RT Book, Section A1 Hoganson, George E. A2 Tenenbein, Milton A2 Macias, Charles G. A2 Sharieff, Ghazala Q. A2 Yamamoto, Loren G. A2 Schafermeyer, Robert SR Print(0) ID 1155427872 T1 Inborn Errors of Metabolism T2 Strange and Schafermeyer's Pediatric Emergency Medicine, 5e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9781259860751 LK accessemergencymedicine.mhmedical.com/content.aspx?aid=1155427872 RD 2024/11/02 AB Inborn errors of metabolism (IEM) that are more likely to present in the emergency department (ED) can be classified into a number of categories:Select amino acid disordersUrea cycle defectsDisorder of carbohydrate metabolismOrganic acid disordersFatty acid oxidation defectsAge of presentation is often related to the specific IEM and can vary from the newborn period to later in life, even into adulthood.With expanded newborn screening for IEM, more patients with one of these disorders will present to the ED with a known diagnosis.Patients with IEM can present with no prior history of medical problems. Precipitating events include febrile illness, gastroenteritis, poor oral intake, dietary change (increased protein intake, addition of fructose to the diet), or exercise.Clinical symptoms of IEM include vomiting, altered mental status/lethargy, seizures, hypotonia, and tachypnea.Hypoglycemia, anion gap acidosis, hyperammonemia, and ketosis are some of the metabolic consequences of IEM.General laboratory testing to consider in a patient with a suspected IEM includes glucose, ammonia, liver function, creatine kinase (CK), electrolytes, blood gas, uric acid, urinalysis, and urine-reducing substance.