Endocrine - investigations and treatments Flashcards
main antibody in graves
anti-TSH
symptomatic control of hyperthyroid
propranolol
main treatment of hyperthyroid
carbimazole
main risk of carbimazole use
agranulocytosis
tx hyperthyroid in 1st trimester of pregnancy
propylthiouracil
tx hyperthyroid in 2nd and 3rd trimester pregnancy
carbimazole
usual regime of carbimazole
started at 40mg then reduced gradually, continued for 12-18 months
tx thyroid storm
Iv propranolol
IV dexamethasone
carbimazole or PTU
antibody in hashimotos
anti-TPO
anti-Tg
tx hypothyroidism
levothyroxine
young - 50-100mcg
older - 25-50mcg
when should thyroid hormones be checked following a change in thyroxine
after 8-12 weeks
how much should levothyroxine be increased in pregnancy
by 25-50 mcg
advice for patient if taking levothyroxine with iron or calcium
take at least 4 hours apart
levothyroxine must also be taken 30 mins before food
tx myxoedema coma
IV levothyroxine
IV fluids
IV steroids (due to possibility of co-existing adrenal insufficiency)
TSH and T4 seen in
primary hyperthyroidism
high T4
low TSH
TSH and T4 seen in
secondary hyperthyroidism
high T4
high TSH
TSH and T4 seen in
subacute hyperthyroidism
low TSH
normal T4
scintigraphy uptake seen in toxic adenoma
single nodule of high uptake
scintigraphy uptake seen in de quervians
globally reduced uptake
scintigraphy uptake seen in graves
diffuse increased uptake
scintigraphy uptake seen in toxic multinodular
high patchy uptake in multiple locations
phases of de quervians
phase 1 - hyperthyroid- 3-6 weeks
phase 2 euthyroid 1-3 weeks
phase 3 hypothyroid (weeks - months)
phase 4 normal
tx de quervians
self limiting
NSAID if painful goiture
TSH and T4 in primary hypothyroid
t4 low
tsh high
TSH and T4 in secondary hypothyroid
low TSH
low t4
TSH and T4 in subclinical hypothyroid
normal T4
high TSH
TSH and T4 in sick euthyroid
low TSH
low T4
TSH and T4 in poor compliance with thyroxine
high TSH
high T4
phases of post-partum thyroiditis
thyrotoxicosis
hypothyroid
normal
treatment of post-partum thyroiditis
thyrotixic phase- propranolol
hypothyroid phase - thyroxine
gold standard investigation for thyroid cancer
US guided FNA
tx thyroid cancer
thyroidectomy + radio-ablation
tx thyroid cancer if low risk, < 50 < 4cm
lobectomy
what monitoring is required in thyroid cancer
yearly thyroglobulin
grading of thyroid cancer from USS
U2 - benign
U3 - atypical
U4 - probably malignant
U5 - malignant
grading of thyroid cancer from FNA
Thy1 - inadequate Thy2 - benign Thy3 - atypical Thy 4 - probably malignant Thy 5 - malignant
dx of osteoporosis
DEXA scan < -2.5
DEXA scan osteopenia
-1 to -2.5
normal BMD on DEXA
above -1
1st line tx osteoporosis
bisphosphonates - alendronate, risedronate
when are bisphosphonates taken
once a week with large glass of water and sitting up for at least 30 minutes
tx osteoporosis if cant tolerate bisphosphonates
if cant tolerate alendronate due to GI symptoms try another bisphosphonate
if cant tolerate any bisphosphonates - strontium ranelate
tx osteoporosis if no response to bisphosphonate or strontium
SC teriparatide
as well as bisphosphonates what should osteoporosis management include
vitamin D and calcium supplements
bloods of pagets disease of the bone
ALP, ca, phos
increase ALP
normal calcium and phosphate
tx pagets
analgesia
bisphosphonates
lack of vitamin D leads to what bone problem in
- children
- adults
rickets
osteomalacia
pathophysiology in renal bone disease
damaged kidneys excrete less phosphate –> hyperphosphataemia and hypocalcaemia
