Question: A patient has hypertension, chronic kidney disease, renal failure, and is currently on dialysis. Patient is a former smoker who quit 3 years ago. Assign the ICD-10-CM codes.

Answer:

I12.0, N18.6, Z99.2, Z87.891

Hypertension, otherwise known as high blood pressure, is a leading cause of chronic kidney disease (CKD), according to kidney.org. Hypertension can eventually damage the blood vessels and reduce the blood supply to the kidneys and other important organs. Eventually, CKD may lead to kidney failure and necessitate a kidney transplant or dialysis to maintain life.

Hypertension can also be a complication of CKD, as the kidneys play a major role in keeping the blood pressure under control. If the diseased kidneys are not able to keep the blood pressure under control, the blood pressure increases.

According to the 2021 ICD-10-CM Coding Guidelines, the coder may assume a causal relationship between hypertension and kidney involvement, because the two conditions are linked by the term “with” in the Alphabetic Index. Even if the documentation does not specifically state that the two conditions are related, we can and should code them as related unless the documentation clearly states the conditions are unrelated.

For hypertension and conditions not specifically linked by relational terms such as “with,” “associated with” or “due to” in the classification, provider documentation must link the conditions in order to code them as related.

The coding guidelines also state, “Assign codes from category I12, Hypertensive chronic kidney disease, when both hypertension and a condition classifiable to category N18, Chronic kidney disease (CKD), are present. CKD should not be coded as hypertensive if the provider indicates the CKD is not related to the hypertension. The appropriate code from category N18 should be used as a secondary code with a code from category I12 to identify the stage of chronic kidney disease… If a patient has hypertensive chronic kidney disease and acute renal failure, the acute renal failure should also be coded.”

If a patient with CKD also suffers from other serious conditions, such as diabetes mellitus and hypertension, sequencing of the CKD code in relationship to codes for other contributing conditions is based on the coding conventions in the Tabular List.

Locate and Verify

When looking up Hypertension in the Alphabetic Index, see Hypertension, with, kidney involvement, it tells us to go to Hypertension, kidney, with, stage 5 chronic kidney disease (CKD) or end stage renal disease (ESRD) I12.0.

In the Tabular, we can verify this code as:

I12.0, Hypertensive chronic kidney disease with stage 5 chronic kidney disease or end stage renal disease

There are only two codes listed under category I12, Hypertensive chronic kidney disease:

  • I12.0, Hypertensive chronic kidney disease with stage 5 chronic kidney disease or end stage renal disease
  • I12.9, Hypertensive chronic kidney disease with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease

There is a note under I12.0 that states “Use additional code to identify the stage of chronic kidney disease (N18.5, N18.6).”

In ICD-10-CM, CKD is classified based on severity, which are designated by stages 1-5:

  • N18.1, Chronic kidney disease, stage 1
  • N18.2, Chronic kidney disease, stage 2 (mild)
  • N18.30, N18.32   N18.3, Chronic kidney disease, stage 3 (moderate)
  • N18.4, Chronic kidney disease, stage 4 (severe)
  • N18.5, Chronic kidney disease, stage 5
  • N18.6, End stage renal disease (ESRD)
  • N18.9, Chronic kidney disease, unspecified

Per the coding guidelines, “If both a stage of CKD and ESRD are documented, assign code N18.6 only.” Hence, our code here is:

N18.6, end stage renal disease

A synonym listed under N18.6, End stage renal disease, is Chronic kidney disease requiring chronic dialysis.

There is a note at N18 that states, “Code First any associated hypertensive chronic kidney disease (I12.-, I13.-).” This tells us that the Hypertensive CKD (I12.0) needs to be sequenced first, followed by the End stage renal disease (N18.6).

There is a note at N18.6 that states “Use additional code to identify dialysis status (Z99.2).” The documentation indicates the patient is on dialysis, so this code needs to be assigned after N18.6 as:

Z99.2, Dependence on renal dialysis

Other synonyms listed under Z99.2, Dependence on renal dialysis are:

  • Hemodialysis status
  • Peritoneal dialysis status
  • Presence of arteriovenous shunt for dialysis
  • Renal dialysis status NOS

There is also a note at I10-I16 that indicates the following should be assigned, as applicable:

  • exposure to environmental tobacco smoke (Z77.22)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)

Patient is a former smoker, according to the documentation; therefore, we need to assign:

Z87.891, Personal history of nicotine dependence

As always, it’s critical that all guidelines and conventions are reviewed before making final code selection.


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