Coding arterial ulcers

When the supply of blood to an area of the body is not sufficient, the result is a shortage of oxygen and glucose needed for cellular metabolism.
The medical term for this condition is ischemia. The blood flow problem may be due to narrowing of the arteries by spasm or disease – or by some other form of arterial obstruction, such as pressure or trauma.
Some serious health risks, including stroke, are associated with insufficient blood supply, depending upon where in the body the blood flow is restricted.
When blood does not flow adequately to the capillary beds of the lower extremities, one of the most painful results may be an ischemic, or arterial, ulcer.
These ulcers typically present on the lower leg or foot, particularly on the sides of the foot or the tips of a patient’s toes, where there is inadequate perfusion of skin and subcutaneous tissue.
Clinicians generally recognize arterial ulcers by their “punched out” appearance. They are full thickness wounds with smooth edges.
The appearance of the ulcer with regard to shearing and stretching of the tissue, whether dead tissue is sloughing off or whether there is eschar, a black tissue that can create a hard shell over an ulcer, is important to properly code an arterial ulcer. This is because ICD-10 classification requires documentation of the severity of the ulcer, even in the absence of documentation from the physician. We’ll  take a look at the general stages of severity later in this article.

Causes and relationships
     It is also important to note the underlying condition when coding arterial ulcers. Circulation problems which lead to ischemic, or arterial, ulcers may be caused by conditions such as coronary disease, artery disease, diabetes mellitus, hypertension, hyperlipidemia, Peripheral Artery Disease (PAD) or smoking.
The prevalence of arterial insufficiency ulcers among people with diabetes is particularly high due to decreased blood flow caused by the thinning of arteries. A lack of sensation due to diabetic neuropathy may also contribute.

New coding guidance
Home health coders are well aware of the link between diabetes and narrowing of the arteries, and are used to combing medical records for specific documentation by the physician of the cause and effect.
New coding guidance, however, has impacted the need for specific links such as “due to” in notes from the physician regarding the diagnosis of a diabetes-related condition which results in certain circulatory complications.
The guidance change has left many home health coders feeling wary and uncertain as they tread this new ground. Online coding forums are filled with questions about the need to link arterial flow conditions such as Peripheral Vascular Disease with a diagnosis of Diabetes Mellitus.
Based on new AHA Coding Clinic guidance for the linkage between DM and certain conditions, some arterial conditions causing blood flow restrictions in patients who also have a diagnosis of DM may now be assumed to be linked to the diabetes —  even without specific documentation from the physician.
       The ICD-10 classification assumes the link in ICD-10 coding manuals wherever it lists subterm conditions indented beneath the word “with” alongside a diagnosis such as diabetes mellitus.
Note that two other requirements must also be met:
1. There must be documentation by the physician of both the diagnosis AND the condition
2. There must be no other reason provided for the condition

For example, the physician may not have directly attributed a patient’s peripheral angiopathy without gangrene to diabetes, but if there is a diagnosis of Type 2 DM and documentation of the patient’s peripheral angiopathy, you would select the code E11.51 for Type 2 DM with diabetic peripheral angiopathy without gangrene.

Coding arterial ulcers
As with everything coded in ICD-10, great specificity is required when coding arterial ulcers and the diagnoses and conditions associated with them.
Coders will need to use additional codes to identify specific ulcers. Laterality MUST be documented. Even the severity of the ulcer must be noted.
Avoid using unspecified codes if at all possible. Code to the highest level of specificity. The new coding guidance referenced above actually makes this level of specificity easier to achieve in many instances because the ICD-10 classification set assumes some of the burden of properly linking diagnoses and conditions, and allows the selection of a code establishing the underlying condition as well as its manifestation.
It is critically important for coders to remain diligent in carefully reading and following all guidelines as they code arterial ulcers and associated conditions.
As always, proceed very carefully with attention to the directions provided in the classification set itself. Pay very close attention to details such as Excludes 1 and Excludes 2 notes, and requirements to use additional codes. Make sure to document underlying diseases as appropriate.