reduced vit D activation by kidneys also leads to hypocalcaemia
hypocalcaemia leads to secondary hyperparathyroidism –> high PTH
bloods of osteomalacia caused by vitamin D deficiecny
hypocalcaemia hypophosphataemia low vitamin D high ALP high PTH
blood of osteomalacia caused by renal bone disease
hypocalcaemia
hyperphosphataemia
high ALP
high PTH
differentiating feature of osteomalacia caused by RBD and low vit D
RBD - high phosphate
vit D deficiency - low phosphate
tx osteomalacia cause by vitamin D deficiency
calcium / Vitamin D supplements- calcium D3
1st line treatment osteomalacia by RBD
reduce dietary intake of phosphate
2nd line treatment of osteomalacia by RBD
phosphate binders - sevelamer
vitamin D - alfacalcidol, calcitrol
ix primary hyperparathyroidism
24 hour urinary calcium - high
bloods of primary hyperparathyroidism
PTH raised or inappropriately normal (should be low given high Ca)
hypercalcaemia
hypophosphataemia
definitive tx primary hyperparathyroidism
total parathyroidectomy
not definitive - but watchful waiting if no evidence of organ damage/Ca not too high
tx primary hyperparathyroidism if not suitable for surgery
cinacalcet ( calcium mimetic)
bloods of secondary hyperparathyroidism
low Ca
high PTH
high phosphate
normal response of parathyroid gland to low calcium
bloods of tertiary hyperparathyroidism
high calcium
high PTH
prolonged hypocalcaemia leads to parathyroid hyperplasia
what cancers can release PTHrp
squamous cell lung
renal
breast
bloods of paraneoplastic PTHrp
high Ca
low PTH
bloods of primary hypoparathyroidism
low ca
low PTH
high Phosphate
tx primary hypoparathyroidism
alfacalcidol
bloods of pseudo-hypoparathyroidism
low Ca
high phosphate
high PTH
dx of hypoparathyroidism
measure urinary cAMP and phosphate after infusion of PTH
primary hypoparathyroidism - increase in both
pseudo type 1 - neither increases
pseudo type 2 - only cAMP rises
what is pseudo pseudo hypoparathyroidism
morphological features of pseudo hypoparathyroidism but bloods normal
tx pseudo and pseudopseudo hypoparathyroidism
calcium and vit D supplemetns
ix of familial hypocalciuric hypercalcaemia
urine calcium:creatinine clearance ratio
tx acute hypercalcaemia
IV fluids - normal saline following rehydration IV bisphosphonates calcitonin - quicker than bisphos steroids loop diuretics
tx hypocalcaemia acute
IV calcium gluconate 10ml 10% over 10 minutes
tx hypocalcacemia mild
calcium and vit D supplements
features of MEN 1
parathyroid hyperplasia
pituitary adenoma
pancreatic tumour
features of MEN 2a
medullary thyroid carcinoma
phaeochromocytoma
parathyroid hyperplasia
features of MEN 2b
medullary thyroid carcinoma
phaeochromocytoma
neuromas
marfanoid appearance
ix hypopituitarism
measure all pituitary hormones
insulin tolerance/stress test (gold standard)
- if CI e.g. IHD or epilepsy, can do glucagon stimulation test
test for ACTH deficiency
short synacthen test
imaging in pituitary disease
MRI
what does craniopharyngioma usually cause hormone wise
diabetes insipidus
1st line tx hyperprolactinaemia
cabergoline, bromocriptine
2nd line treatment hyperprolactinaemia
surgical excision if no success with medical treatment
1st line ix for acromegaly
serum IGF-1 levels
gold standard in confirming acromegaly
glucose tolerance test
1st line treatment acromegaly
transphenoidal surgery
2nd line treatment acromegaly
octreatide, sandostatin
or pegvisomant - doesnt shrink tumour, still need surgery if mass effect, once SC administration
1st line ix of DI
plasma and urine osmolalities
urine osmolality > 700 excludes DI
