Coding corner update: Improve medical record documentation for chronic kidney disease

Beginning Oct. 1, 2015, the transition to ICD-10-CM will affect every area of health care. Many codes contain much greater specificity. This article includes updated codes to align with the transition to ICD-10-CM.

The complex nature of chronic kidney disease makes accurate code selection essential. A basic understanding of chronic kidney disease, its causes and its comorbidities can help you assign the highest possible specificity of codes.

Chronic kidney disease is a condition characterized by a gradual loss of kidney function. When kidney disease gets worse, the kidney cells called nephrons that filter out wastes and other fluids from the bloodstream lose the ability to filter, causing the kidneys to lose functionality.

Complications of chronic kidney disease include high blood pressure, anemia, weak bones and nerve damage. It may also increase the risk of developing heart or blood vessel disease.

ICD-10-CM codes are based on the severity of chronic kidney disease. The provider must clearly document the stage to ensure codes are chosen to the highest level of specificity. Coders can’t assign a code based on glomerular filtration rate alone and should be as specific as possible:

Chronic kidney disease and diabetes
If the patient has chronic kidney disease caused by diabetes, the code for diabetes would be assigned first according to the conventions in the tabular list.

• Assign E08.22, E09.22, E10.22, E11.22 or E13.22 to identify the correct type of diabetes, followed by the appropriate chronic kidney disease code from the N18 category.
• Documentation must show causality between the two conditions. For example, diabetic nephropathy or CKD due to diabetes.
• Although the word “with” is considered acceptable linkage within the context of the ICD-10-CM, BCBSM does not consider the word “with” to be an acceptable linking word in provider documentation.

Chronic kidney disease and anemia
When chronic kidney disease is present, the kidneys may not make enough erythropoietin, a hormone that controls red blood cell production. This may cause anemia to develop. When documentation indicates the link between the two conditions, assign a code from category N18 first to indicate the stage of the chronic kidney disease and code D63.1 Anemia in CKD.

Chronic kidney disease and hypertension
ICD-10-CM presumes a cause-and-effect relationship, and classifies chronic kidney disease with hypertension as Hypertensive CKD whether or not it’s documented. So, when it’s present with hypertension, assign codes from category I12.-, Hypertensive CKD.

• Assign a fourth character for hypertensive CKD, I12.-, based on the stage of the chronic kidney disease
• Use an additional code to identify the stage of chronic kidney disease (N18.-)

(Note: - are used rather than Xs, as an X may be used as part of a valid code.)

Hypertensive heart and chronic kidney disease
Report hypertensive heart and chronic kidney disease with a code from the combination category code I13 when both conditions are stated in the diagnosis. The relationship between the hypertension and chronic kidney disease is still assumed, but heart disease and chronic kidney disease don’t have an assumed relationship. Documentation must state a cause-and-effect relationship.

• Assign a fourth character for hypertensive heart and CKD, I13.-, based on the stage of the chronic kidney disease.
• Also use additional codes to identify the stage of chronic kidney disease (N18.-) and to code the specific type of heart failure (I50.-), if known.

Coding kidney dialysis and transplants
Early detection and treatment can often keep chronic kidney disease from getting worse, but when kidney disease progresses it can lead to kidney failure which often requires dialysis or a kidney transplant to maintain life.

• If the patient is admitted solely for dialysis treatment, use the code to describe the condition for which the patient is having dialysis and then Z99.2 (dependence on renal dialysis). Report Z91.15 for patients who are noncompliant with renal dialysis.
• Patients who have undergone a kidney transplant may still have chronic kidney disease. A kidney transplant doesn’t always restore full kidney function.
• Assign the appropriate chronic kidney disease code (N18) for the patient’s stage followed by code Z94.0.0, kidney transplant status.
• Kidney transplant complication codes are only assigned if the complication affects the function of the transplanted organ.
• Two codes may be required to fully describe a transplant rejection or transplant complication. Use code T86.1- and a secondary code that identifies the complication if appropriate.

ICD-10-CM coding for all conditions should follow coding conventions, chapter specific guidelines and general coding guidelines.

If you have questions or need more information, contact your provider consultant.

None of the information included in this article is intended to be legal advice and, as such, it remains the provider’s responsibility to ensure that all coding and documentation are done in accordance with applicable state and federal laws and regulations.