Correctly documenting and coding altered mental status and encephalopathy

by James S. Kennedy, MD, CCS, CDIP

Last month, I wrote about the role of coding and CDI compliance in ensuring the clinical validity of submitted ICD-10-CM/PCS codes, which impact payment, outcomes measurement (e.g., complications, mortality, and readmissions), and patient safety.

Emphasizing that ICD-10 code assignment can no longer rely solely upon the words documented by a treating provider, a team effort involving compliance, coders, CDI, and physicians defining clinical terminology and managing the application of code conventions, guidelines, and official advice is crucial.

While a good lawyer knows the law, a better lawyer knows the law, the judge, and the jury. We in coding compliance must know not only the code assignment process, but also the accountability agents and attorneys who delight in finding what they perceive to be our mistakes.

In our defense, when we can state our case using the most up-to-date clinical definitions for the circumstances described by a treating provider and rigorously apply coding and CDI principles, we are more likely to prevail when publically accused of upcoding, abuse, or fraud.

On July 27, I was interviewed by the director of ­ACDIS, Brian Murphy, regarding the documentation and coding of encephalopathy, which has highlighted the tremendous confusion in the compliant definition, documentation, and coding of altered mental status and its underlying causes. This interview and its accompanying slides are available at http://www.acdis.org/acdis-radio/encephalopathy.

To discuss this topic, let’s review a little history first. The documentation and coding of encephalopathy wasn’t much of an issue until around 2007, when CMS designated the various encephalopathies (e.g., metabolic, toxic) as MCCs when they weren’t even CCs in the older CMS-DRG system.

Unlike unspecified heart failure?which is not a CC or MCC unless the physician states that it is systolic (HFrEF) or diastolic (HFpEF)?CMS allows unspecified or acute encephalopathy (ICD-10-CM code G93.40) to be an MCC while some of its descriptors (e.g., anoxic encephalopathy) are just a CC or nothing at all (e.g., G94, encephalopathy in diseases classified elsewhere).

When challenged as to why encephalopathy with (e.g., toxic, hepatic, metabolic, or NEC) or without an adjective should remain a MCC, CMS stated in its fiscal year (FY) 2012 IPPS rule that "its clinical advisers recommended that these encephalopathy codes remain at an MCC level because these patients with encephalopathy typically utilize significant resources and are at a higher severity level." Readers can view this quote in the Federal Register on pp. 51544 and 51545 at http://tinyurl.com/jv69k8m.

Consequently, several hospitals and CDI consultants continue to advocate documentation and coding of the term "encephalopathy" alone in the presence of any altered mental status in order to obtain a MCC in MS-DRGs or a severity of illness of 3 in APR-DRGs. This is a practice that I believe is sure to be challenged, and one that requires thoughtful inquiry to ensure the validity of this or an alternative strategy.

Strategies for accuracy

Let’s now outline how to structure a diagnosis or condition for the purpose of ensuring completeness and precision in its ICD-10-CM coding. Every condition has five components that must be documented and linked to each other to fully describe that condition for coding purposes. Using the mnemonic MUSIC, and applied to an altered mental status, these are:

• Manifestations?These could be delirium, psychosis, dementia, amnestic disorder, stupor, coma, unconsciousness, chronic vegetative state, and others, not just altered mental status or altered level of consciousness. Many of these are Chapter 18 symptoms, which cannot be a principal diagnosis if attributed to their underlying causes.
  • Note: Unresponsive doesn’t have a code; thus, an alternative term must be used.
  • Note: ICD-10-CM has code first requirements for the underlying cause of dementia (F01, F02), amnestic disorders (F04), delirium (F05), or other mental or personality disorders (F06, F07) due to a known physiological disorder, which means that if they were not documented or linked to the specified alteration of mental status or consciousness, they should be queried for. See the next section.
• Underlying causes?These may include various structural brain diseases (e.g., strokes, cerebral neoplasms, cerebral edema, traumatic brain injury), neurodegenerative disorders (e.g., Alzheimer’s, Lewy body dementia, normal pressure hydrocephalus), or the various encephalopathies (e.g., toxic, metabolic, anoxic).
• Severity or specificity?This includes whether any brain disease due to injury or medications is in the active treatment phase (initial encounter), healing phase (subsequent encounter), or has long-standing sequelae. If the doctor only documents "encephalopathy," we should query him or her as to its specific nature or underlying cause.
  • Note: The Glasgow Coma Scale measures severity; ICD-10-CM will add the National Institutes of Health Stroke Scale starting October 1, 2016. Note that both of these may be coded from non-provider documentation according to the 2017 ICD-10-CM Official Guidelines released in ­August 2016; thus, please encourage the nursing staff to capture these whenever possible.
  • Note: We may see codes for the severity of hepatic encephalopathy using the West-Haven classification (0, 1, 2, 3, or 4) in FY 2018; thus, consider discussing this with your gastroenterologists or hepatologists.
• Instigating or precipitating cause?This is another condition that provoked the underlying cause or made it worse, such as a drug overdose causing a toxic encephalopathy, a cerebral embolus from atrial fibrillation causing a stroke, or a change in circumstances inciting behavioral changes with neurodegenerative disorders. Elder or child abuse should always be considered as well.
• Consequences?These include seizures that may be the direct effect of a metabolic encephalopathy due to hyponatremia, a fracture that occurred during a drug-induced delirium or psychosis, or malnutrition due to poor oral intake in a patient with end-stage Alzheimer’s disease.

The definitions of the various altered mental states or levels of consciousness can be found in credible psychiatry (e.g., DSM-V) or neurological literature (e.g., Adams and Victor’s Principles of Neurology); thus, when the term "altered mental status" alone is documented, the physician should be queried for the exact nature of the altered mental state (e.g., delirium, amnestic syndrome, dementia). Please ask your coding or CDI physician champion for additional information on these definitions.

