According to the CDC, 4.5 million Americans have chronic liver disease and almost 48,000 die from it each year. Compare that with less than 43,000 deaths per year from breast cancer. Among persons age 45 and older the incident rate of death ranges between 26 and 30 per 100,000 per year depending on age. Complete and specific documentation of liver failure is essential for correct coding and reimbursement.
Liver failure may be either acute or chronic. Acute liver failure refers to the development of severe acute liver injury with encephalopathy and impaired synthetic function (international normalized ratio ≥1.5) in a patient without cirrhosis or pre-existing liver disease. Other terms used to describe this condition include acute hepatic necrosis, fulminant hepatic failure, fulminant hepatic necrosis, and fulminant hepatitis. Shock liver, also known as ischemic hepatitis, is a term that describes acute liver failure due to hypotensive shock.
Acute liver failure can be categorized based on the duration of illness, as hyperacute (<7 days), acute (7 to 21 days), or subacute (>21 days and <26 weeks). Many patients suffer severe liver damage causing cirrhosis and progressing to chronic liver failure. ICD-10 codes identify acute, subacute, and chronic liver failure with or without cirrhosis, and in some cases, whether ascites or coma is present. Liver failure becomes chronic, typically with cirrhosis, when it has been present for 26 weeks or more. Progression of acute liver failure to chronic, especially from viral hepatitis, is not unusual.
Hepatitis viruses are the most common cause of acute liver failure, but drugs like acetaminophen and toxins such as carbon tetrachloride or Amanita mushrooms are also important causes. Less common are idiosyncratic drug reactions and autoimmune hepatitis. Complications of acute liver failure may include acid-base and electrolyte disorders, cerebral edema, and pulmonary edema. Acute kidney injury commonly occurs in patients with acute liver failure.
According to the NIH, the most common cause of chronic liver failure is chronic alcohol abuse. Another is nonalcoholic fatty liver disease (recently renamed metabolic-associated fatty liver disease) commonly occurring in obesity, type 2 diabetes, and hypertriglyceridemia, which may progress to the more serious nonalcoholic steatohepatitis.
Two categories of ICD-10 codes for liver failure specifically identify alcohol and toxic substances as causes (Table 1), and there are many specific codes for liver failure based on the causes and complications (Table 2). In cases where the underlying cause of liver failure is not included as part of a combination code, such as viral hepatitis, the underlying cause should also be documented and coded. Documentation and coding should include as much specificity as possible, citing all related liver disorders and any complications.
Portal hypertension is nearly always present in chronic liver failure and can result in esophageal varices, which are highly prone to severe hemorrhage. Liver failure may also be complicated by chronic kidney disease (hepatorenal syndrome). Hepatocellular carcinoma occurs almost exclusively in the setting of chronic liver disease and cirrhosis. Other complications include ascites, peripheral edema, splenomegaly, anemia, and thrombocytopenia. Acute-on-chronic liver failure represents a sudden hepatic decompensation in patients with pre-existing chronic liver disease.
Hepatic encephalopathy (acute or chronic) is primarily due to systemic accumulation of ammonia and presents as variable degrees of altered mental status, behavioral disturbances, and decreased consciousness, which can manifest as lethargy, confusion, delirium, psychosis, or ultimately coma. A Glasgow Coma Scale score should be obtained at least once, if not daily, in patients with hepatic encephalopathy.
Hepatic encephalopathy does not have its own unique code but is included in the hepatic failure codes with or without coma. Unfortunately, this means that a patient with severe hepatic encephalopathy who is not yet comatose will be classified the same as patients with hepatic failure who are not actively encephalopathic. The severity, complexity, and resource consumption of these encephalopathic patients are not accounted for by ICD-10 codes or diagnosis-related groups.
In summary, liver failure may be either acute or chronic. Many ICD-10 liver failure codes are combination codes that depend on the acuity and cause of liver failure, as well as the presence of cirrhosis, coma, and occasionally ascites. Documentation and coding should include as much specificity as possible, mentioning all related liver disorders and any complications.