Ch 25 - Endocrine & metabolic disorders Flashcards Preview

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Flashcards in Ch 25 - Endocrine & metabolic disorders Deck (23)
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1

Classification of Diabetes:

Type 1, 2, 3, 4 

 

  1. Autoimmune B cell destruction > insulin deficiency (miost childhood diabetes)
  2. Insulin resistance which eventually leads to b cell failure; usually obesity related, +ve FH, Indians 
  3. Other specific types e.g. MODY (genetic defect in B-cell function due to glucokinase or TF mutations), genetic insulin defects, infections, drugs etc.
  4. GDM 

2

DM features (3)

  1. polyuria + polydipsia
  2. weight loss
  3. DKA 

3

DM Ix (4)

  • Random blood sugar > 11.1 
  • Fasting blood sugar > 7 
  • Raised HbA1c 
  • Signs of IR e.g. acanthosis nigricans (dark velvety skin on neck and armpits) 
  •  

4

DM: management (always education 1st): insulin types (2), admin (2), regimens (2)

Insulin:

  • Short acting soluble human insulin e.g. actrapid, Humulin S, novorapid (before meals)
  • Intermediate acting e.g. insulatard, humulin I
  • Long acting e.g. Lantus 

Admin:

  • subcut > rotate sites to prevent lipoatrophy
  • insulin pumps 

Regimens:

  • twice daily: mixed in morning & evening (short + intermediate)
  • Thrice daily: long acting at night, mixed in morning, short in evening 

5

DKA: features (5), management (4)

Features: 

  • dehydration, vomiting
  • sweet smelling breath
  • abdo pain
  • Kussmaul breathing - due to acidosis 
  • coma/ shock 

Management:

Admit > IV 0.9% saline 10ml/kg (not 20 because of risk of cerebral oedema) + insulin infusion + potassium

Re-establish oral fluids + subcut insulin + treat underlying cause

6

Hypoglycaemia: features (4), Rx (3)

<4 mmol/l:

  • hunger, stomache ache, sweatiness, faintess, 'wobbly legs'
  • pallor, irritability, seizures 

Rx:

  • glucose tabs/ sugary drink if severe give IM glucagon
  • Then give complex carb e.g. biscuit/ sandwich 

7

Causes of hypoglycaemia (4)

insulin excess:

  • e.g. DM
  • insulinoma

without hyperinsulinaemia:

  • ketotic hypoglycaemia of childhood (due to short period of starvation)
  • in born errors of metabolism e.g. glycogen storage disorder
  • hormonal def e.g. low GH, low ACTH, CAH, Addison

8

Ix of hypoglycaemia (4), management (2)

GH, IGF-1, cortisol, insulin, C-peptide, ketones, lactate, pyruvate

Rx:

  • IV 10% dextrose slowly (prevent cerebral oedema)
  • if fail to respond > IM glucagon 

9

Congenital hypothyroidism: causes (4), features (5), Ix (1), Rx (1)

Causes: agenesis/maldescent, dyshormonegenesis, idodine def, TSH def

Features: hoarse cry, goitre, coarse facies, cool peripheries, constipation, macroglossia, jaundice

Ix: Guthrie test (raised TSH)

Rx: T4

10

Hyperthyroidism: cause (1), features, Ix (2), Rx (4)

Cause - graves

F - similar to adults; exopthalmus less common

Ix - raised T4/3, low TSH, anti-TPO/ TG abs

Rx: 

  • propyluracil/ carbimazole
  • BB
  • thyroidectomy
  • radioidoine 

11

Hypoparathyroidism: main cause in infants (1), chilren (1)

Pseudohypoparathyroidism: serum Ca/PO4 & PTH (high/low or normal), features (4)

Pseduopseudohypoparathyroidism: serum Ca/PO4 & PTH (high/low or normal)

Usually due to DiGeorge in infants & Addisons in children (high Ca low PO4 > spasms fits, diarrhoea)

Pseudo - end organ resistance to PTH  (mutation in signaling molecule) > serum Ca/ PO4 abnormal, PTH may be normal/high. Features include: short stature, obesity, subcut nodules, short 4th/5th metacarpals.

