truly has a medical condition from each category, which will be very rare).
Remember that coding rules require us to diagnose accurately, and it is improper to select a more advantageous diagnosis if it isn’t supported. If an immune disorder is present but not included in the diagnosis list for an NTA, we must still code the condition accurately. Because these conditions increase reimbursement, we must be diligent and accurate in their identification.
Finally, remember the query rules: Explain exactly why you think the condition is present, citing your sources in the medical record. Make sure the physician has options to choose from and can add something different, or select “none” when responding to your request. See “Avoiding the Query Quandary” for more help.
Immunodeficiency Vs. Autoimmune Disease
While immunodeficiency and autoimmune disease can correlate, patients with autoimmune diseases (e.g., Hashimoto’s thyroiditis, rheumatoid arthritis, MS, Crohn’s disease) are generally not automatically presumed to be immunodeficient. However, the treatments used to manage them can sometimes cause immunodeficiency, and some autoimmune diseases are more likely to affect the immune system than others (or eventually progress to involving the immune system as they advance). So when you see the markers of immunodeficiency in the presence of significant autoimmune disease or in the presence of aggressive or long-term immunosuppressant or steroid use, tell the provider what you’re seeing and ask them to weigh in.
Is It Active?
As with all conditions that are part of Section I of the MDS, we must not only have a provider confirm that the condition has been present in the 60-day lookback. We must also be able to show that the condition has had a direct relationship to the patient’s functional status, cognitive status, mood or behavior status, medical treatments, nursing monitoring, or risk of death in the last seven days.
The following management may be ordered by a provider or established as nursing measures to support a patient whose immune system is compromised:
Management of an active infection
Elevated infection monitoring
o Laboratory monitoring
o Individualized parameters for vital signs + every six-hour vitals
Laboratory monitoring immediately post infection
Laboratory screening for immune status markers (e.g., white blood cell count, neutrophil count, kidney function, protein levels)
Decreasing exposure to possible infection
o Maintaining isolation status (note that this may or may not meet the MDS requirements for coding isolation)
o Prohibiting group environments (dining, therapy, large activities)
o Utilizing enhanced barrier precautions (making sure to document and care-plan that the EBP is to decrease exposure to infection, not the transmission of infection)
Immunization review
o Vaccination history review and education
o Vaccination administration and updates
Incentive spirometry for individuals at elevated risk for respiratory infection (note that IS for this reason alone does not satisfy the requirements to report minutes as respiratory therapy in the MDS)
Immunocompromised/immunodeficient patients are typically at greater risk immediately following a hospitalization. Illnesses that impact metabolism or nutritional uptake, multiple skin-penetrating procedures and treatments, use of catheters, and the general increase in environmental exposure to bacteria in a hospital create a period of elevated vulnerability. A provider may determine that the measures above are appropriate in the first few weeks after a hospitalization but then decide that it’s appropriate to taper these precautions down or discharge them entirely over time.
Special thanks to Dr. Pouya Afshar and MDS Resource Jesi Martin for their contributions to this newsletter!
Berbudi A, Rahmadika N, Tjahjadi AI, Ruslami R. Type 2 Diabetes and its Impact on the Immune System. Curr Diabetes Rev. 2020;16(5):442-449. doi:10.2174/1573399815666191024085838
Steiger S, Rossaint J, Zarbock A, Anders HJ. Secondary Immunodeficiency Related to Kidney Disease (SIDKD)-Definition, Unmet Need, and Mechanisms. J Am Soc Nephrol. 2022 Feb;33(2):259-278. doi: 10.1681/ASN.2021091257. Epub 2021 Dec 14. PMID: 34907031; PMCID: PMC8819985.
Albillos, A., Martin-Mateos, R., Van der Merwe, S. et al. Cirrhosis-associated immune dysfunction. Nat Rev Gastroenterol Hepatol 19, 112–134 (2022). https://doi.org/10.1038/s41575-021-00520-7
Palikhe, N.S., Niven, M., Fuhr, D. et al. Low immunoglobulin levels affect the course of COPD in hospitalized patients. Allergy Asthma Clin Immunol 19, 10 (2023). https://doi.org/10.1186/s13223-023-00762-x
Commentaires