Diabetic complications—Part 1

Learn to properly document common acute complications of diabetes.


The metabolic consequences of diabetes mellitus are directly responsible for many well-recognized acute and chronic complications in several organ systems, such as retinopathy, neuropathy, and nephropathy. This month's column will define these complications, explain diagnostic criteria, and identify the complex coding rules and documentation challenges related to diabetes and its acute complications.

Image by Getty Images
Image by Getty Images

Diabetes is diagnosed by the finding of any one of the following: 1) HbA1c greater than or equal to 6.5%; 2) fasting (>8 hours) blood glucose level greater than 125 mg/dL (6.9 mmol/L); 3) two-hour blood glucose level greater than 200 mg/dL (11.1 mmol/L) during oral glucose tolerance test or 4) random blood glucose level above 200 mg/dL (11.1 mmol/L) associated with symptoms.

ICD-10-CM recognizes six types of diabetes that are consistent with clinical classifications: type 1, type 2, diabetes due to an underlying disease process (e.g., chronic pancreatitis), diabetes due to medications or toxins like steroids or dioxins, diabetes associated with pregnancy, and other specified type. “Other specified type” includes postprocedural causes and type 1.5, the term that has been coined for diabetic patients who manifest characteristics of both type 1 (insulin deficiency) and type 2 (peripheral insulin resistance).

Each of these six types is assigned to its own three-digit code category (Table 1), and complications (which tend to occur with diabetes in all the categories) are identified by additional appended digits (see Table 2 for some examples).

The revenue and quality reporting impact of precise documentation of diabetes and its complications can be substantial. In some instances, the identification of complications affects the diagnosis-related group (DRG) assignment whether as principal diagnoses, complications/comorbidities (CCs), or major complications/comorbidities (MCCs).

Furthermore, identification and coding of diabetic complications affect risk adjustment under the hierarchical condition categories (HCCs) that influence most Medicare quality parameters and determine reimbursement for accountable care organizations and certain other risk-sharing programs. Diabetic complications need to be specifically identified and coded because the HCCs for these codes have a much higher value than the HCC for uncomplicated diabetes.

ICD-10-CM recognizes four acute diabetic complications: hypoglycemia, hyperglycemia, hyperglycemic hyperosmolar state (HHS), and diabetic ketoacidosis (DKA). The five chronic complications will be addressed in next month's column. There is also a code for “unspecified” complication, which is hardly ever used because any complication should always be specified in the medical record.

The acute complications are rather straightforward so long as clinicians are familiar with the authoritative definitions. Hypoglycemia is simply defined as a blood glucose level below 70 mg/dL (3.9 mmol/L), with codes for the presence or absence of concomitant coma (e.g., in type 2, code E11.649 without coma and E11.641 with coma), even if transient. Whenever a diabetic patient is hypoglycemic during an admission, it should be documented for correct coding.

Hyperglycemia (code E11.65) is defined as a blood glucose level above 140 mg/dL (7.8 mmol/L). If hyperglycemia is associated with coma, it should be clearly documented to ensure correct coding. Many patients will experience hyperglycemia during hospitalization, and it should be documented on days when it occurs. For the days when blood glucose does not exceed this level, diabetic hyperglycemia should not be listed as a diagnosis, so be careful about copying and pasting without editing in the medical record.

Whether the cause is hypoglycemia or hyperglycemia, the Glasgow Coma Scale score should be recorded for all cases with coma or with lesser degrees of altered consciousness.

Under ICD-9-CM, the distinction between controlled and uncontrolled diabetes was important. With ICD-10-CM, these terms are no longer used to describe diabetes. The term “uncontrolled” must be clarified by clinicians as either hyperglycemia or hypoglycemia. Clinically, by uncontrolled, we almost always mean hyperglycemia (code E11.65 in type 2). However, the terms “out of control” and “poorly controlled” are assigned as hyperglycemia without further clarification. The word “controlled” is not referenced at all by ICD-10-CM. Codes for nondiabetic hyperglycemia (R73.9) and hypoglycemia (E16.2) also exist but are never used with diabetes.

Clinicians need a clear understanding of HHS and DKA to avoid overdiagnosis and improper coding. HHS (codes E11.00 without coma and E11.01 with coma for type 2) is defined by the presence of both a blood glucose level above 250 mg/dL (13.9 mmol/L) and serum osmolality greater than 320 mmol/L.

