Endocrinology Flashcards
Features/signs to ask about in thyroid history
Heat/cold intolerance
Goitre/neck swelling
If yes ask about swallowing and breathing problems
Tremor
Palpitations
Weight and hunger
Lethargy
Sleep
Eye problems
Bowel habitInvestigation of adrenal insuffiency i.e. ? Addisons
9am cortisol and SST U&Es (high K, low Na) Calcium (mildly elevated) Glucose (may be low) TFTs (raised TSH with normal T4) Plasma renin ( increased due to mineralocorticoid deficiency FBC (anaemia of chronic disease) Adrenal antibodies (+ve in 80%) CT Ferritin (? Haemochromatosis) HIV test Lupus anticoagulant
Investigation of hypo pituitarism
TSH and free T4 Testosterone, LH and FSH Prolactin Cortisol, ACTH, short synacthen test Insulin like growth factor 1 Urine osmolality ( low in DI)
Differential diagnosis for pituitary failure
Trauma/SAH
Tumour
Infiltration (sarcoidosis, haemochromatosis, lymphoma)
Infection e.g. TB or abscess
Kill and syndrome
Sheehans syndrome
Cranial radiotherapy especially in childhood
Signs of Cushing’s?
Proximal myopathy High glucose Thin skin, easy bruising Moon face Supra scapular fat pad Osteoporosis/fractures Weight loss (more a feature of ectopic Cushing's) Pigmented skin if Cushing's disease due to ACTH secreting pituitary adenoma
Investigations for Cushing’s
Midnight cortisol Overnight Dexamethasone supression test. High dose and low dose ACTH MRI pituitary, CT adrenals, CT chest
Investigation for acromegaly
Insulin like growth factor (IGF1 ) Oral glucose tolerance test MRI pituitary BP Diabetes test CXR (?cardiomegay) ECG
Investigation for diabetes insipidus
Remember DI is lack of vasopressin release or insensitivity to vasopressin on the kidney
Water deprivation test (test urine and serum osmolalities at regular intervals - they won’t increase with DI) follow this by IM desmoppression. If levels normalise then you know it is cranial DI.
Investigation for Conns:
Plasma aldosterone to plasma renin ratio
U&Es
Bicarbonate
(Hypokalaemic alkalosis is cause of Conn’s)
Questions to ask if hypo pituitarism suspected (clue : think of all the hormones)
TSH: Heat/cold, weight change, skin and visual change, lethargy, bowel change.
Prolactin/FSH/LH: libido, amenorrhoea, infertility, gallactorrhoea, reduced shaving in men, gynaecomastica
ACTH: hyper pigmentation, weight loss, low BP
GH: short stature, lethargy
ADH (posterior pituitary release): polydipsia, thirst
Then ask about symptoms related to cause: drugs, head injury, headache, visual changes
Causes of hyperprolactinaemia
Prolactinoma (most are micro <10mm, 10% macro)
Head injury (damages pituitary stalk so dopamine cannot negatively feedback to switch off prolactin)
Dopamine antagonists e.g. Antipsychotics
Lactating
Post seizure
Tumour preventing dopamine release
Posterior pituitary hormones
Oxytocin and ADH
Treatment of prolactinoma
No treatment needed if asymptomatic
Cabergoline (or 2nd line bromocriptine) this works by being a dopamine agonist causing prolactin release switch off by negative feedback
Surgery usually transphenoidal
Signs of acromegaly
Large hands Coarse skin Sweating (indicates active disease) Prominent supra orbital ridge Prognathism Widely spaced teeth Macroglosssia Acanthosis nigricans
Complications of acromegaly
Hypertension (indicates active disease) Carpal tunnel syndrome Diabetes Bitemporal hemianopia Goitre GI malignancy Heart failure Arthropathy Proximal myopathy Obstructive sleep apnea (50%)
