insulin (starting at 0.01 units/kg/hr) should be used while carefully monitoring serum glucose instead of decreasing or stopping dextrose-containing fluids Hypotonic fluid overload should be avoided, particularly in patients with hyperammonemia, because this could result in cerebral edema Increased intracranial pressure in patients with hyperammonemia should not be treated with steroids or mannitol Steroids increase catabolism and can therefore worsen hyperammonemia Mannitol has not been shown to be effective Hypertonic saline can be used TABLE 95.7 EMERGENT TREATMENT Access and establish airway, breathing, circulation Fluid boluses normal saline, avoid lactated Ringer’s Avoid hypotonic fluid load due to risk of cerebral edema, particularly if hyperammonemia Discontinue intake of offending agents, provide adequate glucose to prevent catabolism NPO (especially no protein, galactose, or fructose) Glucose for hypoglycemia, 0.25–1 g/kg (i.e., D10 neonates; D10 or D25 infant, child) D10 to D15 with electrolytes: 8–12 mg/kg/min IV at 1–1.5 × maintenance to maintain serum glucose level at 120–170 mg/dL If necessary, treat hyperglycemia with insulin to further prevent hyperglycemia Correct metabolic acidosis (pH 300 μg/dL if concentration is rising, prepare for possible dialysis for ammonia >200–250 μg/dL, engaging receiving dialysis unit/facility as soon as possible If dialysis not immediately available or levels >100–125 μg/dL, use sodium phenylacetate, sodium benzoate as Ammonul (Ucyclyd Pharma, 1-888-829-2593) If 300 μg/dL if concentration is rising, prepare for possible dialysis for ammonia >200 to 250 μg/dL, engaging receiving dialysis unit/facility as soon as possible If dialysis is not immediately available or levels are higher than 100 to 125 μg/dL but lower than 200 μg/dL, pharmacologic agents for ammonia removal should be administered to patients with known or suspected urea cycle defect Sodium phenylacetate and sodium benzoate, available in combination as the preparation Ammonul, 100 mg each per mL (Ucyclyd Pharma, Inc., Scottsdale, AZ; 1-888-829-2593) eliminates nitrogen by an alternative pathway that does not rely on an intact urea cycle Ammonul does not remove ammonia rapidly enough to serve as primary therapy in patients with severe hyperammonemia Arginine, which enhances urea cycle activity in patients with most urea cycle defects, should be administered in the face of hyperammonemia using arginine HCl 10% at a dose of 200 to 600 mg/kg IV over 90 to 120 minutes, followed by the same dose over 24 hours Arginine HCl can be mixed with Ammonul If Ammonul/arginine HCl is being administered, the hourly infusion rate of maintenance fluids should be reduced by the volume of Ammonul/arginine HCl being given Given the high concentration of sodium in Ammonul and chloride in arginine HCl, extreme caution must be taken if administering other sodium chloride–containing fluids Sodium phenylacetate may deplete potassium Potassium should be replaced as potassium acetate Ondansetron (0.15 mg/kg up to every hours) should be administered for vomiting and/or prophylactically if treating with Ammonul To assess patient response to treatment, ammonia, electrolytes, and blood gas should be monitored every hours Usually, to days of therapy is necessary For seizures unresponsive to conventional anticonvulsants, empiric therapy with pyridoxine (B6 ; 100 mg IV), folic acid (leucovorin; 2.5 mg IV), and/or biotin (10 to 40 mg delivered by nasogastric tube) should be considered in neonates and infants to treat a possible cofactor-responsive IEM While there are other disease-specific pharmacologic agents, their administration is rarely indicated in the ED L carnitine may be administered in acutely life-threatening situations for suspicion of disorders associated with carnitine deficiency, but its use is controversial and consultation with an IEM specialist is recommended L -carnitine is given at a dose of 25 to 50 mg/kg over to minutes or as an infusion added to the maintenance fluid, followed by 25 to 50 mg/kg over 24 hours, maximum g/day Given that some IEMs are associated with increased risk of infection and that serious bacterial infection can precipitate metabolic crisis, antibiotics should be considered for any patient of concern for possible serious