Wear Your Detective Hat for Postpancreatectomy Diabetes Mellitus
Following guidelines and asking questions are key to solving the T3cDM coding mystery.
One guideline in ICD-10-CM consistently overlooked is I.C.4.a.6.b.i., which is specific to secondary diabetes mellitus due to a pancreatectomy.
I.C.4.a.6.b.i. Secondary diabetes mellitus due to a pancreatectomy
For postpancreatectomy diabetes mellitus (lack of insulin due to the surgical removal of all or part of the pancreas), assign code E89.1, Postprocedural hypoinsulinemia. Assign a code from category E13 and a code from subcategory Z90.41-, Acquired absence of pancreas, as additional codes.
This guideline prompts a number of questions that must be answered before a thorough understanding can be attained.
Ask Questions, Get Answers
Why is this type of diabetes assigned to category E13 rather than category E08?
E08 Diabetes mellitus due to underlying condition
E13 Other specified diabetes mellitus
You may argue absence of some or the entire pancreas would be an underlying condition — and that is correct. But if you look at how the categories of diabetes are divided in ICD-10-CM, you find category E13 pulls several underlying conditions out from category E08. Specifically, if the underlying condition is genetic (affecting beta-cell function or insulin action), surgical, or a condition not included in another category, it is coded to category E13.
This understanding prompts two more questions:
Why is postpancreatectomy diabetes mellitus included in category E13?
What specifically makes this type of diabetes different from the other categories?
According to “Managing Diabetes and Hyperglycemia in the Hospital Setting, A Clinician’s Guide” (B. Draznin), postpancreatectomy diabetes mellitus is classified, along with a few other conditions, into its own type of diabetes mellitus, commonly referred to as pancreatogenic or type 3c diabetes mellitus (T3cDM). In this type of diabetes mellitus, the clinical indicators include both a lack of adequate insulin secretion and concomitant loss of glucagon secretion by alpha-cells. In layman’s terms, the body is neither making enough insulin, nor is it making enough of the hormone needed to increase the glucose levels in the blood. These symptoms can make it difficult for the provider to determine if the patient has type 2 DM (T2DM) or T3cDM without further assessment of autoantibodies or ongoing insulin resistance. This is particularly true in patients with pre-existing T2DM prior to surgery.
This information leads to several more questions.
Open the Flood Gate of Clinical Questions
Is there a common pathology that leads to T3cDM?
What condition(s) may lead to the need for or are treated with a pancreatectomy?
What are the most common types of pancreatectomies?
How does the type of pancreatectomy affect the diagnosis codes assigned?
T3cDM is found, primarily, in patients with one of three conditions: chronic pancreatitis, cystic fibrosis, or pancreatic resection (partial or complete). Although treatment for specific cases (usually severe) of chronic pancreatitis or cystic fibrosis may include pancreatic resection, pancreatic resection also may be performed to treat neoplasms (primarily malignant) and severe trauma to the pancreas and surrounding structures.
In CPT®, there are eight different options for pancreatectomy (not including those performed for transplantation); however, those eight options break into just three categories:
48140-48146 – Distal pancreatectomy
48150-48154 – Whipple-type pancreatectomy (includes duodenectomy)
48155 – Total pancreatectomy
From an ICD-10-CM perspective, there are two options for indicating acquired (versus congenital) absence of the pancreas:
Z90.410 Acquired total absence of pancreas
Z90.411 Acquired partial absence of pancreas
Regardless of the type of pancreatectomy, most patients who develop T3cDM following pancreatic resection begin experiencing symptoms within the first five years after surgery.
An understanding of why postpancreatectomy diabetes mellitus is assigned to category E13 enables you to ask a few questions specific to ICD-10-CM guideline I.C.4.a.6.b.i.:
Why is E89.1 Postprocedural hypoinsulinemia first?
What is postprocedural hypoinsulinemia?
Are patients with T3cDM always insulin dependent?
If a patient has postpancreatectomy diabetes mellitus, the patient has postprocedural hypoinsulinemia. Postpancreatectomy diabetes mellitus is caused by a lack of insulin production due to the absence of some of or all the pancreas. Postprocedural hypoinsulinemia represents an abnormally low concentration of insulin in the blood. Insulin dependence in T3cDM patients depends on factors, including how much of the pancreas was removed. In the case of a total pancreatectomy, the patient will be insulin dependent from that point forward (because they no longer have a pancreas to produce insulin); in which case, Z79.4 Long term (current) use of insulin also must be reported.
Leave No Stone Unturned
How many pancreatectomies are performed each year?
According to “Managing Diabetes and Hyperglycemia in the Hospital Setting, A Clinician’s Guide,” between 1998 and 2006, approximately 102,417 pancreatectomies were performed. Although that number has increased in recent years, it averages out to just over 1,000 pancreatectomies per month. Of the 102,417 performed in that time, half were performed for removal of malignant tumors and a third were performed for non-malignant conditions (including chronic pancreatitis and cystic fibrosis).
What elements of documentation may help identify when to ask questions?
From a documentation perspective, if the record indicates a pancreatectomy (partial or total, including Whipple procedures) has been performed, or that the patient has cystic fibrosis or chronic pancreatitis, do not assign codes from categories E08-E11 without first asking questions. These conditions may be more accurately reported with a diagnosis code from category E13 — even if the patient had a previous diabetes diagnosis.
Correct Coding Matters
Does it really matter which diabetes code I use or if I remember the E89.1?
Yes, it does. Accuracy depends on following the established rules and guidelines, and fully understanding the clinical conditions. Code assignment drives national statistics and wrong code assignment may affect payment. For example:
|Physician||Payer policies may require E89.1 to be the first-listed diagnosis code for medical necessity.|
|Inpatient||E89.1 leads to different diagnosis-related group options and relative weights than the E13 codes; some E13 codes (with complication) may have a higher risk adjustment factor than others.|
|Risk Adjustment||E89.1 does not risk-adjust in hierarchical condition categories, but E13 codes do.|
Documentation drives the revenue cycle of healthcare, but many providers may not know all the intricacies required by the code
sets and coding guidelines. It is our responsibility as coders, auditors, reviewers, etc., to see the elements of the clinical picture that affect code selection, as well as those needing further elaboration by the provider. When these scenarios arise, discussion with the provider ensures the record accurately reflects the patient’s conditions and that those conditions are correctly reflected in the codes reported.