variable and has not been shown to correlate well with severity of the disease Ammonia levels more than 300 g/L have been shown to be an indicator of a poor prognosis The PT is elevated by more than 50% in at least one-half of the patients, although clinical bleeding is rare and evidence of disseminated intravascular coagulation is absent The level of serum bilirubin rarely exceeds mg/dL Hypoglycemia is rare, except in children who present in coma and in infants younger than year, in whom the incidence is reported to be as high as 70% to 80% Azotemia and ketonuria are common, secondary to starvation and dehydration from vomiting and poor oral intake Patients most often have a mixed respiratory alkalosis and mild metabolic acidosis The metabolic acidosis correlates with the level of ammonia elevation and reflects the degree of mitochondrial dysfunction Once the diagnosis is made, immediate plans to admit the child to an ICU should be made, because the progression of the encephalopathy may be rapid, resulting in increased morbidity and mortality Increased ICP secondary to cerebral edema is the major factor contributing to morbidity and mortality With the ability to monitor ICP, numerous different invasive therapies have been introduced in an attempt to rapidly reduce and control cerebral edema However, none of these therapies, including hyperventilation and muscle paralysis using neuromuscular-blocking drugs, hyperosmolar agents, high-dose barbiturates, exchange transfusions, or hypothermia, have been clearly proven to protect the brain from progressive ischemic insult Ultimately, the management of Reye syndrome is supportive because no specific curative therapy is currently available Finally, it is important to note that there are multiple diseases secondary to inborn errors of metabolism (mostly mitochondrial) that present in a very similar fashion to Reye syndrome Given the rarity of Reye syndrome, any child who is suspected of having Reye syndrome should have a thorough metabolic evaluation Suggested Readings and Key References Overview Thompson DA, Eitel D, Fernandes CM, et al Coded chief complaints– automated analysis of free-text complaints Acad Emerg Med 2006;13(7):774–782