tailieunhanh - Ebook The Washington manual of critical care (3/E): Part 2

(BQ) Part 2 book “The Washington manual of critical care” has contents: Intracerebral hemorrhage, acute ischemic stroke, status epilepticus, acute spinal cord disorders, transfusion practices, critical care rheumatology, the acute abdomen, and contents. | SECTION XII HEPATIC DISEASES 45 Acute Liver Failure Claire Meyer and Jeffrey S. Crippin Acute liver failure (ALF) is characterized by coagulopathy, encephalopathy, and severe hepatic injury in patients without chronic liver disease (Table ). Exceptions to the absence of pre-existing liver disease include autoimmune hepatitis and Wilson’s disease, if the disease has only been recognized within the last 26 weeks. Approximately 2000 cases of ALF are reported per year in the United States. CAUSES AND DIAGNOSIS Determining the cause of ALF is imperative, since some etiologies dictate specific treatments. In a prospective multicenter study of 308 patients (1998 to 2001) by the Acute Liver Failure Study Group, the following causes were most frequently identified: acetaminophen overdose (39%), indeterminate (17%), idiosyncratic drug reactions (13%), and viral hepatitis (hepatitis A virus or hepatitis B) (11%). Table outlines the possible causes of ALF, as well as the studies needed to evaluate patients for each etiology. On presentation, initial laboratory analysis should include a complete blood count, basic metabolic panel, liver chemistries, magnesium, phosphate, prothrombin time, lactic acid, arterial blood gas, ammonia, acetaminophen level, acute viral hepatitis panel, toxicology screen, ceruloplasmin level, antinuclear antibodies, antismooth muscle antibodies, HIV status, and a pregnancy test (if applicable). ETIOLOGY-SPECIFIC MANAGEMENT OF ACUTE LIVER FAILURE (See Algorithm ) Acetaminophen Toxicity As acetaminophen toxicity is the leading cause of ALF in the United States, clinicians should have a high index of suspicion for acetaminophen overdose, particularly when there is inadequate knowledge of the circumstances preceding a patient’s presentation to the hospital. N-acetylcysteine (NAC) therapy is indicated when acetaminophen-related ALF is known or suspected, regardless of the grade of encephalopathy, and should be initiated as soon after .