the emergency department Empiric therapy for sepsis or urinary infection is often warranted, pending culture results EVALUATION OF THE OLDER CHILD In the evaluation of conjugated hyperbilirubinemia beyond infancy, it is necessary to know if there has been exposure to an infectious agent or if the potential for sexual or vertical transmission of infections such as hepatitis or human immunodeficiency virus exists Other risk factors for hepatitis (e.g., needle sticks, hemodialysis, transplant, transfusion of blood products, or factor use) need to be elicited The physician should also ask about possible exposure to industrial toxins or foods previously implicated in hepatic injury (e.g., carbon tetrachloride, yellow phosphorus, tannic acid, alcohol, mushrooms of the Amanita species) The emergency provider must inquire about use of hepatotoxic medications including acetaminophen, salicylates, nonsteroidal anti-inflammatory drugs, iron salts, erythromycin, ceftriaxone, rifampin, nitrofurantoin, oxacillin, tetracycline, trimethoprim-sulfamethoxazole, ketoconazole, diphenylhydantoin, isoniazid, and chlorpromazine Further studies to consider include infectious titers, thyroid studies, autoimmune antibodies, plasma amino acids, urine organic acids, PI phenotyping, hemoglobin electrophoresis, iron profile, sweat testing, and ceruloplasmin These are best undertaken in consultation with a hepatologist or gastroenterologist (see Chapter 91 Gastrointestinal Emergencies ) LIFE-THREATENING CAUSES NOT TO MISS Acute Liver Failure Acute liver failure presents with both liver inflammation and dysfunction, and can be quite severe and progress rapidly to shock and multiorgan failure The most common etiologies are toxin related (such as acetaminophen poisoning), infection, and idiopathic Signs of acute failure include coagulopathy with elevated PT and PTT levels, and hepatic encephalopathy with an elevated ammonia level Symptoms include vomiting, bruising, abdominal pain, jaundice, rash, and altered mental status Common complications include gastrointestinal bleeding, electrolyte imbalances, renal failure, infection, and cerebral edema Aggressive therapy is needed as soon as acute liver failure is identified, and includes supportive care to maintain cardiac, cerebral, renal, and pulmonary function N-acetylcysteine (NAC) should also be given in cases of acetaminophen toxicity Procoagulation blood products are not necessarily recommended, because even though patients with acute liver failure have low levels of