Pseudopseudo - clin features of pseudoHPT, but Ca/PO4/PTH all normal 

12

Rx of Hypocalcaemia (3)

  • Iv 10% Ca gluconate 
  • oral Ca  
  • high dose vit D

13

Hyperparathyroidism features (4), Rx (3)

F: constipation, lethargy, anorexia, polyuria, polydipsia, bony phalange erosions

Rx - bisphosphonates, rehydration, diuretics

 

14

Adrenal cortical insufficiency: causes (3), features (5)

CAH, Addisons, hypopituitarism

Features

  • salt losing crisis
  • hypotension
  • hypoglycaemia
  • chronic ill health + pigmentation
  • undescended testicle - CAH

 

15

Adrenal cortical insufficency: Ix ( 5), Rx (4) 

Hyponatremia, hyperkalaemia, acidosis, hypoglycaemia

Low plasma cortisol, high plasma ACTH (unless hypopituitarism), SynACTHen test - plasma cortisol remains low 

Rx: crisis > IV saline + glucose + glucocorticoid + mineralocorticoid 

16

Cushing syndrome: Causes (3), features (5), Ix (3), Rx (3)

C:

  1. long term glucocorticoids e.g. for asthma/ nephrotic syndrome
  2. pituitary adenoma
  3. ectopic tumours
  4. adrenocortical tumour

F: short stature, obesity, striate, HTN, bruishing, mypoathy, osteopenia

Ix: 

  1. 24hr urinary free cortisol high
  2. high dose Dex suppression failure 
  3. CT/ MRI

Rx:

  1. unilateral adrenalectomy
  2. radiotherapy
  3. transphenoidal resection 

17

PKU: cause (1), features (4), Rx (1)

Cause: deficiency in phenylalanine hydroxylase 

F: usually picked up in guithrie test; else present within 1st year with developmental delay, musty odour, usually blue-eyed fair haired, seizures, eczema

Rx - restriction of dietary phenylalanine (but enough to ensure neuro development) 

18

Homocystinuria: cause (1), features (5), Rx (2)

Cause - cystathionine synthetase def; which results in failure of methionine metabolism > homocysteine accumulation

F - developmental delay, ocular lens subluxation (ectopia lentis), LD, psych disorders, convulsions, marfanoid habitus, thromboembolic episodes, malar flush

Rx: pyridoxine (50% respond) if not > low methionine diet + supplement with cysteine + betanine 

 

19

Tyrosinaemia (type 1): cause, features (2), Rx (2)

Cause - autosomal recessive def in fumarylacetoacetase

F - accumulation of toxic metabolites > liver failure + renal damage > Fanconi syndrome

Rx - NTBC (a drug) which inhbitis enzyme that catabolizes tyrosine so must have a low tyrosine & phenylalanine diet 

20

Galactosaemia: definition, features (5), rx(1)

D - Gal-1-PUT deficiency - essential for galactose metabolism

F - so when lactose-containing milk feeds introduced affected infants feed poorly, vomit, develop jaundice, hepatosplenomegaly & liver failure. Cataracts if untreated. LDs even if treated early

M - lactose + galactose free diet for life 

21

Familial hypercholesterolaemia: definition, features (3), Ix (1), Rx (2)

D - autosomal dominant disorder due to LDL receptor defect

F - xanthomata on skin + tendon; CHD by 50-60, if homozygous CVD in 2nd decade

Ix - serum cholesterol > 3.3 

Rx - statins if LDL high + FH of CVD; fibrates 

22

What is Glycogen storage disorder

Recessive disorder whih have specific enzyme defects that prevent mobilization of glucose from glycogen > resulting in abnormal accumulation of glycogen in liver and/or muslce. 

23

Glycogen storage disorders: type 1, 2, 3, 5 

Type 1 (von Gierke): G6P deficiency > enlarged liver and kidneys (which causes truncal obesity), growth failure, hypoglycaemia, doll facies, hypotrophic muscles (good prognosis)

Type 2 (pompe): lysosomal alpha glucosidase def: hypotonia, cardiomegaly, death from HF. Can be management with enzyme replacement myzozyme 

Type 3 (cori): amylo 1,6 glucosidase def: milder features of type 1. managed with high protein diet to prevent growth retardation

Type 5 (mcardle): presentas in childhood, temp weakness, muscle cramps post-exercise, myoglobulinuria