Endocrinology Flashcards
What are the two main causes of hypercalcaemia?
Primary Hyperparathyroidism
Malignancy e.g. multiple myeloma, bone metastasis
How does hypercalcaemia present?
Bones, stones, moans, groans
Bone pain/fracture
Renal calculi / renal colic
Depression
How does hypercalcaemia show on an ECG?
Short QT interval
How is hypercalcaemia treated?
Rehydration with normal saline
What are the causes of hypocalcaemia?
Vitamin D deficiency
Chronic kidney disease
Primary hypoparathyroidism
Pseudohypoparathyroidism
How does hypocalcaemia present?
Tetany - muscle twitching/cramping
Parasthaesia
Trousseau’s sign
Chvostek’s sign
How does hypocalcaemia show on an ECG?
Prolonged QT interval
How is hypocalcaemia managed?
IV Calcium Gluconate
10ml of 10% over 10 minutes
What is Cushing’s Syndrome?
The signs and symptoms due to prolonged cortisol excess
What is Cushing’s Disease?
Increased cortisol due to a pituitary adenoma secreting ACTH
How does Cushing’s Syndrome present?
Moon face
Central obesity
Proximal limb wasting
Buffalo hump
Hyperglycaemia
Hypertension
Osteoporosis
Depression
What are ACTH dependent causes of Cushing’s?
Cushing’s Disease
Ectopic ACTH secreted from small cell lung cancer
What are ACTH independent causes of Cushing’s?
Steroids
Adrenal adenoma
Adrenal carcinoma
How is Cushing’s Syndrome investigated?
Overnight Dexamethasone suppression test
What is seen on 8mg Dexamethasone suppression test for Cushing’s Disease?
Suppressed ACTH, suppressed cortisol
What does it mean if the 8mg Dexamethasone suppression test suppresses ACTH but not cortisol?
ACTH independent Cushing’s - adrenal adenoma, adrenal carcinoma
What does it mean if both ACTH and cortisol are still high after 8mg Dexamethasone suppression test?
Ectopic ACTH production e.g. from small cell lung cancer
What is the main cause of primary hypoadrenalism?
Addison’s disease
What are causes of secondary adrenal insufficiency?
Due to the pituitary not producing enough ACTH - may be due to surgery/trauma/radiotherapy
What is tertiary hypoadrenalism?
Hypothalamus not producing enough corticotrophin releasing hormone - usually due to long term steroid use
How does adrenal insufficiency present?
Lethargy, weakness
Weight loss
Salt-craving
Hypoglycaemia
Hyponatraemia
Hyperkalaemia
How is adrenal insufficiency investigated?
Short synacthen test - Synacthen given and cortisol levels measured before and after (Synacthen is synthetic ACTH and stimulates adrenal hormone release)
Can also measure 9am cortisol
How is hypoaldrenalism managed?
Hydrocortisone + fludrocortisone
How does an Addisonian crisis present?
Hypotension Hypoglycaemia Reduced consciousness Hyponatraemia Hyperkalaemia
How is an Addisonian crisis managed?
100mg stat hydrocortisone
What are the two main causes of hyperaldosteronism?
Adrenal adenoma (conn’s syndrome) Bilateral idiopathic adrenal hyperplasia
How does hyperaldosteronism present?
Hypertension
Hypokalaemia- may present as muscle weakness
How is bilateral adrenal hyperplasia managed?
Aldosterone antagonist (Spironolactone)
How does type 1 diabetes present?
Polyuria
Polydipsia
Weight loss
What blood glucose is needed to diagnose type 1 diabetes?
Fasting >7
Random >11.1
What autoantibodies can be seen in T1DM?
Anti-GAD
Insulin autoantibodies
Islet cell antibodies
How is type 1 diabetes managed?
Insulin therapy
How does DKA present?
Polyuria Polydipsia Dehydration Abdominal pain Kussmaul breathing Acetone smelling breath
What lab results are seen in DKA?
Raised ketones
Raised blood pH (metabolic acidosis with raised anion gap)
Raised glucose
Low bicarbonate
How is DKA managed?
1) fluid resus with 0.9% sodium chloride
2) IV Insulin at 0.1 units/kg/hour
3) potassium replacement
What are modifiable risk factors for T2DM?
