Metabolic medicine Flashcards
Define hypoglycaemia
Blood glucose <2.6
What investigations would you do for hypoglycaemia?
Insulin level
c-peptide
Growth hormone level
Free fatty acid
Ketone bodies
Cortisol
What is significance of c-peptide level in context of hypoglycaemia ?
Level should be same as insulin. If LOWER than insluin level suggests child being given extra insulin. - SAFEGUARDING
What investigations would you consider for a new presentation of metabolic acidosis
Ketones!
Acylcornitine
Ammonia
Lactate
Urine organic acid
Plasma amino acids
ALWAYS CALCULATE ANION GAP
([NA+] + [K+]) - ([HCO3-] + [CL-])
Normal is 10-14
What causes metabolic acidosis with rasied anion gap?
Lactic acidosis
DKA
Poisoning with: salicylate, methanol, propylene glycol, iron, isoniazid, ethylene glycol
Renal failure
Acid producing metabolic disorders
What causes metabolic acidosis with normal anion gap?
Renal tubular acidosis
Addison’s disease
Acetozolamide use
Severe diarrhoea
Post-ureteric diversion into large bowel
Describe idiopathic ketotic hypoglycaemia
Presenting in first few years with hypoglycaemia and ketones during intercurrent illness or prolonged fast. Treat with emergency glucose and avoid fasting.
resolves by 8 years of age
Diagnosis of exclusion
Describe Glycogen storage disease 1
AR
Presents before 2 years of age with hypoglycaemia, hepatomegaly, seizure, poor growth/development
Low glucose, H lactate, ketone, and lipid.
Treat with frequent feeds and gastric feeds overnight.
Emergency feeding when unwell.
What are the lab findings of Galactosaemia
Conjugated bilirubinaemia , deranged coag and metabolic acidosis, urinary reducing substances, glycosuria, aminoaciduria, albuminuria.
Describe Galactosaemia, it’s mode of inheritance and how it usually presents
AR
Cannot metabolise galactose
Presents as jaundice, poor feeding, cataracts, e-coli sepsis
What is the treatment for Galactosaemia?
Never have galactose
Manage cataracts
Girls infertile- see endocrine
Describe Medium Chain Acyl-CoA dehydrogenase deficiency (MCAAD)
Part of neonatal screening
Can present before with poor feeding, generally unwell and seizures.
What are lab findings for MCAAD?
Non-ketotic hypoglycaemia
What is treatment for MCAAD?
Avoid prolonged fasting and take extra calories when ill
Will otherwise have normal development and growth
What test suggests MPS?
Aminoglycosides in urine
What are features of urea cycle disorders?
Poor feeding, seizures and reduced GCS in 1-5 days of life
Lab: Resp alkalosis, +++ammonia, plasma ammonia high and urinary organic acids present.
What is the treatment for urea cycle disorder?
Acute: NBM, 10% dextrose +electroyltes. Sodium benzoate + haemofiltration.
Lifelong low protein diet + ammonia scanvengers
What is the treatement for Phenylketonuria?
Low protein diet and regular phenylalanie monitoring
Describe homocystinuria
AR. In newbrn screen
Down and out lens dislocation, tall, ID, aortic and mitral valve regurg, pectus excavatum.
Needs plasma amino acid screen
What is the treatment for homocystinuria?
Pyridoxine and B6, low protein diet.
Describe Maple Syrup Urine Disease
In newborn screen
Presents as progressive encephalopathy + sweet piss. Often looks like sepiss
What are the lab findings for maple syrup urine disease?
Metabolic acidosis, rasied annion gap, +++ ammonia
Describe Leigh’s Syndrome
Mitochondrial disease
Sub-acute sclerosing encephalopathy
Presented as 2-3 yr old with developmental delay/ seizure/ myopathy
Raised lactate and classic MRI findings
