ENDOCRINOLOGY PAEDS Flashcards
Normal Blood sugar levels
4.4-6.1 mmol/l
How do children with T1DM present?
25-50% present with DKA
The rest, triad of symptoms
- Polyuria
- Polydipsia
- Weight loss
Where in pancreas is insulin and glucagon produced
Insulin: Beta cells in islets of langerhans
Glucagon: ALpha cells in islets of langerhans
?DM - investigations
Baseline bloods
Blood cultures if ?infection
HbA1c (picture of BM over the last 3 months)
TFT and thyroid peroxidase antibodies (TPO) to test for associated autoimmune thyroid disease
Tissue transglutaminase (anti-TTG) ?coeliac
Insulin antibodies, anti-GAD antibodies and islet cell antibodies (antibodies associated with the pancreas and development of type 1 diabetes)
Consequence of injecting insulin into the same spot
LIPODYSTROPHY
Subcutaneous fat hardens and prevents absorption of insulin
Basal bonus regime
Basal: LONG ACTING INSULIN (e.g. Lantas)
Bolus: SHORT ACTING INSULIN (e.g. actrapid) - usually 3 x per day in between meals
How can a child qualify for an insulin pump on the NHS
Needs to be > 12 years old
Have difficulty controlling their HbA1c
Symptoms of hypoglycaemia
Hunger, tremor, sweating, irritability, dizziness, pallor
Treatment of hypoglycaemia
Mild: Short acting glucose (e.g. lucosade) and long acting carbohydrates (e.g. biscuits/toast)
10-20g glucose
Severe:
IV 10% dextrose 100ml
IM glucagon 1mg
Macrovascular complications of DM
Coronary artery disease
Peripheral ischaemia (—>poor healing, ulcers, diabetic foot)
Stroke
HTN
Micro vascular complications
Peripheral neuropathy
Retinopathy
Kidney disease
Infection related consequences
UTI
Pneumonia
Skin/soft tissue infections
Fungal infections (Oral/vaginal candidiasis for example)
What is DKA
Ketones = water soluble fatty acids that can be used as fuel when glucose not available
They are buffered in normal non- diabetic patients, so they don’t become acidotic
T1DM —> extreme hyperglycaemic ketosis —> metabolic acidosis which is life threatening
Main 3 problems of DKA
- Ketoacidosis: initially kidneys produce bicarbonate to buffer the ketones, then this is used up and blood become acidic
- Dehydration: Hyperglycaemia overwhelms the kidneys and glucose starts being filtered into the urine. Glucose in urine draws water out with it (OSMOTIC DIURESIS) —> POLYURIA —> dehydration and polydipsia as increases thirst
- Potassium imbalance: insulin drives potassium into cells. So without serum potassium can be high, but total body potassium can be low as its not being stored. When starting insulin pt can become hypokalaemic quickly (—> arrhythmias!)
Cerebral oedema in DKA
High blood sugar in brain —> water moves from intracellular space to extracellular space —> brain cells shrink and become dehydrated
Rapid correction of dehydration and hyperglycaemia —> rapid shift in water from extracellular space to intracellular space —> oedematous
Management of cerebral oedema in DKA
Monitor neurological obs closely
Slow IV fluids
IV mannitol
IV hypertonic saline
DKA presentation
Polyuria Polydipsia N&V Weight loss Acetone smell on breath Dehydration and hypotension Altered consciousness Symptoms of an underlying trigger (e.g. sepsis)
Diagnosing DKA
HYPERGLYCAEMIA ( Blood glucose >11 mmol/l)
KETOSIS (blood ketones >3 mmol/l)
ACIDOSIS (pH <7.3)
What’s deficiency in adrenal insufficiency
Steroid hormones: particularly cortisone and aldosterone
What is PRIMARY ADRENAL INSUFFICIENCY
= ADDISON’S DISEASE
Adrenal glands have been damaged and there is reduced secretion of cortisol and aldosterone
What is SECONDARY ADRENAL INSUFFICIENCY
Inadequate ACTH stimulating the adrenal glands (aka not a problem with the glands themselves) —> reduce cortisol levels
Causes: Loss or damage to the pituitary gland - e.g. due to congenital hypoplasia, surgery, infection, radiotherapy, loss of blood supply
What is TERTIARY ADRENAL INSUFFICIENCY
Result of inadequate CRH released by HYPOTHALAMUS
E,g, patients being on long term steroids causing suppression of the hypothalamus - when exogenous steroids removed the endogenous steroids not adequately produced (LT steroids should be tapered slowly!)
