General Medicine: Endocrine (excl diabetes) Flashcards
Outline the basic pathway of thyroid hormone production
(Ant pituitary) –> TSH –> (thyroid) –> T3/4
How do hypo and hyperthyroidism compare with
Systemic symptoms
Cardiac
Skin
Gastrointestinal
Gynaecological
Neurological
Hypothyroidism // hyperthyroidism
weight gain, lethargy, cold intolerance // weight loss, restless, heat intolerance
none // palpitations
Dry, non hairy, non-pitting oedema // sweaty, bubbly tibia
constipation // diarrhoea
reduced reflex, carpal tunnel // tremor
Interpret the following
TSH: Low
T4: High
What are the causes of the following
Thyrotoxicosis
Causes
- Graves (60%)
- Toxic multinodular goitre
- Acute subacute thryoiditis/ acute hashimoto’s (before it goes hypo)
- Amiodarone therapy
In addition to TFTs, what clinical and lab tests would point towards
Grave’s disease
Toxic multinodular goitre
Grave’s
Clinical: big and palsied eyes, pre-tibial myxoedema, digital clubbing
Labs: anti-TSHR, anti-TPO, diffuse homogenous intake of radio-iodine
TMN
Nuclear scintigraphy reveals patchy uptake
Interpret the following TFT results
T4 // TSH
low, high
low, low
normal, high
Hashimoto’s
2ary cause, sick euthyroid
subclinical, poor compliance
How do you treat thyrotoxicosis?
Propranolol for tremor
Carbimazole to block T4 production
Radioiodine/surgery to remove if persistent
What is the treatment for hypothyroidism?
levothyroxine
How do you check if levothyroxine treatment is working/being complied with?
Check TSH in normal range
TSH high because low T4 so therapy should cause negative feedback
How does thryoid storm and myoedema coma compare in terms of
Hx
Presentation
TS // MC
Overactive thyroid // underactive
Confusion, fever, N+V (+/-jaundice) // Confusion and hypothermia
How do you manage myoxedema coma?
IV thyroxine
IV fluids
IV corticosteroids while adrenal insufficiency ruled out
How do you treat thyroid storm?
IV propranolol
Methimazole, PTU
Dexamethasone to reduce conversion
How can thyroid cancer be distinguished from other thyroid lumps
Lacks the features of hyper/hypothyroidism
What investigations are performed in suspected thyroid cancer?
1st line: Ultrasound
GS: Fine needle aspiration
‘mixture of papillary and colloidal filled follicles, tumour has papillary projections and pale empty nuclei’
Which thyroid cancer is this and how does it spread?
Papillary
Lymph node spread
‘encaspulated tumour with microscopic capsular invasion’
What thyroid cancer is this and how does it spread?
Follicular carcinoma
Vascular invasion predominates
How are papillary and follicular thyroid cancers treated?
Thyroidectomy + radioiodine 131 to kill residue cells
Yearly thyroglobulin levels
What endocrine disorders give you a high BP and outline their distinguishing characteristics
Hyperaldosteronism: hypokalaemia (muscle wasting), alkalosis
Phaeochromocytoma: intermittent headaches, palps, sweating, anxiety
Cushing’s syndrome: moon face, pigmented skin
Congenital adrenal hyperplasia: female virilisation
Acromegaly: Big head, hands and feet, headaches, bitemporal hemianopia, sweaty
Bronzed skin, thin, fatigue and salt craving indicates which endocrine disorder
Addison’s disease
What do the following aldosterone renin ratios suggest
high/high
high/low
2ary (renal artery stenosis)
1ary: Conn’s syndrome
If primary hyperaldosteronism is suspected from A:R testing, what further test should be performed?
Adrenal CT to visualise adeomas
if -ve adrenal venous sampling for unilateral adenoma vs bilateral hyperplasia
What is the most common cause of hyperaldosteronism?
Renal artery stenosis
chonic underperfusion of kidney leads to increased aldosterone production
How do you manage renal artery stenosis?
Antihypertensives, statin + antiplatelets
Stenting of renal artery
How do you manage primary hyperaldosteronism?
unilateral adenoma: surgery
Bilateral hyperplasia: spironolactone
How would you investigate and treat a patient with addison’s?
