Endocrinology Flashcards
What are the microvascular comps of DM?
Retinopathy
Nephropathy
Neuropathy
Define Mody
Rare autosomal dominant form of type 2 DM that affects the young
What fasting glucose level is dx of diabetes?
> 7
When is HbA1c not a useful measure?
pregnancy
haemoglobinopathies
children
What random plasma glucose is dx of diabetes?
11.1
What tx can ophthalmology do to try and prevent progression of diabetic retinopathy?
Laser therapy
Which autoantibodies are raised in type 1 DM?
Anti-GAD
Islet cell Abs
Which test can hep differentiate type 1 DM from type 2?
C peptide
At what HbA1c level would you start a patient on a second diabetic drug?
58
What example drug would you commence if metformin alone has failed to tx dm?
Sulphonylurea (e.g. gliclazide)
What is the main side effect of metformin?
GI upset (lactic acidosis if low GFR)
What is a key benefit of using metformin?
Doesn’t cause hypoglycaemia
What is the triad of symptoms present in HHS?
Hypovolaemia
Marked hyperglycaemia (>30)
Osmolality >320
How does HHS px/
Extreme dehydration with altered mental state
What is the tx for HHS?
Rehydrate slowly with 0.9% saline over 48 hrs
only use insulin if glucose not falling with fluids
What can precipitate HHS/
Infection MI Dehydration Diuretics Poor control
Which features make up metabolic syndrome?
Truncal obesity Hypertension reduced HDLs High triglycerides Pre-diabetes
Which diseases is metabolic syndrome associated with?
T2DM
NAFLD
PCOS
CVD
What BMI would class you as underweight?
Less than 18.5
Which medications commonly cause obesity?
Corticosteroids Antidepresssants (esp mirtazapine) Sulphonylurea lithium Beta blockers
Which drug can help tx obesity?
Orlistat (lipase inhibitor)
Which conditions does untreated hypothyroidism predispose you to?
Heart disease
Dementia
Which drugs most commonly cause hypothyroidism?
Lithium
Amiodarone
Name some causes of hypothyroidism
Atrophic hypothyroidism Hashimotos thyroiditis Postpartum thyroiditis Drugs Iodine deficiency Thyroidectomy
What’s the most common cause of hypothyroidism in the UK?
Atrophic hypothyroidism (no goitre)
What risks are associated with overmedication of levothyroxine?
Osteoporosis
arrhythmia (AF)
What are the causes of hyperthyroidism?
Grave’s disease
Toxic adenoma
Toxic multinodular goitre
De Quervains
Which antibodies are positive in graves?
Anti-TSH receptor Abs
Signs of thyroid eye disease
Lid lag Lid retraction Opthalmoplegia Exophtalmus diplopia
Which two drugs are used in the long term mx of hyperthyroidism?
Carbimazole
Propylthiouracil
What is the main side effect associated with carbimazole?
Agranulocytosis leading to neutropaenic sepsis
What are the comps associated with hyperthyroidism?
HF Angina AF Osteoporosis Gynaecomastia Thyroid storm
What is first line tx for thyroid storm?
propranolol IV
Which drugs would you give after propranolol to tx thyroid storm?
Carbimazole PO
Lugols solution
IV hydrocortisone
What is the most common cause of thyroid cancer?
Papillary carcinoma
Which drugs commonly cause hypercalcaemia?
THIAZIDES
LITHIUM
Which causes of hypercalcaemia cause a raised ALP?
Bone metastases
Sarcoidosis
Thyrotoxicosis
Lithium
What does high calcium and low phosphate typically suggest?
Primary hyperparathyroidism
What would causes hypercalcaemia with raised/normal phosphate and normal ALP?
Myeloma
Vit D excess
Sarcoidosis
Which malignancies most commonly metastasise to bone?
Breast, kidney, bronchus, thyroid, prostate
What is the definitive tx for primary hyperparathyroidism?
Surgery
What conservative measure would you suggest to patient with mild primary hyperparathyroidism to prevent formation of renal stones?
Overhydration
What tx would protect BMD in primary hyperparathyroidism?
bisphosphonates
What is tx for acute severe hypercalcaemia?
Rehydrate (4-6l saline over 24 hours)
IV bisphosphonates
What biochemical abnormalities would suggest secondary hyperparathyroidism?
High PTH, low calcium, high phosphate, low vit D
How can you treat secondary hyperparathyroidism due to CKD?
Calcitriol
Gut phosphate binders
What are the causes of hypocalcaemia?
CKD Hypoparathyroidism (e.g. post-surgery) Vit D deficiency!! Drugs acute pancreatitis
What are the sx of hypocalcaemia?
Cramps Perioral numbness Carpopedal spasm (trousseaus sign) Convulsions psychosis
What is chvosteks sign?
Tapping of facial nerve causes ipsilateral twitching of facial muscles (seen in hypocalcaemia)
How do you adjust calcium for albumin level?
+0.1 for every 4g/L albumin is below 40
-0.1 for every 4g/L albumin is above 40
Why do you need to adjust calcium for albumin level?