The diagnosis of DKA (for type 2, codes E11.10 without coma and E11.11 with coma) requires all of the following: 1) a blood glucose level above 250 mg/dL (13.9 mmol/L); 2) acidosis with a pH below 7.30; 3) a bicarbonate level below 18 mEq/L; and 4) markedly elevated serum ketones. Therefore, DKA cannot be properly diagnosed without an arterial blood gas and serum ketone measurement.

Urinary ketones are not used to establish ketoacidosis. Do not use the term “ketosis” in diabetic patients based on urinary ketones alone, as this will cause improper assignment of a DKA code. A diagnosis of ketosis or ketoacidosis in diabetic patients always requires elevated serum ketone levels.

Ask Dr. Pinson

Q: Our quality department is using Sepsis-2/systemic inflammatory response syndrome (SIRS) criteria for Medicare quality reporting. Our medical staff is using Sepsis-3 for diagnosis and documentation purposes. This is causing quality deficiencies because our medical staff does not base their severe sepsis management on Sepsis-2/SIRS. When Sepsis-2/SIRS criteria are used for diagnosis, we are receiving payer and audit contractor denials because those entities use Sepsis-3 to validate the diagnosis of sepsis. What should we do about this perplexing problem?

A: Thanks for this interesting and important question. It's a challenging dilemma for every hospital.

First, for the sepsis quality measure (SEP-1) in Medicare's inpatient quality reporting (IQR) program, hospital quality departments are required to use the National Quality Forum's (NQF) severe sepsis management bundle (NQF #0500). This is derived from the Sepsis-2 definition of sepsis as SIRS due to infection (which requires that patients meet two or more criteria regarding white blood cell count, temperature, respiration, and pulse criteria and only certain particular organ dysfunction criteria).

Unfortunately, many payers have changed from the Sepsis-2/SIRS criteria to Sepsis-3 for clinical validation of a sepsis diagnosis. If the diagnosis of sepsis on a claim is substantiated in the record only by Sepsis-2/SIRS criteria, the diagnosis of sepsis may be removed from the claim.

To deal with this perplexing dilemma, the medical staff may follow both Sepsis-3 and Sepsis-2 criteria to screen patients for severe sepsis and to initiate the NQF severe sepsis bundle. If the record only substantiates severe sepsis based on SIRS criteria, so be it and let the “chips fall where they may” with the payers.

One more word of advice when a claim for sepsis is denied because Sepsis-2/SIRS was the basis for the diagnosis: Review the record carefully for Sepsis-3 criteria that may have otherwise been overlooked and could be used in an appeal.

Q: We have been receiving recovery denials for specific types of encephalopathy, including metabolic encephalopathy, “due to” urinary tract infection (UTI), based on page 22 and page 24 of Coding Clinic 2nd Quarter 2018. Can you suggest any response for appeals?

A: Thanks for this interesting question. Page 22 has to do with a diagnosis of encephalopathy, not otherwise specified by type, caused by UTI. It states that code G93.49 (other encephalopathy) should be assigned, and that the principal diagnosis depends on the primary reason for admission. Encephalopathy is almost always the primary reason for admission when caused by UTI that is otherwise uncomplicated.

An uncomplicated UTI can almost always be treated as an outpatient or observation; inpatient admission is not ordinarily necessary. The reason for admission is typically the complication, like encephalopathy, that requires inpatient admission and evaluation. Nothing much needs to be done about the UTI in such circumstances except culture and antibiotics, which might otherwise be given orally. Encephalopathy, on the other hand, requires thorough evaluation and management.

Page 24 states that when encephalopathy is linked to a specific condition, such as stroke or urinary tract infection, but a specific encephalopathy (e.g., metabolic, toxic, hypertensive, etc.) is not documented, it is appropriate to use the code describing “other encephalopathy” (G93.49, a comorbidity/complication [CC]). However, encephalopathy due to UTI is “metabolic,” so it should be documented as such and code G93.41 (a major complication/comorbidity [MCC]) would be assigned, not G93.49

I hope this information will assist with precise documentation of encephalopathy, which should include clarification of whether it is metabolic, toxic, toxic-metabolic, septic, or another specific type.