Obesity
Sedentary lifestyle
High carb diet
What are non-modifiable risk factors for T2DM?
Ethnicity
Family history
Old age
How is T2DM investigated?
Fasting glucose >7
Random glucose >11.1
HbA1c >48
How is T2DM managed?
1) Metformin
2) add: Sulfonylurea/gliptin/pioglitazone/SGLT-2 inhibitor
3) add another
4) insulin
Add another if HbA1c is above 58
What are side effects of Metformin?
Diarrhoea
Abdominal pain
Lactic acidosis
When is Metformin contraindicated?
Chronic kidney disease
Recent MI
Alcohol abuse
Note: stop Metformin in acidosis
Which diabetic drug can cause hypoglycaemia?
Sulfonylurea (keep HbA1c at 53)
What are side effects of sulfonylurea?
Weight gain
Hypoglycaemia
Which diabetic drug is CI in pregnancy and breastfeeding?
Sulfonylurea
What are side effects of a gliptin (DPP4 inhibitor)?
Symptoms of URTI
GI tract upset
Pancreatitis
NOT THAT EFFECTIVE
What are side effects of a pioglitazone e.g. Thiazolidinedione?
Weight gain
Increased risk of bladder cancer (CI in bladder cancer)
Fluid retention
Increased risk of fractures
How does hypoglycaemia present?
Sweating Shaking Anxiety Hunger Nausea
What is the most common cause of hypothyroidism?
Hashimoto’s thyroiditis
How does hypothyroidism present?
Weight gain Menorrhagia Cold intolerance Constipation Dry skin
What autoantibodies are seen in Hashimoto’s?
Anti-thyroglobulin antibodies
Anti-TPO antibodies
How is hypothyroidism managed?
Levothyroxine
What are side effects of levothyroxine?
Hyperthyroidism
Reduced bone mineral density
(osteoporosis)
Worsening of angina
AF
What medications interact with levothyroxine?
Iron tablets and calcium carbonate
Allow 4 hours gap
What TFTs are seen in hypothyroidism?
High TSH
Low T3/T4
What is the most common cause of hyperthyroidism?
Graves’ disease
How does hyperthyroidism present?
Weight loss Mania Heat intolerance Excessive sweating Oligomenorrhea Pretibial myxoedema Diarrhoea
What autoantibody is seen in Graves’ disease?
Anti-TSH antibodies
What extra symptoms are seen in Graves’ disease?
Exophthalmos
Pretibial myxoedema
What are other causes of hyperthyroidism?
Toxic multinodular goitre
Solitary toxic thyroid nodule
Subacute thyroiditis
What is the presentation of subacute thyroiditis?
Hyperthyroidism after a viral infection
Self-limiting
TENDER goitre
How is hyperthyroidism managed?
1) symptomatic relief with propranolol
2) anti-thyroid drug: Carbimazole
3) radioactive iodine
4) thyroidectomy
What is a thyroid storm?
Life threatening complication of hyperthyroidism
Precipitated by illness/surgery/trauma
How does thyroid storm present?
High-grade fever
Confusion/agitation
Hypotension
Tachycardia
Nausea and vomiting
Treated with = Propranolol + Steroid (e.g. Hydrocortisone) + Anti-thyroid drug (Carbimazole/Propylthiouracil)
How is thyroid storm managed ?
Propranolol + Steroid (e.g. Hydrocortisone) + Anti-thyroid drug (Carbimazole/Propylthiouracil)
What is the role of parathyroid hormone?
Increased calcium by:
Increasing calcium reabsorption
Inhibiting osteoclasts
Stimulating kidneys to convert vitamin D3 to calcitriol
What is primary hyperparathyroidism? What is the most common cause?
Usually due to an adenoma of the parathyroid gland
What lab results are seen in primary hyperparathyroidism?
High parathyroid hormone
High calcium
Low phosphate
What is secondary hyperparathyroidism?
High parathyroid hormone due to:
Reduced dietary intake of vitamin d
Chronic kidney disease
High PTH
normal calcium
What is tertiary hyperparathyroidism?
After there has been secondary hyperparathyroidism for a long time.
Causes hyperplasia of the parathyroid.
Once underlying cause is treated, still increased PTH
High PTH, high calcium
What are the symptoms of hyperparathyroidism?
