General Surgery Coding Alert

Coding the 6^th character is a must.

When your general surgeon treats a patient with a pressure ulcer, you will encounter numerous options as you strive to refine the diagnosis and procedure coding.

We’ll look at one case together, reviewing the step-by-step process used to choose the most precise codes that represent both your surgeon’s work and the patient’s medical condition. Then, you’ll have a chance to review a second case on your own.

Case 1: A 42-year-old patient presents with a pressure ulcer on their left heel measuring 24 sq cm. The surgeon observes loss of tissue extending to the bone, accompanied by a necrotic wound and emerging gangrene. The surgeon employs forceps, scissors, and a scalpel to excise the dead or infected tissue, thereby cleaning and debriding the pressure wound. The surgeon dresses and bandages the wound and instructs the patient to stay off the foot, keeping the ulcer clean and dressed, and the patient will follow up in one week.

Zero In on Procedure Code

To accurately report the surgeon’s work in this case, turn to the wound debridement codes 11042-+11047 (Debridement, subcutaneous tissue (includes epidermis and dermis, if performed…).

Remember: These codes are based on the depth of the ulcer, not the anatomic site.

In this case, you’ll choose 11044 (Debridement, bone (includes epidermis, dermis, subcutaneous tissue, muscle and/or fascia, if performed); first 20 sq cm or less) for the initial 20 sq cm and +11047 (… each additional 20 sq cm, or part thereof (List separately in addition to code for primary procedure)) for the additional 4 sq cm the surgeon documents.

Because the surgeon documents tissue loss down to the bone, you shouldn’t select one of the other debridement codes for wounds no deeper than subcutaneous tissue (11042/+11045, Debridement, subcutaneous tissue (includes epidermis and dermis, if performed) …) or wounds no deeper than the fascia (11043/+11046, Debridement, muscle and/or fascia (includes epidermis, dermis, and subcutaneous tissue, if performed) …).

Do the math: Since these codes are determined by depth rather than anatomical location, you should only use a single code (plus an associated add-on code, if appropriate) per depth per day. That’s true even if the surgeon debrides multiple wounds of the same depth at different sites. In fact, some practices are seeing denials due to overbilling of the codes at the same depth due to this error in coding.

Follow Signs for Accurate Diagnosis

Prior to delving into the L89.- (Pressure ulcer) codes, it’s crucial to heed the “Code first” note that is associated with the group. There, you’ll find the instructions to sequence I96 (Gangrene, not elsewhere classified) before documenting the specified pressure ulcer, if applicable.

Anatomic site: Given that pressure ulcer codes are initially categorized by location, identifying the first four characters of the diagnosis code is fairly easy. The provider’s documentation specifies that the pressure ulcer is located on the patient’s heel, so in this case, you’ll refer to the L89.6- (Pressure ulcer of heel) codes to begin considering your code options.

Warning: If your provider has documented an anatomic location on the patient’s foot that is neither the heel nor the ankle, you may have to look to ICD-10-CM code L89.89- (Pressure ulcer of other site) as your diagnosis. This means that the provider has indicated where the ulcer is, but there is not a precise code under L89.- that specifies where exactly on the foot or ankle the site is documented.

Don’t confuse “other” with L89.9- (Pressure ulcer of unspecified site), which would mean that the provider has not documented where the ulcer is at all. In essence, the difference lies in the specificity of the location of the pressure ulcer. Code L89.89 is used when the location is known but not listed in the L89.- category, while L89.9- is used when the location is not known at all.

Laterality: Next, you’ll add a 5^th character to specify laterality — in this case, the “2” in L89.62 (Pressure ulcer of left heel) indicates the left heel.

Severity: You will need to determine the 6^th character of the code to document the severity of the ulcer. Your character choices are:

• 0: Unstageable
• 1: Stage 1 (Pressure pre-ulcer skin changes limited to persistent focal edema)
• 2: Stage 2 (Pressure ulcer with abrasion, blister, partial thickness skin loss involving epidermis and/or dermis)
• 3: Stage 3 (Pressure ulcer with full-thickness skin loss involving damage or necrosis of subcutaneous tissue)
• 4: Stage 4 (Pressure ulcer with necrosis of soft tissues through to underlying muscle, tendon, or bone)
• 6: Deep tissue damage
• 9: Unspecified stage

In the above case, the decision is simplified due to thorough documentation by the provider. Given that the tissue loss extends to the bone and the wound has turned necrotic, you are looking at a stage 4 ulcer. That means you should apply a 6^th character “4,” giving you L89.624 (Pressure ulcer of left heel, stage 4).

Caution: When it comes to coding the severity of the ulcer, the staging classifications “unspecified” and “unstageable” can be daunting. If you follow ICD-10-CM Official Guidelines, Section I.C.12.a, you’ll find that unstageable means that the depth, or stage, of the wound cannot be determined because slough and/or eschar are covering the wound bed, you should come to the correct conclusion in no time. Keep in mind, however, that in rare instances, your provider may not initially remove this tissue to determine the stage because leaving the tissue in place may enable the wound to heal. However, having to code a pressure ulcer as “unstageable” is a rare occurrence.

Try This Case on Your Own

Case 2: With very few notes from the practitioner to go on, you need to find a suitable ICD-10-CM code that would validate the medical necessity for a skin graft operation on a severe pressure ulcer situated on the left ankle. The provider’s documentation during the grafting process does not encompass any recorded staging of the ulcer. When inputting a diagnosis code to justify this operation, should you classify the pressure ulcer as unspecified based on the initial condition of the wound; or should you categorize it as unstageable owing to its condition post-procedure?

Answer: According to the ICD-10-CM Official Guidelines, sections I.C.12.a.1-3, unstageable wounds occur when you can’t assess and determine the depth of a wound, especially when the wound has produced eschar or after the wound has been covered by a skin graft. An unspecified wound occurs when the stage has not been documented whether the depth can be determined or not.

In a case where a provider has performed a skin graft, the depth of the decubitus ulcer can no longer be assessed after the procedure, even by the surgeon. You would classify the decubitus ulcer by its current stage after the skin graft, which is unstageable, L89.520 (Pressure ulcer of left ankle, unstageable).

However, to validate the CPT^® procedure code, the diagnosis code should specify the stage of the pressure ulcer prior to the skin graft, thus underscoring the necessity for more precise coding. If feasible, confirm the stage directly with the physician, who should provide additional documentation for clarification, or refer to prior notes if available. If you’re unable to do that, you’ll have to code L89.529 (Pressure ulcer of left ankle, unspecified stage).

Additional information: For more details about the National Pressure Ulcer Staging System, go to https://www.ncbi.nlm.nih.gov/books/NBK2650/pdf/Bookshelf_NBK2650.pdf.

Lindsey Bush, BA, MA, CPC, Development Editor, AAPC