Endo 2 Flashcards
What are causes of low Mg
LOW INTAKE: TPN, alcoholic, malnutrition
RENAL LOSS: diuretics (loop, thiazide), metabolic disorders (Gitelman, Bartter), nephrotoxic drugs (amphotericin B, aminoglyocosides)
GI LOSS: diarrhoea
what metabolic abnormalities does hypomagnaesemia often occur with
low potassium
low calcium
when must you suspect hypomagnaesemia
when the patient has:
- refractory hypokalaemia
- unexplained hypocalcaemia
sx hypomagnaesemia
nausea, anorexia, voomiting
parasthhesia
seizures
tetany
arrythmias
how do you manage hypomagnaesemia
> 0.4: magnesium salts, orally
<0.4: IV MgSO4 40mmol /24h
what causes acromegaly
a pituitary adenoma producing excess GH
sx of acromegaly
headachhes
soft tissue swelling (enlarged hands and feet)
prognathism (protruding jaw)
macrocossia
cx: HTN, DM
ix of acromegaly
IGF1 raised
OGTT > GH raised
what is normal calcium rnage
2.2 to 2.6
what causes release of PTH
low dietary calcium or low sunlight > cause low serum calcium
functions of PTH
increase bone calcium resoprtion
increease renal calcium resorption
produce 1alpha hydroxylae > hydroxylase vitamin D > increase calcium resorpion in intestineb
what does PTH do to phosphate
gets rid of it (PHOSPHATE TRASHING HORMONE)
what are the roles of activated vit D
increase intestinal calcium absorption
increase intestinal phosphate absorption
bone formation
summarise osteomalacia in one sentence
normal bone density
but ABNORMAL bone structure (demineralised bone)
what is the principal cause of osteomalacia
Vit D deficiency
what are RF / co-morbidities that lead to osteomalacia
RF: dark skin, lack of sunlight, dietary deficiency, malabsorption
Co-morb:
- renal failure (as the vit D is not hydroxylased)
- anticonvulsants (break down vit D)
- chapati (reduce absorption)
what is osteomalaxia in children called
rickets
sx of osteomalacia
bone and muslce pain
increased fracture risk
sx of rickets
bowel leg s
costochondral swelling
myopathy
widened epiphysis at wrist
looser zones on x r
explain what happens to hormones and electrolytes in osteomalacia (starting from the low vit D)
low vit D > less calcium absorbed > raised PTH > raised bone resorption (so raised ALP) > normal/ low calcium with BRITTLE bone
what is bone like in osteomalacia
weak and demineralised
what kind of hyperparathyroidism occurs in osteomalacia
SECONDARY hyperparathyroidism
summarise osteoporosis in one sentence
low bone density
normal bone structure
what is osteoporosis due to
- age related decline
- endocrine (cushiing’s, hyperthyroid, early menopause)
- lifestyle (smoking, alcohol, anorexia)
sx of osteoporosis
asymptomatic
until pathological fracture occurs
how do you ix osteoporosis
normal calcium and phosphate
DEXA Scan ( T score
what does a T score between -2.5 and -1 indicate
osteopoenia
how do you manage osteoporosis
lifestyle: stop smoking, reduce alcohol, weight bearing exercise
medical: vit D / calcium
- biphosphonate ss
- teriparatide
- strontium
- HRT
- Raloxifen
what first question must you ask when you see a HIGH calcium
is PTH HIGH or LOW
Causes of HIGH calcium, HIGH PTH
This is INAPPROPRIATE: primary hyperparathyroidism
- Parathyroid adenoma
- Parathyroid hyperplasia
- Parathyroid carcinoma
what are electrolytes like in primary hyperparathhyroidism
high calcium
high PTH
low phosphate
causes of HIGH calcium, LOW PTH
Malignancy (SCLS, bony mets, myeloma)
Other (sarcoid, thyrotox, addisons, thiazide)
how do you treat hypercalcaemia
Fluids (+ biphosphonates if cancer)
causes of LOW CA, HIGH PTH
vit D deficiency