Focusing on encephalopathy

While there are many causes of altered mental status, let’s focus on encephalopathy.

The Greek etymology of the word "encephalopathy" means "disease of the brain," much like how the word "myopathy" means "disease of the muscle," "nephropathy" means "disease of the kidney," and "neuropathy" means "disease of the nerve." As such, one could construe any disease of the brain to be an encephalopathy, such as strokes, brain tumors, and the like. In fact, Dorland’s medical dictionary, available in 3M’s encoder, defines encephalopathy as "any degenerative disease of the brain." These definitions, in my opinion, are too broad.

I prefer the definition in Adams and Victor’s Principles of Neurology, 10th Edition, that defines encephalopathy as a global brain dysfunction that has an underlying cause distinct from any other named brain disease (e.g., Alzheimer’s). It could be a general medical condition (e.g., metabolic encephalopathy), a poisoning (e.g., toxic encephalopathy), chronic liver failure (e.g., hepatic encephalopathy), diffuse anoxia, or the like that results in the diffuse brain dysfunction. These, of course, would have to be defined, differentiated, and documented by the provider, emphasizing that they are separate, distinct, or overlying another underlying diffuse brain disease (e.g., Alzheimer’s).

Similarly, the National Institute of Neurological Disorders and Stroke states that encephalopathy is a term for any diffuse disease of the brain that alters brain function or structure; access this at http://tinyurl.com/NINDSencephalopathy. The hallmark of encephalopathy is an altered mental state.

There is a myriad of brain diseases, many of which have names (e.g., Alzheimer’s disease, Lewy body dementia, normal pressure hydrocephalus, and Jakob-Creutzfeldt disease) that are distinct disease entities whose labels describe the brain’s pathology and clinical manifestations. I personally believe that if the patient’s manifestations can be explained solely by a named brain disease, the term "encephalopathy" is integral to that named brain disease, given that the name is more specific than the term.

The ICD-10-CM Index to Diseases has similar examples, such as hepatic encephalopathy being classified as hepatic failure; in this circumstance, another code for encephalopathy would not be coded if the mental status abnormality is only due to hepatic failure.

Therefore, if encephalopathy is documented without linkage to any condition, a query is needed to determine its underlying cause. If it is due to a named disease not in the ICD-10-CM Index to Diseases under the key term encephalopathy, the underlying disease (e.g., UTI) is coded first, followed by G94 (other disorders of brain in diseases classified elsewhere), which is per the Excludes1 note for G93.4 (other and unspecified encephalopathy).

That’s not to say that a patient with a preexisting brain disease cannot have another superimposed process, which, if clinical indicators are present, should be defined, diagnosed, and documented by the physician. The ICD-10-CM Index to Diseases outlines many of these, such as toxic, metabolic, toxic-metabolic, hepatic, anoxic, and other types of encephalopathy. Definitions include:

• Metabolic encephalopathy is a specified altered mental status due to a metabolic issue, such as hypercapnia (e.g., carbon dioxide narcosis), hyponatremia, pancreatitis, uremia, and the like.
• Toxic encephalopathy is a diffuse brain dysfunction due to an adverse effect or a poisoning of a medication. Note that the ICD-10-CM Index to Diseases states that any encephalopathy due to a medication is coded to G92 (toxic encephalopathy), and that G92 has a code first instruction for any poisoning (T51?T64), which includes alcohol.
• Toxic metabolic encephalopathies, which encompass delirium and the acute confusional state, are an acute condition of global cerebral dysfunction in the absence of primary structural brain disease. These are coded as G92 (toxic encephalopathy), unless the physician further specifies the toxic or metabolic issue. Queries regarding the definitions of metabolic or toxic etiologies are often required. While I don’t like this term, preferring to use the word "toxic" or "metabolic" alone, toxic-metabolic does exist in the clinical literature and coding nosologies. Learn more at http://www.tinyurl.com/toxicmetabolicencephalopathy.
• Hepatic encephalopathies are due to hepatic failure and are coded as such. In ICD-9-CM, all hepatic ­encephalopathies are MCCs; however, in ICD-10-CM, hepatic encephalopathy is only an MCC if associated with coma or if the hepatic failure is described as acute or subacute (less than six months in duration). Coding Clinic, Second Quarter 2016, emphasized that hepatic encephalopathy is not coded as coma unless documented by the provider as such, and if clinically valid (e.g., the patient is unconscious).
• Hypoglycemic encephalopathy is listed as E16.2 (hypoglycemia, unspecified) in the ICD-10-CM Index; however, Coding Clinic, Third Quarter 2015, advised that encephalopathy due to hypoglycemia in a diabetic should be coded using E11.649 (Type 2 diabetes mellitus with hypoglycemia without coma) as the principal diagnosis, with G93.41 (metabolic encephalopathy) as an additional diagnosis. I have been told by Coding Clinic that the Editorial Advisory Board is revisiting this issue. Stay tuned for future Coding Clinic articles to see if they reverse this opinion (I think they should).

Let us at BCCS know how you’re faring with encephalopathy, especially as you write appeals.

Editor’s note: Dr. Kennedy is a general internist and certified coder, specializing in clinical effectiveness, medical informatics, and clinical documentation and coding improvement strategies. Contact him at 615-479-7021 or at [email protected]. Advice given is general. Readers should consult professional counsel for specific legal, ethical, clinical, or coding questions. For any other questions, contact editor Amanda Tyler at [email protected]. Opinions expressed are that of the author and do not necessarily represent HCPro, ACDIS, or any of its subsidiaries.

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