Only unbound albumin is physiologically important
Which hormone do pituitary adenomas most commonly produce in ranking order/
Prolactin > GH > ACTH > TSH > LH/FSH
What are the local effects of a pituitary adenoma?
Headache
Visual field defects
How does a craniopharyngioma px?
Headache
Visual field defect
Hypopituitarism
What is the drug tx for prolactinoma?
Bromocriptine or cabergoline
What are the three main causes of raised prolactin?
Prolactinoma
Pregnancy/puerperium
Antipsychotics
How does prolactinoma px in men?
Erectile dysfunction and loss of libido
+- mass effect
Which two conditions does acromegaly increase the risk of?
T2DM
colon cancer
What are the symptoms of acromegaly?
Acroparaesthesia Amennorhoea Decreased libido Headache Increased sweating Snoring Arthralgia back ache
What are the signs of acromegaly?
Increased growth of hands
Macroglossia
Acanthosis nigricans
carpel tunnel syndrome
How is acromegaly diagnosed?
OGTT (measure GH)
Serum IGF-1
Why is a random GH test poorly diagnostic for acromegaly?
Secretion is pulsatile
How is acromegaly treated?
1) Transphenoidal surgery
2) Somatostatin analogues (e.g. octreotide) +- radiotherapy
What are the causes of cushings syndrome?
Iatrogenic (steroids)
Adrenal adenoma
Cushings disease Ectopic ACTH (e.g. Small cell lung Ca)
What are the first line tests for cushings syndrome?
Overnight dexamethasone suppression test or 24h urinary free cortisol
Which antibodies are raised in autoimmune Addisons disease?
21-hydroxylase autoantibodies
What electrolyte abnormalities are seen in Addisons disease?
Low sodium
Raised potassium (memory tool = add k up, k conns down)
Low glucose
What test is diagnostic for Addisons disease?
Synacthen test (short ACTH stimulation test)
Which conditions is addisons associated with?
vitiligo
T1DM
pernicious anaemia
thyroid disorders
How do you manage Addisonian crisis?
Bloods for cortisol and ACTH
U & Es (for sodium and potassium)
IV HYDROCORTISONE STAT
What are the features of conn’s syndrome?
Oedema (water and Na retention)
HTN
Hypokalaemia (weakness, cramps, paraesthesia)
What are the causes of secondary hyperaldosteronism?
Reduced renal perfusion: renal artery stenosis diuretics CCF accelerated hypertension
What are the Ix for hyperaldosteronism?
U & E
BP
ALDOSTERONE:RENIN ratio
What does a high aldosterone:renin ratio tell you?
PRIMARY hyperaldosteronism
Aet of hyperkalaemia
AKI and CKD
Addisons
Drugs (spironolactone, ACE-I/ARB, NSAID, heparin, beta blockers)
Burns, rhabdomyolysis, trauma
What ECG changes indicate hyperkalaemia?
Loss of P waves
PR prolonged
QRS widened
Peaked T waves
What are the main causes of hypokalaemia?
Diuretics
GI fluid loss (chronic diarrhoea)
hyperaldosteronism (conn’s/cushings etc)
What are the sx of hyperkalaemia/
Fast irregular pulse Chest pain Weakness Palpitations Light-headedness
What are the sx of hypokalamia?
Muscle weakness Hypotonia Hyporeflexia Cramps Tetany palps light-headedness
What should you not do when tx hypokalaemia?
never give IV K+ as fast stat bolus!!
What are the ECG signs of hypokalaemia?
Small T waves
Prominent U waves
Long PR
Depressed ST segment
Which other electrolyte is important to check and correct in hypokalaemia?
magnesium
Define phaeochromocytoma
Catecholamine producing adrenal tumour
What are the main Ix for phaeochromocytoma?
24h urine for metanephrines/metadrenaline
Abdo CT
What is first line tx for phaeochromocytoma?
alpha blockade (e.g. phenoxybenzamine) pre-operation (only give beta blocker once BP controlled)
What molecule is released by tumours in carcinoid syndrome?
Serotonin
What are two of the most common symptoms of carcinoid syndrome?
Flushing
Diarrhoea
Which cells form the tumour in carcinoid tumours?
enterochromaffin cells
What is the 1st line Ix for DI?
water deprivation test
What happens to urine and serum osmolality in DI?
Urine osmolality low
Serum osmolality normal/high
What is the consequence of hydrated a DI patient with severe hypernatraemia too rapidly?
Cerebral oedema
How do you distinguish cranial DI from nephrogenic DI?
Give desmopressin and look for response during water deprivation test
MRI head
What are the three biochemical features of SiADH?
Concentrated urine
Hyponatraemia
Low plasma osmolality
(absence of hypovolaemia or oedema)
What can cause siADH?
Malignancy (e.g. small cell lung Ca)
CNS disorders
TB
drugs
How do you tx hyponatraemia?
Rule out drug causes - THIAZIDE DIURETICS
Tx cause and fluid restrict