When a patient was admitted after taking too much medication with alcohol, the hospital reported a secondary diagnosis of toxic encephalopathy on the claim. The physician had documented the patient’s altered mental status—a hallmark of any form of encephalopathy, which is a brain disorder—but the auditor for the commercial payer nixed the code (G92). In the denial, the auditor said altered mental status was a sign and symptom of a drug overdose and shouldn’t be coded, citing the Official Guidelines for Coding and Reporting—although the hospital ultimately proved the auditor wrong.

That has a familiar ring to it because encephalopathy has attracted a lot of attention from auditors, along with sepsis (RMC 1/15/18, p. 1) and a handful of other secondary diagnoses. They are downcoding MS-DRGs by rejecting secondary diagnoses, which translate into complications and comorbidities (CCs) or major CCs that affect MS-DRG reassignment—usually for the worse in terms of reimbursement. But sometimes auditors overlook documentation that supports the secondary diagnosis or misinterpret coding and clinical guidelines, says Denise Wilson, vice president of AppealMasters in Towson, Md. That gives hospitals an opening to overturn the denials, she says. “Don’t take denials at face value,” she advises.

The hospital in the toxic encephalopathy case took that advice to heart. In its appeal, the hospital presented guidance from Coding Clinic, the American Hospital Association’s newsletter. For example, in the first quarter 2017 edition, Coding Clinic was asked how to code a patient with bipolar disorder who presents to the emergency room with altered mental status after taking too much lithium. The physician’s diagnosis is toxic encephalopathy due to lithium toxicity. In its answer, Coding Clinic said, “Assign code T43.592A, poisoning by other antipsychotics and neuroleptics, intentional self-harm, initial encounter, as the principal diagnosis. Code G92, toxic encephalopathy, should be assigned as an additional diagnosis…”