bacterial infection Fresh frozen plasma may be indicated for patients with coagulopathy KNOWN IEM Goals of Treatment For the child with known IEM and acute decompensation, goals of treatment are to expediently and proactively evaluate for and manage cardiopulmonary decompensation and IEM-specific metabolic derangements, and restore and maintain hydration The child with an IEM in the ED for conditions that could precipitate decompensation, such as acute infectious process, but presently without acute manifestations of their IEM should receive aggressive therapy to prevent metabolic derangements and decompensation The family may have an emergency treatment plan with them developed by an IEM specialist, specifically for their child Use of clinical pathways for treatment of patients with an IEM in the ED has been shown to improve timeliness and effectiveness of care All patients with decompensation should be admitted to the hospital, and there should be a low threshold for admitting any patient at risk for acute decompensation CLINICAL PEARLS AND PITFALLS Acute decompensations are most commonly seen with tyrosinemia, organic acidemias, urea cycle defects, fatty acid oxidation defects, and galactosemia Early recognition of acute metabolic decompensation is critical for effective management of patients with known IEM A history of physiologic stress, such as intercurrent illness or recent surgery, or noncompliance with diet may precipitate symptoms and warrants preventative management Current Understanding Manifestations of IEM are disease specific but also patient specific Understanding of these specifics, as well as advances in treatment, will most expeditiously and effectively guide evaluation and management Clinical Considerations Triage Patients with known IEM associated with potential for acute life-threatening decompensation should be triaged expeditiously Many families have treatment pathways in hand (or delineated in EMR) to optimize care ( Table 95.8 ) AMINO ACID DISORDERS Goals of Treatment Treatment of children with amino acid disorders includes avoiding dietary intake of the offending amino acid(s), and correcting acute metabolic and physiologic derangements Current Understanding Most amino acid disorders not cause acute decompensation A notable exception is tyrosinemia type I, a disorder of phenylalanine and tyrosine metabolism that initially causes liver failure and later hepatocellular carcinoma It usually presents in early infancy but can present in the neonatal period Clinical Considerations Assessment Clinical features include lethargy, vomiting, diarrhea, failure to thrive, hypoglycemia, jaundice, ascites, edema, bleeding, and renal tubular acidosis Patients, particularly neonates, may have sepsis Infants and children, in addition to manifestations seen in the neonate, may have hepatosplenomegaly, rickets, hypotonia, and neurologic deficit CBC, electrolytes, glucose, phosphate, calcium, albumin, PT, PTT, and blood gas should be obtained upon presentation for illness As clinically indicated, cultures and lactate to evaluate for sepsis should be sent Management To treat dehydration, normal saline bolus(es), 10 mL/kg for neonates and 20 mL/kg for infants and children should be administered If the patient is hypoglycemic a bolus of 0.25 to g/kg as D10 for neonates and D10 or D25 for infants and children should be given After administration of bolus fluid and correction of any hypoglycemia, D10 in ½ normal saline should be continued at to 1.5 times maintenance to maintain serum glucose levels at 120 to 170/mg/dL Insulin is sometimes required to prevent catabolism in which case additional dextrose is often required Stable patients without decompensation and able to feed must avoid offending amino acids Formula brought by the family may need to be used until the appropriate formula can be obtained for the patient within the hospital ... specialist is recommended Adapted from Weiner DL Inborn errors of metabolism In: Aghababian RV, ed Emergency Medicine: The Core Curriculum Philadelphia, PA: Lippincott-Raven; 1999:707 Hemodialysis is... aggressive therapy to prevent metabolic derangements and decompensation The family may have an emergency treatment plan with them developed by an IEM specialist, specifically for their child