Inborn errors of metabolism: Difference between revisions
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*Newborn screening varies by state | *Newborn screening varies by state | ||
*May present as late as early childhood | *May present as late as early childhood | ||
*Clinical manifestations are due to accumulation of toxic metabolites | |||
*Must rule-out sepsis (more common in these pts) | |||
==Diagnosis== | ==Diagnosis== | ||
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* Unusual odors | * Unusual odors | ||
* Hypotonia | * Hypotonia | ||
===Diagnosis=== | |||
*Encephalopathy | |||
*Hypoglycemia | |||
*Hepatic dysfunction | |||
*Nonspecific complaints: lethargy, irritability, N/V | |||
==Work-Up== | ==Work-Up== | ||
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*Lactate | *Lactate | ||
*Ketones | *Ketones | ||
===Work-Up=== | |||
*Glucose level | |||
*UA (ketones) | |||
*Chemistry | |||
**Anion gap a/w organic acidemias | |||
*LFT | |||
*Ammonia | |||
**Should be <200 in normal neonate (higher suggests urea cycle disorders) | |||
*Lactate | |||
*VBG | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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* Consider L-carnitine in conjuction with specialist, as some diseases may respond (but has side effects) | * Consider L-carnitine in conjuction with specialist, as some diseases may respond (but has side effects) | ||
*If seizing: consider Vit B6/pyroxidine | *If seizing: consider Vit B6/pyroxidine | ||
===Treatment=== | ===Treatment=== | ||
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***Give mannitol 0.5gm/kg IV/IO | ***Give mannitol 0.5gm/kg IV/IO | ||
***Do not give steroids (worsens hyperammonemia) | ***Do not give steroids (worsens hyperammonemia) | ||
==See Also== | |||
*[[Neonatal Resuscitation]] | |||
[[Category:Peds]] | |||
[[Category:Endo]] | |||
Revision as of 07:45, 1 May 2015
Background
- Suspect in any sick neonate
- Newborn screening varies by state
- May present as late as early childhood
- Clinical manifestations are due to accumulation of toxic metabolites
- Must rule-out sepsis (more common in these pts)
Diagnosis
Exam and history:
- Lethargic (2/2 hyperammonia encephelopathy)
- Nausea/vomiting
- Difficulty feeding
- Seizure
- Unusual odors
- Hypotonia
Diagnosis
- Encephalopathy
- Hypoglycemia
- Hepatic dysfunction
- Nonspecific complaints: lethargy, irritability, N/V
Work-Up
- Ammonia
- Elevated ammonia is common finding
- Chemistry
- May see hypoglycemia, metabolic acidosis
- Lactate
- Ketones
Work-Up
- Glucose level
- UA (ketones)
- Chemistry
- Anion gap a/w organic acidemias
- LFT
- Ammonia
- Should be <200 in normal neonate (higher suggests urea cycle disorders)
- Lactate
- VBG
Differential Diagnosis
Sick Neonate
THE MISFITS [1]
- Trauma
- Heart
- Congenital heart disease
- Hypovolemia
- Endocrine
- Metabolic
- Sodium
- Calcium
- Glucose
- Inborn errors of metabolism
- Seizure
- Formula / feeding problems
- Intestinal Disasters
- Toxin
- Sepsis
Treatment
- Must stop catabolism and acculmulation of toxins/ammonia
- IVF with Dextrose at 1-1.5x maintenace
- Stop feeding
- Dialysis (ammonia >500)
- NaBicarb if acidotic
- Consider L-carnitine in conjuction with specialist, as some diseases may respond (but has side effects)
- If seizing: consider Vit B6/pyroxidine
Treatment
- NS 20 mL/kg boluses
- Increase renal excretion of toxic metabolites
- Keep NPO
- Removes potential inciting metabolic substrates
- Provide D10 at 2x usual maintenance rates
- Hyperammonemia
- <500
- (Na phenylacetate & Na benzoate) 250mg/kg in D10 over 90min; then 250 mg/kg/d infusion
- Arginine 210mg/kg IV/IO in D10 over 90min; then 210 mg/kg/d infusion
- >600
- Dialysis
- <500
- Cerebral edema
- Hyperammonemia is risk factor
- Give mannitol 0.5gm/kg IV/IO
- Do not give steroids (worsens hyperammonemia)
- Hyperammonemia is risk factor
See Also
- ↑ Brousseau T, Sharieff GQ. Newborn emergencies: the first 30 days of life. Pediatr Clin North Am. 2006 Feb;53(1):69-84, vi.