Same symptoms of hypercalcaemia Bones, groans, stones, moans Bone pain/fractures Renal stones Depression
What is the main cause of hypoparathyroidism?
Usually secondary to thyroid surgery
How does hypoparathyroidism present?
Presents with hypocalcaemia
Tetany - muscle twitching/cramping
Parasthesia
Chvostek’s sign – twitching of facial muscles in response to tapping over facial nerve
Trousseau’s sign - carpopedal spasm of the hand and wrist occurs after an individual wears a blood pressure cuff inflated over their systolic blood pressure for 2 to 3 minutes
What is pseudohypoparathyroidism?
Target cells are not sensitive to PTH
High PTH
Low calcium
What is Acromegaly?
Excess growth hormone
What is the main cause of acromegaly?
Pituitary adenoma
What are features of acromegaly?
Large tongue
Large nose
Large hands and feet
Protruding jaw
Prominent forehead
Skin tags
Excess sweating
Symptoms of tumour - headaches, bitemporal hemianopia
What is the initial investigation conducted in acromegaly?
Insulin-like growth factor
What next test is conducted for acromegaly if ILGF-1 is positive?
Oral glucose tolerance test
How is acromegaly managed?
Trans-sphenoidal removal of pituitary tumour
If surgery not suitable - somatostatin analogue e.g. octreotide
What is a pituitary adenoma?
A benign pituitary tumour
How does a pituitary adenoma present?
Symptoms of excess hormone being produced (prolactin, growth hormone or ACTH to cortisol)
Symptoms of pituitary tumour (hypopituitarism, bitemporal hemianopia, headaches)
What is a prolactinoma?
A prolactin secreting pituitary adenoma
How does a prolactinoma present?
In women - amenorrhoea, galactorrhoea, infertility
In men - impotence, lack of libido, galactorrhoea
How is a prolactinoma managed?
Dopamine agonists - bromocriptine or cabergoline
If this fails - trans sphenoidal removal
What is diabetes insipidus?
Low ADH
What are the two types of diabetes insipidus?
Nephrogenic and cranial
Which drug most commonly causes nephrogenic diabetes insipidus?
Lithium
How does diabetes insipidus present?
Polyuria and polydipsia
Does diabetes insipidus have high or low urine osmolality?
Low urine osmolality
How is diabetes insipidus investigated?
Fluid deprivation test
No fluid for 8 hours - test urine osmolality
Then give desmopressin and Check again in 8 hours
Cranial DI - urine osmolality high after giving desmopression
Nephrogenic DI - urine osmolality still low
How is diabetes insipidus treated?
Cranial - desmopressin
Nephrogenic - thiazide diuretics
What is SIADH?
Excess ADH
What electrolyte imbalance is seen in SIADH?
Hyponatraemia
What do you have to be careful of when treating severe hyponatraemia?
Central pontine myelinosis
How is SIADH treated?
Tolvaptan
What is the most common type of thyroid cancer?
Papillary
Which thyroid cancer has the best prognosis?
Papillary
What is a phaeochromocytoma?
Adrenal tumour secreting catecholamines (adrenaline and noradrenaline)
How is phaeochromocytoma treated?
Definitive management - surgery
1) stabilise patient with alpha blocker - Phenoxybenzamime
2) then beta blocker - propranolol
Which type of thyroid cancer is associated with increased calcitonin?
Medullary
Why do you have to be careful with fluid resus in DKA in children and young adults?
Can cause cerebral oedema
How does cerebral oedema present?
Headache, irritability, visual disturbances, confusion
Which diabetes drug is associated with weight loss?
SGLT-2 inhibitor ( -gliflozin)
What is the main side effect of carbimazole?
Agranulocytosis
What does HbA1c need to be to add another diabetic drug to someone who has T2DM?
58 or over
What are macro vascular complications of diabetes?
Coronary artery disease
Peripheral ischaemia
Stroke
HTN
What are micro vascular complications of diabetes?
Peripheral neuropathy
Retinopathy -proliferative
Nephropathy - glomerulonephritis
What is gastroparesis? How is it managed?
Complication of diabetes
Delayed gastric emptying - food held in stomach longer than usual
Causes nausea/vomiting
Abdominal pain
Feeling of fullness/bloating
Management = Domperidone/Metoclopramide
What is subclinical hypothyroidism? How is subclinical hypothyroidism managed?
