What is the difference between delirium and encephalopathy? This is a common discussion among coders and clinical documentation improvement (CDI) professionals alike.
Usually when a question like this comes up, the solution is simple: check the literature. Unfortunately, the information is somewhat contradictory, so we continue the debate while Recovery Auditors (RACs) take advantage, leveraging this confusion as a means to miraculously cure or downgrade the severity for this patient population.
Delirium and encephalopathy often are used interchangeably in the clinical setting as well as in the research and literature. Yet for the purposes of classification and severity of illness, they do not mean the same thing. Delirium, unspecified is classified in ICD-9 as non-specific alteration of mental status (780.9), while in ICD-10 the language is “disorientation” (R41.0). When further specified as a specific type, delirium is still classified in the section of ICD-9 reserved for mental and behavioral problems (located between drug-induced mental disorders and dementia, with codes ranging from 290.x to 293.x), which is an obviously inappropriate code assignment for a patient with a brain malfunction resulting from a systemic pathological problem. Another valid argument is that “delirium” is sometimes used to describe the observable manifestations of an underlying encephalopathy. When used in this manner, the change of the diagnosis to delirium imposed by the RACs would be tantamount to suggesting that chest pain is the correct diagnosis for a patient with a documented myocardial infarction. RACs get away with this, however, because the delirium codes are not straightforward sign-and-symptom codes in the classification the way chest pain is. The advice here is to avoid using delirium in this manner, as it is not the convention.