1st: 9am cortisol = 100-500
GS: short synACTHen test, cortisol does not double
+ APS 1/2 autoantibodies
+ CT for adrenals, MRI for pituitary
What is the management of Addison’s disease?
Hydrocortison 2-3 daily for cortisol
fludrocortisone for aldosterone
If someone with addison’s is ill what should they do regarding their meds
Double hydrocortisone
Keep fludrocortisone the same
Addison’s patient very unwell post-op; their notes show they have not received their hydrocortisone, what is the diagnosis and management?
Addisonian crisis
IV hydrocortisone 100mg
1 litre saline over 30-60 mins
6hrly hydrocortisone until stable. No fludrocortisone
Oral replacement after 24hrs, reduce to maintenance over 304 days
How do you investigate cushing’s syndrome to
confirm the syndrome
reveal the cause
Diagnosis
low dose dexamethasone: undampened cortisol confirms syndrome
high dose dexamethasone:
no suppression: ectopic ACTH
ACTH: Adrenal adenoma
ACTH +cortisol : pituitary (Cushing’s disease)
*dexamethesone dampens ACTH
How do you treat cushing’s syndrome?
Surgical removal of source
Where not possible, remove adrenals and replace steroid hormones for life
What investigation result confirms phaeochromocytoma?
24 hr urinary metanephrines will be raised
+ cathecolamines but these are less reliable
What is the management of phaeochromocytoma?
- Alpha blockers
- Add beta blockers
Def: adrenalectomy
What are the investigation findings in acromegaly?
- IGF-1 levels raised
- OGTT to confirm if raised; shows no impairment of GH
+ pituitary MRI to look for tumour
What is the treatment of acromegaly?
1st line: TS surgery
unresectable:
- Octreotide (Somatostatin analogue) to inhibit GH
- Pegvisomant (GHR antagonist) but doesnt shirnk size
- Bromocriptine (dopamine agonist) to compete with GH
Bones, stones, abdo groans and psychic moans refers to what endocrine disorder?
Hyperparathyroidism
Bones: Pain, fractures due to calcium release
Stones: Renal stones due to increaesd calcium
Abdominal groans: pancreatitis, constipation + ulcers due to increased calcium
Psychic moans: anxiety, depression
What do the following PTH and Ca2+ readings show
PTH, Ca2+
high, high
high, low/normal
Primary (PTH tumour) tertiary (hyperplasia following 2ary)
secondary (vit D, CKD)
What is the treatment for hyperparathyroidism?
1ary, 3ary: surgery
2ary: Correct vit D, CKD
What are the clinical features of hypoparathyroidism?
Muscle aches
Depression
Cataracts
+ Prolonged QT
How do the following differ from hypoparathyroidism?
Pseudohypoparathyroidism
Pseudopseudohypoparathyroidism
HPT
Impaired stimulation/synthesis of calcium release
BOTH urinary cAMP + phosphate high after PTH infusion
PSEUDO
Imparired G protein causing calcium insensitivity to PTH
Assoc: low IQ, short height and 4th/5th fingers
ONLY ONE/NEITHER of cAMP+phosphate high after PTH infusion
PSEUDOPSEUDO
Above phenotype but normal biochemistry
Since PCOS and POF mess with periods and fertility how can you tell them apart by
Symptoms
FSH/LH
Oestrogen
Testosterone
PCOS // POF
Hairy // Night sweats, vaginal dryness
High // high
Normal // low
High // normal
How do you treat PCOS
COC/Co-pyprindol/elflornithine for acne
Clomifene, metformin for infertility
How do you treat POF?
HRT
COC pill if <50yrs as reduces breast cancer and VTE risk
Outline the main steroids from most to least glucocorticoid activity (reverse direction for mineralocorticoid)
Dexamethasone/betamethasone
Prednisilone
Hydrocortisone
Fludrocortisone
What is the effect of corticosteroids on
Glucose levels
Immune cells
Physical appearance
Mental health
high glucose due to impaired insulin function
High neutrophils, low others
Cushingoid features
psychosis, depression, insomnia
What are the side effects of mineralocorticoids
Fluid retention, hypertension
Who should have gradual withdrawal of corticosteroids?
>=40mg daily for over a week
Received more than 3 weeks treatment
Repeat courses
