TABLE 91.5 ETIOLOGY OF ACUTE LIVER FAILURE BY AGE GROUP Less than yr (%) >1 yr (%) Metabolic a (42) Unknown (47) Neonatal hemochromatosis (16) Undetermined (16) Viral hepatitis Non-A and non-B (27) Hepatitis A (10) Viral hepatitis (15) Hepatitis B (4) Other (10) Drug induced b (10) Other (2) a Type tyrosinemia, mitochondrial, urea cycle disorder, galactosemia, fructose intolerance amanita, isoniazid, valproic acid Adapted from Cochran JB, Losek JD Acute liver failure in children Pediatr Emerg Care 2007;23(2):129–135 b Acetaminophen, The development of hepatic encephalopathy (HE) is not seen in children as frequently as in adults, but when seen, is more common in patients with non– acetaminophen-induced ALF The Pediatric Acute Liver Failure Study Group evaluated children with ALF in North America and Europe and found that on presentation 57% of nonacetaminophen and 40% of acetaminophen groups had clinical evidence of HE Clinical Considerations Clinical Recognition Patients often not exhibit serious clinical features of ALF Patients may present with nonspecific prodromal symptoms or in septic shock Often children present with multisystem disease or sepsis, making the diagnosis of primary ALF challenging Adult definitions, which rely on HE, are often not reliable in children Triage Considerations Many patients simply present with nonspecific prodromal symptoms such as fatigue, nausea, and vomiting Others may present in shock with multisystem organ failure As with any life-threatening condition, patients should be triaged and treated accordingly