CKD
PTH resisztance
cuases of LOW CA, LOW PTH
surgical (post thyroidectomy)
autoimmune
how do you trreat low calcium
calcium + vit D supplements
if Ca <1.9: calcium gluconate
mx of primary hyperparathyroidism (hihg calciumn, high PTH due to parathyroid growth)
TOTAL PARATHYROIDECTOMY
Cinacalcet (may be prescribed if not suitable for surgery - mimics the action of calcium on tissue, reducing PTH)
explain the negative effects of CKD on calcium and phosphatye
Kidneys usually allow activation of vit D > CKD causes low calcium
Kidneys usually excrete PO > CKD causes excess PO
how do you manage low calcium, high phosphate in CKD
- Reduce dietary PO
- Use phosphate binders (e.g. aluminium based binder, sevelamar)
- Vit D supplement (alfacalcidiol, calcitrio)
- consider parathyroidectomy
what is the MAIN CAUSE of primary hyperaldosteronism
- BILATERAL ADRENAL HYPERPLASIAA (up to 70% of cases)
what are the two causes of primary hyperaldosteronism
- bilat adrenal hyperplasia
- adrenal adenoma (Conn’s)
How do you distinguish between bilat adrenal hyperplasia and adrenal adenoma (Conn’s)
HR-CT abdo and adrenal vein sampling
how do you manage a bilat adrenal hyperplasia
aldosterone antagonist (e.g. spironolactone)
how do you manage an adrenal adenoma in Conns
surgery (removes the tumour but leaves some adrenal gland, so the patient does not become addisonian)
when must levothyroxine be given if co-administered with iron / calcium supplements
at least 4 hours before or after
how do you manage hypothyroidism in pregnancy
increase dose by up to 50% in first 4-6 weeks of pregnancy
how do you give hydrocortisone in addisons
twice daily
the largesst dose in the morning, second dose after lunch
how many units (of insulin) ae there in 1ml
100
what do glucocortcoids do to WBC and neutrophil count?
WBC decreases
but neutrophils increase initially
whaat is the MOA of MODY
Autosomal DOMINANT
how do you manage thyroid cancer
THYROIDECTOMY (hemi or total) + IODINE 131 (to kill all remaining cells)
yearly followup > if positive, administer more I-131
when can you discharge someone with thyroid cance r
if in remission for 7 years
what is the effect of heparins on potassium
increase potassium
as they inhibit aldosterone
what is the effect of tacrolimus on potassium
reduce K+ excretion> increase potassium
what is the effect of NSAIDS on the kidney
they inhibit reniin release
HYPERKALAEMIA on ECG
tall tented T wave
Broad QRS
flat P wave
Prolonged PRR interval
Sine wave > cardiac arrest
do pituitary adenomas always have to secrete hormones?
NO - they could be NON FUNCTING PITUITARY ADENOMAS
they would present with hypopituitarism and pressure effects
what kind of breathing occurs in DKA
KUSSMAUL breathing - excess CO2 is exhaled to try to compensate for metabolic acidosis
what diabetics need to be followed up by the local foot centre
ALL DIABETICS who have any foot condition other than CALLUSES
what is thyroid acropatchy
TRIAD OF
- nail clubbing
- tissue swelling of the hands and feet
- new bone formation
what is Nelsons syndrome
removal of the adrenal glands > pituitary enlargement > hypopituitarism from compressing the stalk and RAISED ACTH (hyperpigmentation)
What test can help distinguish between T1DM and T2DM
C peptide – will be LOW in T1 (because low insulin production) but RAISED in T2 (due to high insulin production, but insensitivity of cells)
how does HYPOThyroidism affect periods
HYPOthyroidism causes MENORRHAGIA
How does HYPERthyroidism affect perodos
causes AMENORRHHOEA
HbA1c target for T1 DM
48