Features of ADRENAL INSUFFICIENCY in babies
Lethargy Vomiting Poor feeding Hypoglycaemia Jaundice Failure to thrive
Features of ADRENAL INSUFFICIENCY in older children
N&V Poor weight gain/weight loss Anorexia Abdo pain Muscle weakness/cramps Developmental delay Addisons: bronze hyperpigmentation (high ACTH stimulates melanocytes)
ADRENAL INSUFFICIENCY: investigations
U&Es (hyponatraemia and hyperkalaemia)
Glucose (hypoglycaemia)
Cortisol, ACTH, aldosterone and renin levels (prior to administing steroids)
Primary vs secondary adrenal insufficiency
Short Synacthen Test (ACTH stimulation test) - how does it work
Ideally performed in the morning
Synacthen = synthetic ACTH
Blood cortisol measured at baseline, then 30 and 60 mins after administration
Normal: cortisol at least doubles
Abnormal: Failure for cortisol to rise or less than double baseline —> Addison’s disease (Primary adrenal insufficiency)
Adrenal insufficiency: Management
REPLACEMENT STEROIDS: Titrated to signs, symptoms, electrolytes
HYDROCORTISONE (glucocorticoid) - replaces cortisol
FLUDROCORTISONE (minceralocorticoid) - replaces aldosterone
Does increased during acute illness (to match normal steroid response)
Adrenal insufficiency: Monitoring
Growth and development BP U&Es Glucose Bone Profile Vitamin D
Adrenal insufficiency: SICK DAY RULES
- Dose of steroid needs to be increased and given more regularly during acute illness
- blood sugar monitored closely and eat carbohydrate foods regularly
- If D&V - need IM injection of steroids at home and might require admission of IV steroids
ADDISONIAN CRISIS: Presentation
Reduced consciousness
Hypotension
Hypoglycaemia, hyponatraemia, hyperkalaemia
ADDISONIAN CRISIS: Triggers
Stopping steroids
Infection/trauma/acute illness
First presentation of adrenal insufficiency
ADDISONIAN CRISIS: Management
Intensive monitoring if acutely unwell
Parenteral steroids (e.g. IV hydrocortisone)
IV fluid resuscitation
Correct hypoglycaemia
Careful monitoring of electrolytes and fluid balance
What is CONGENITAL ADRENAL HYPERPLASIA
Deficiency of the 21-hydroxylase enzyme
Causes underproduction of cortisol and aldosterone and overproduction of androgens from birth
Autosomal recessive
Action of Aldosterone
Acts on kidneys to control balance of salt and water in the blood
Released by adrenal gland in response to renin
Increases sodium re absorption into the blood and potassium secretion into urine
Aka decreases potassium and increases sodium in the blood
Pathophysiology of congential adrenal hyperplasia
Enzyme that’s deficient (21-hydroxylase) responsible for breaking down progesterone to aldosterone and cortisol
Progesterone is used to create testosterone, so more progesterone —> more testosterone as it is not able to be converted into aldosterone and cortisol
LOW CORTISOL
ABNORMALLY HIGH TESTOSTERONE
congential adrenal hyperplasia: PRESENTATION
Females: at birth present with virility’s genitalia (ambiguous genitalia) - enlarged clitoris due to testosterone levels
Severe CAH - shortly after birth present with hyponatraemia, hyperkalaemia, hypoglycaemia
Signs/symptoms: poor feeding, vomiting, dehydration, arrhythmias
congential adrenal hyperplasia: Presentation in mild cases
Symptoms/signs associated to high testosterone levels
Female pt: Tall for age, facial hair, absent periods, deep voice, early puberty
Male pt: Tall, deep voice, large penis, small testicles, early puberty
SKIN HYPERPIGMENTATION - key clue (by product of ACTH production is melanocyte stimulating hormone)
congential adrenal hyperplasia: Management
CORTISOL REPLACEMENT: usually hydrocortisone
ALDOSTERONE REPLACEMENT: fludrocortisone
Corrective surgery for females with ambiguous genitalia
What is GROWTH HORMONE DEFICIENCY?
Disruption to the growth hormone axis at the hypothalamus or pituitary gland
Explain the GROWTH HORMONE AXIS
Hypothalamic-pituitary growth axis
Growth hormone produced by the ANTERIOR PITUITARY gland —> stimulates cell reproduction and growth of organs, muscles, bones and height
Stimulates the release of INSULIN LIKE GROWTH FACTOR (IGF-1) by the liver (important for growth in children and adolescents)
CONGENITAL GROWTH HORMONE DEFICIENCY
Genetic mutation e.g. GH1 or GHRHR (growth hormone releasing hormone receptor) genes
Or empty sella syndrome (pituitary gland underdeveloped or damaged)
ACQUIRED GROWTH HORMONE DEFICIENCY
Secondary to trauma, infection, surgery etc.
HYPOPITUITARISM / MULTIPLE PITUITARY HORMONE DEFICIENCY
When the pituitary does not produce a number of hormones
Growth hormone deficiency: PRESENTATION
Neonates:
- Micropenis
- Hypoglycaemia
- Severe jaundice
Infants and older children:
- poor growth, severely slowing from age 2-3
- SHort stature
- Slow development of movement and strength
- Delayed puberty
Growth hormone stimulation test
Measuring response to medications that normally stimulate the release of GH (e.g. glucagon, insulin, arginine, clonidine)
GH levels monitored for 2-4 hours after administering medication to assess hormonal response
Growth hormone deficiency: investigations
Growth hormone stimulation test
Test for other associated hormone deficiencies (e.g. thyroid, adrenal deficiency)
MRI brain
Genetic testing (associated genetic conditions e.g. turners syndrome, Prader-Willi syndrome)
X-ray or DEXA scan to determine bone age and help predict final height
Growth hormone deficiency: TREATMENT
Daily subcutaneous injections of GROWTH HORMONE (SOMATROPIN)
Treatment of other associated hormone deficiencies
Close monitoring of height and development
Prevalence of congential hypothyroidism
1 in 3000 newborns
Common cause of Congenital hypothyroidism
Underdevelopment of thyroid gland (dysgenesis)
Fully developed gland that doesn’t produce enough hormones (dyshormonogenesis)
Rarely a problem with the pituitary or hypothalamus
Congenital hypothyroidism: presentation
Often picked up on NEWBORN BLOOD SPOT SCREENING TEST
- prolonged neonatal jaundice
- poor feeding
- constipation
- increased sleeping
- reduced activity
- slow growth and development
Acquired hypothyroidism: causes
Autoimmune thyroiditis (hasimotos thyroiditis)
Hashimoto’s Thyroiditis: Antibody associations
Anti thyroid peroxidase (anti-TPO) and anti-thyroglobulin antibodies
Hypothyroidism: Management
LEVOTHYROXINE
Fully thyroid function test - TSH, T4, T3
Thyroid system