Gastroenterology Coding Alert

Tip: Watch for peritoneal involvement as in ICD-9 codes.

Abdominal pain is one of the most common symptoms that you will encounter in your gastroenterologist's practice. One common emergency reason for abdominal pain is acute appendicitis, so understanding how to report acute appendicitis will come in handy when ICD-10 go into effect.

When your gastroenterologist makes a diagnosis of acute appendicitis, you will probably see the following details in the documentation:

Symptoms such as abdominal pain (R10.31, Right lower quadrant pain), that is often in the right lower quadrant although this may vary in some patients, and anorexia (R63.0, Anorexia). Some of the other symptoms that your gastroenterologist might note in the documentation might include nausea, vomiting (R11.2, Nausea and vomiting), diarrhea (R19.7, Diarrhea, unspecified) and constipation (R15.0, Incomplete defecation).

Based on the signs and symptoms, if your gastroenterologist suspects a diagnosis of acute appendicitis, he might order many tests to confirm the diagnosis. Some of the tests that you might see in the documentation might include a CBC count, C - reactive protein, and urinalysis.

Apart from this, your gastroenterologist might also perform x-ray of the abdominal area, ultrasound or a CT scan of the appendix following a Gastrografin enema. Ultrasound tests are performed to confirm diagnosis of appendicitis following observations found in the CT scan.

Reporting Acute Appendicitis in ICD-9

When you are reporting acute appendicitis using ICD-9 codes, you need to delve more into the documentation to check for localized or generalized peritonitis. Based on the presence or absence of peritonitis, you currently have three choices for reporting acute appendicitis using the ICD-9 codes:

• 540.0 -- Acute appendicitis with generalized peritonitis
• 540.1 -- Acute appendicitis with peritoneal abscess
• 540.9 -- Acute appendicitis without peritonitis

Observe Peritonitis Details for ICD-10 Selection

With ICD-10, you'll report a diagnosis of acute appendicitis on the same basis as you are currently doing using ICD 9 codes by checking for the presence or absence of peritonitis.

Under ICD-10, code, 540.0 crosswalks to K35.2 (Acute appendicitis with generalized peritonitis) with no descriptor changes. The other two codes -- 540.1 and 540.9 -- crosswalk to K35.3 (Acute appendicitis with localized peritonitis) and K35.8 (Other and unspecified appendicitis) respectively. The descriptors to the codes in ICD-10 have changes that bring in more specificity depending on the involvement of the peritoneum (localized or generalized). Note that K35.3 is also used to report acute appendicitis with peritoneal abscess, as is done at present using 540.1 in ICD-9.

K35.8 further expands to two different codes, K35.80 (Unspecified acute appendicitis) that includes acute appendicitis without any peritonitis and acute appendicitis that is not otherwise specified (NOS) and K35.89 (Other acute appendicitis).

Example: An 18-year-old male patient reports to your gastroenterologist with complaints of severe epigastric pain that has been present for the past forty-eight hours with increasing intensity. He also complains of nausea and vomiting.

Your gastroenterologist conducts a comprehensive evaluation of the patient during which he observes tenderness to percussion and Dunphy's sign (increased pain with coughing) positive. He suspects acute appendicitis and orders blood tests (CBC), test for C-reactive protein and urinalysis. He also asks for a CT scan. Based on the findings at examination and tests, your gastroenterologist arrives at a diagnosis of appendicitis with localized peritonitis. You report the diagnosis with K35.3.