osmolality of Diabetes insipidus
low urine osmolality
high serum osmolality
peeing out all water
gold standard investigation for DI
water deprivation test
how do you differentiate nephrogenic and central DI
after water deprivation give ADH
- nephrogenic - no rise in urine osmolality
- central - rise in urine osmolality
tx central DI
desmopressin
tx nephrogenic DI
thiazide diuretic
sodium potassium and glucose levels in Addisons
low sodium
high K
low glucose
diagnostic test for addisons
short synacthen test
results of short synacthen test in addisons
no rise in cortisol after giving synthetic ACTH
test for addisons if short synacthen test not available
9am cortisol level - will be low
tx addisons
fludrocortison + hydrocortisone
how is addisons treatment given
divided dose, in first part of day
what should patients be told about their steroid doses in sickness
double hydrocortisone for a week
fludrocortisone stays same
if vomiting replace with IM
tx addisonian crisis
fluid resus - saline or dextrose if hypoglycaemia
IV hydrocortisone STAT
what acid base problem dose addisons causes
hyperkalaemic metabolic acidosis
aldosterone
cortisol
androgen
levels in addisons vs bilateral adrenal hyperplasia
addisons - all low
bilateral adrenal hyperplasia - increased androgen, reduced aldosterone, reduced cortisol
addison features but no hyperpigmentation think…
secondary adrenal insufficency e.g. pituitary or LT steroid - no build up of ACTH
1st line ix for hyperaldosteronism (primary = conns)
plasma aldosterone:renin ratio (high)
sodium and potassium in hyperaldosteronism
high sodium
low potassium
ix of hyperaldosteronism if confirmed with plasma aldosteronism:renin ratio
CT abdomen and adrenal vein sampling
saline suppression test results of aldosteronism
failure to suppress aldosterone by 50% following consumption of water
tx hyperaldosteronism
spironolactone
tx conns
spironolactone
removal of adenoma
ix of cushings if pituitary problem
MRI
ix of cushings if adrenal problem
CT
what acid base problem does cushing cause
hypokalaemic metabolic alkalosis
+ hyperglycaemia
1st line ix to confirm cushings
overnight dexamethasone suppression test
1st line ix to localise cushings
plasma ACTH and cortisol at 9am and midnight
results of plasma ACTH and cortisol at 9am and midnight in ACTH dependent cause
elevated ACTH and cortisol
results of plasma ACTH and cortisol at 9am and midnight in ACTH independent cause
undetectable ACTH with raised cortisol
example of ACTH independent causes of cushings
adrenal adenoma / carcinoma
steroids
examples of ACTH dependent causes of cushings
pituitary adenoma
ectopic from small celll lung cancer
diagnostic test for cushings
48 hour high dose dexamethasone suppression test
results of 48 hour high dose dexamethasone suppression test in cushings disease i.e. pituitary adenoma
cortisol suppressed
ACTH suppressed
results of 48 hour high dose dexamethasone suppression test in ACTH independent cause i.e. adrenal adenoma
cortisol not suppressed
ACTH suppressed
results of 48 hour high dose dexamethasone suppression test in ectopic ACTH
neither cortisol or ACTH suppressed
ix if ectopic cause
CT CAP
tx of cushings disease
trans sphenoidal surgical excision of pituitary adenoma
tx cushings by adrenal adenoma
adrenectomy
ix pheochromocytoma
- 1st line and type of scan
24 hour urine metanephrines
MIBG scan
tx phaeochromocytome
alpha blockade - phenoxybenzamine
then beta blockade - propanolol
then
surgical excision of tumour
tx hypertensive crisis in phaeochromocytoma
labetolol