Raised TSH but normal T3/T4
If TSH 4-10:
If under 65 + symptomatic = Levothyroxine.
Otherwise - watch and wait
If TSH >10
Under 70 = Levothyroxine
Older than 70 = watch and wait
What is the action of aldosterone?
Increases sodium+water absorption
Increases potassium excretion
Increases BP
How can diabetes be diagnosed in a patient with haemoglobinopthy?
Oral glucose tolerance testing
Can’t do HbA1c because of haemaglobin
Which drugs can cause gynaecomastia?
Spironolactone
Digoxin
Finasteride
Goserelin
What are causes of gynaecomastia? (Non-drug)
Physiological – normal in puberty Kallman’s/Klinefelter’s Testicular failure Liver disease Testicular cancer Drugs
What happens to C-peptide levels in T1DM?
Low
What is bitemporal hemianopia and what can cause this?
Loss of vision in both eyes on temporal side
Due to damage to the optic chiasm - due to tumours e.g. pituitary tumour
What is the role of ADH?
Increased water absorption at the DCT and collecting duct
What is the role of aldosterone?
Increased sodium reabsorption
Increased potassium excretion
Increases BP
Why does hypocalcaemia occur in CKD?
Decreased renal production of vitamin D –> Decreased calcium absorption
How is postpartum thyroiditis managed?
Watch and wait
What are the three types of multiple endocrine neoplasia?
MEN type I = 3 P’s
Hyperparathyroid, pituitary, pancreas (insulinoma, gastrinoma)
Hypocalcaemia
MEN type IIa
2 P’s - parathyroid + phaeochromocytoma
Medullary thyroid cancer
MEN type IIb
1 P - Phaeochromocytoma
Marfanoid body habits
What is pituitary apoplexy?
Sudden enlargement of a pituitary tumour (usually non-functioning macroadenoma) secondary to haemorrhage or infarction.
What are precipitating factors of a pituitary apoplexy?
HTN
Pregnancy
Trauma
Anticoagulation
What are features of a pituitary apoplexy?
Sudden onset headache similar to that seen in subarachnoid haemorrhage
Vomiting
Neck stiffness
Visual field defects: classically bitemporal superior quadrantic defect
Extraocular nerve palsies
Features of pituitary insufficiency
e.g. hypotension/hyponatraemia secondary to hypoadrenalism
How is pituitary apoplexy diagnosed?
MRI Head
How is pituitary apoplexy managed?
Urgent steroid replacement
Careful fluid balance
Definitive = surgery
Which visual defect is seen in pituitary apoplexy?
Classically bitemporal superior quadrantic defect
Bitemporal superior quadrantinopia
What is sick euthyroid syndrome?
How is it managed?
Everything low - TSH, T3, T4
Or TSH inappropriately normal with low T3 and T4
No thyroid abnormality
No treatment needed - usually recovers after recovery from systemic illness
What is carcinoid syndrome? How does it present?
A rare, slow growing malignant tumour that develops in the neuroendocrine system
Usually from liver mets
Abdominal pain
Diarrhoea
Flushing
Bronchospasm
How is carcinoid syndrome diagnosed?
Raised urinary 5-HIAA
How is carcinoid syndrome managed?
Octreotide (somatostatin analogue)
How is pheochromocytoma diagnosed?
24 hour urinary collection of metanephrines
What is a myxoedema coma? How does it present?
Complication of untreated hypothyroidism
Confusion Hypothermia Bradycardia Hyporeflexia Seizures
How is myxoedema coma managed?
IV thyroid replacement + IV hydrocortisone (until co-existing adrenal insufficiency has been excluded)
How is hyperaldosteronism investigated/diagnosed?
First line investigation for hyperaldosteronism = Plasma aldosterone/renin ratio
If abnormal –> CT Abdomen, adrenal venous sampling (To differentiate cause).
What is the diagnostic criteria for hyperosmolar hyperglycaemic state?
- Hypovolaemia
- Hyperglycaemia (No ketonaemia or acidosis)
- High serum osmolality
How is hyperosmolar hyperglycaemic state managed?
Mainstay = 0.9% Sodium Chloride
This will reduce hyperglycaemia and treat serum osmolality
Check serum osmolality frequently
Can add insulin but only once glucose is no longer dropping with just fluids