Anesthesia Coding Alert

Comprehend which HTN cases call for the use of a combination code.

In Anesthesia Coding Alert Volume 26, Number 3, you learned all about blood pressure categories as well as the definitions and rules that impact coding. This issue will provide further insight into reporting HTN and the various diseases that may be associated with high blood pressure.

Here are some more fast facts to keep your hypertension coding in tip-top shape.

Know Uncontrolled HTN Can Cause Other Diseases

Hypertension occurs when the force/pressure of the blood against the arterial walls is too high, says Julie-Leah J. Harding, CPC, CPMA, CEMC, CCC, CRC, RMC, PCA, CCP, SCP-ED, CDIS, AHIMA-approved ICD-10 trainer and ambassador and director of clinical compliance-cardiovascular surgery at Boston Children’s Hospital in Boston, Massachusetts. Early detection and proper management of HTN are crucial, as chronically elevated blood pressure can increase the chances that heart, brain, kidney, and other diseases may arise.

Code Hypertensive Heart Disease Like This

If the documentation indicates the patient has hypertensive heart disease — HTN that has resulted in a heart condition classified under I50.- (Heart failure), I51.4 (Myocarditis, unspecified)-I51.7 (Cardiomegaly), I51.89 (Other ill-defined heart diseases), or I51.9 (Heart disease, unspecified) — report the appropriate code from category I11.- (Hypertensive heart disease), according to the ICD-10-CM guidelines:

• I11.0 (Hypertensive heart disease with heart failure); includes hypertensive heart failure
• I11.9 (Hypertensive heart disease without heart failure); includes hypertensive heart disease not otherwise specified (NOS)

Coding tip: Pay close attention to the multiple “code also” and “use additional code notes” for hypertension. If the patient has heart failure, be sure to report an additional code from category I50.- to identify the exact type of heart failure. Possible options include I50.22 (Chronic systolic (congestive) heart failure), I50.32 (Chronic diastolic (congestive) heart failure), and I50.814 (Right heart failure due to left heart failure).

However, if the physician documents that the heart condition (I50.-, I51.4-I51.7, I51.89, I51.9) is not related to the patient’s HTN, instead report those conditions separately and sequence according to the circumstances of the encounter.

Remember To Report CKD Stage for Hypertensive CKD

If the provider documentation indicates that the patient has hypertensive chronic kidney disease (CKD) — HTN that has resulted in a renal condition that falls under category N18.- (Chronic kidney disease (CKD)), submit the appropriate combination code from category I12.- (Hypertensive chronic kidney disease) instead of using two separate codes.

On the other hand, you should not code CKD as hypertensive if the provider indicates the kidney disease is not related to the hypertension, according to the guidelines.

Secondary code: When you use a code from category I12.-, you should also report a secondary code from category N18.- to indicate the stage of CKD, which correlates to disease severity:

• Stage 1: N18.1 (Chronic kidney disease, stage 1)
• Stage 2: N18.2 (Chronic kidney disease, stage 2 (mild))
• Stage 3: N18.3- (Chronic kidney disease, stage 3 (moderate))
  • N18.30 (… stage 3 unspecified)
  • N18.31 (… stage 3a)
  • N18.32 (… stage 3b)
• Stage 4: N18.4 (Chronic kidney disease, stage 4 (severe))
• Stage 5: N18.5 (Chronic kidney disease, stage 5)
• End-stage renal disease (ESRD): N18.6 (End stage renal disease)

In the early stages (stages 1–3), the kidneys are still able to filter waste out of the blood. In the later stages (stages 4–5), the patient’s kidneys must work harder to filter their blood and may stop working altogether.

Coding tip: “If both a stage of CKD and ESRD are documented, assign code N18.6 only,” per guideline I.C.14.a.1.

Look To Category I13.- Codes for Hypertensive Heart and CKD

If the patient has hypertension with both heart and kidney involvement, report a code from category I13.- (Hypertensive heart and chronic kidney disease). If your provider documents the presence of heart failure, be sure to include the appropriate code from category I50.- to identify the exact type of heart failure.

Don’t miss: When using a code from category I13.-, you must also report the appropriate code from category N18.- as a secondary code to identify the stage of CKD, per the guidelines.

Coding tip: Category II3.- is a combination category for hypertensive heart and CKD. If a patient has all three conditions, hypertension, heart disease, and CKD, report a code from category I13.-. Do not submit individual codes for hypertension, heart disease, and CKD, or codes from categories I11.- or I12.-.

If the patient has both acute renal failure and CKD, you should also document the appropriate code for acute renal failure and sequence according to the circumstances of the encounter.

“In order for the coder to be able to collect the details needed for selecting the correct codes for hypertension, the provider must document if the patient has congestive heart failure and/ or kidney disease,” says Carol Hodge, CPC, CPMA, CDEO, CCC, CEMC, CPB, CFPC, COBGC, senior documentation specialist at St. Joseph’s/Candler Medical Group. “If so, then the provider needs to document the type of heart failure and/or the stage of kidney disease.”

Key: Code these conditions as related even in the absence of provider notes explicitly linking them unless the documentation clearly states the conditions are unrelated.