Home Health Coding and OASIS Expert

Get the background on these ICD-10 coding differences.

Before you can care for — or code for — a patient’s ulcer, you need to have a thorough understanding of the type of wound you’re dealing with. Give yourself a refresher on the differences between types of ulcers to boost your precision when documenting these wounds.

Look to Etiology First

Wound care coding and OASIS documentation have always been challenging. Before you can document and code for an ulcer, you need to know what type of wound you’re dealing with, said Judy Adams, RN, BSN, HCS-D, HCS-O, AHIMA Approved ICD-10-CM Trainer with Adams Home Care Consulting in Asheville, N.C.

Coding guideline: Even as you move to the ICD-10 code set, the old rule remains the same: the physician or other person legally authorized to determine diagnoses must determine the type of wound, Adams said during the recent Eli-sponsored audioconference “Unravel Wound Care Coding in ICD-10.”

Do this: Clinicians, however, can determine the stage or severity of the wound.

Understanding the origin of an ulcer is imperative, Adams said. Knowing what caused your patient’s ulcer will not only allow you to code for it correctly, it will also help you to choose the appropriate interventions to treat it correctly.

Fortunately, each of the most common types of ulcers seen in home care provide clues to their origin, Adams said. As a clinician, you ferret out the clinical characteristics to identify the type of ulcer and then document that you verified the diagnosis with the physician. Consider the following characteristics of different types of ulcers as you care for patients with these types of wounds.

Pressure Ulcers develop when pressure on the skin prevents an adequate blood supply from delivering needed oxygen to the tissue and the skin breaks down, Adams said. These ulcers occur over bony prominences or areas of little fat or muscle and may be caused by pressure, shear, friction, or an orthopedic or prosthetic device, such as a cast or prosthesis. Pressure ulcers present as redness, blisters or open wounds and can be staged by depth into four levels of severity.

Coding guideline: To code for the ulcer stage (based on Wound Ostomy and Continence Nurses Society (WOCN) guidelines), look to the clinical documentation in the medical record.

New: In ICD-10-CM, you’ll find combination codes for pressure ulcers that include the location and stage within the individual code. Look to category L89.- (Pressure ulcer) for more detailed codes such as L89.323 (Pressure ulcer or of left buttock; stage 3).

Remember to code for all pressure ulcers, including stage I and closed Stage III and IV ulcers because closed Stage III and IV pressure ulcers are never fully “healed,” Adams said.

Improved: ICD-10 diagnosis codes include the full definition of each stage of pressure ulcer along with the code in the Tabular List. That means you’ll no longer need to cross-reference the National Pressure Ulcer Advisory Panel (NPUAP) or WOCN guidelines that define each stage in order to select the correct code. For example, at L89.323, you’ll find the following details: “Pressure ulcer with full thickness skin loss involving damage or necrosis of subcutaneous tissue, left buttock.”

Documentation tip: While the physician must document or verify that the ulcer is a pressure ulcer, the clinician can determine the correct stage based on the WOCN guidelines, Adams said. Once you’ve completed the assessment, be sure to document the stage and location of each pressure ulcer in the medical record. And update this information at each assessment time point.

You can report pressure ulcers as either unstageable or of unspecified stage, but it’s important to understand the difference between these two designations.

An unstageable pressure ulcer is defined as full thickness skin or tissue loss in which the base of the ulcer is covered by slough and/or eschar in the wound bed which renders the wound unstageable, Adams explained. “Until enough slough or eschar is removed to expose the base of the wound, the true depth (and therefore the stage) cannot be determined.”

If you code for a pressure ulcer as unspecified, you’re saying that the documentation doesn’t include the details you need to describe the stage of the pressure ulcer. Unspecified codes should be used sparingly. Make the effort to gather the details you need in order to code more accurately for your patient’s wound.

Coding tip: There’s no need to group all your patient’s pressure ulcers together in the list of diagnoses, Adams said. As with all sequencing, you should base the order of codes on the seriousness of the condition to the patient’s plan of care.

Stasis Ulcers are caused by problems in the veins of the lower leg. These wounds occur when leaky valves, obstructions, or regurgitation disturb the flow of blood from the lower extremities back to the heart. The blood collects in the lower leg, damaging the tissues and causing wounds.

When coding for chronic ulcers of the lower limb, except pressure ulcers, you’ll need to sequence a code for the underlying condition (if appropriate) first, followed by a code from the L97.- (Non-pressure chronic ulcer of lower limb, not classified elsewhere) category to identify the location and severity of any associated ulcer.

This applies to ulcers of the lower limb that may be referred to as: atrophic, chronic, neurogenic, perforating, pyogenic, trophic, or tropical.

Coding tip: When your patient has a stasis ulcer with varicose veins, the Alphabetic Index instructs you to look under “Varix, leg, with ulcer.” If the patient has a stasis ulcer with no mention of varicose veins, you’ll report it with I87.2 (Venous insufficiency [chronic] [peripheral]) and add an additional L97.- code to specify the site and severity of the ulcer.

Venous ulcers may also be associated with postthrombotic syndrome (I87.0-) or Chronic venous hypertension (idiopathic) I87.3-, Adams said.

Ulcers are more likely to develop when the stasis gets to the level of chronic venous hypertension, so query the physician if you suspect this might be the case with your patient, says Lisa Selman-Holman, JD, BSN, RN, COS-C, HCS-D, HCS-O, AHIMA Approved ICD-10-CM Trainer/Ambassador of Selman-Holman & Associates, LLC, CoDR — Coding Done Right and Code Pro University in Denton, Texas.

Unfortunately physicians do not usually provide this level of detail in their documentation, Selman-Holman says. “So, chronic venous insufficiency is what we will usually code as the cause of a stasis ulcer.”

Neuropathic Ulcers typically result from diabetic peripheral neuropathy. These ulcers are usually found on the bottom of the foot and tips of the toes. They are painless, surrounded by callus, and associated with good foot pulses, Adams said.

You may also encounter patients with non-pressure chronic ulcers of the skin, not elsewhere classified, Adams said. These include chronic ulcer of the skin, not otherwise specified (NOS), tropical ulcers NOS, and ulcer of the skin NOS.

Coding example: For a patient with a non-pressure ulcer of the buttock limited to skin breakdown, you would report L98.411 (Non-pressure ulcer of skin of other sites with fat layer exposed).

Note: Now that you’ve given yourself a refresher on ulcer coding in ICD-10, challenge your skills with the coding quiz below. Order a CD or transcript of Adams’ audioconference “Unravel Wound Care Coding in ICD-10” here: www.audioeducator.com/icd-10/wound-care-coding-in-icd-10-cm-07-02-2015.html.