endo

Question 1

what are the 2 types of diabetes insipidus ?

Answer 1

cranial and nephrogenic

Question 2

what are Cx of cranial diabetes insipidus ?

Answer 2

• head injury
• brain tumours
• brain infections (meningitis, encephalitis, TB)
• brain surgery / radiotherapy

Question 3

what are Cx of nephrogenic diabetes insipidus?

Answer 3

• drugs - lithium
• intrinsic kidney disease
• genetic
• hypokalaemia / hypercalcaemia

Question 4

Sx of diabetes insipidus?

Answer 4

• polyuria
• polydipsia
• hypernatremia

Question 5

how would you Dx diabetes insipidus?

Answer 5

Water deprivation test
Results:
Low after deprivation, high after ADH = cranial
Low after deprivation, low after ADH = nephrogenic
High after deprivation, high after ADH = primary polydipsia

Question 6

Mx of diabetes insipidus ?

Answer 6

Tx underlying Cx

Desmopressin (synthetic ADH):
cranial - replaces ADH
nephrogenic - higher doses + close monitoring

Question 7

CFs of hypercalcaemia?

Answer 7

bones, groans, stones, psychic moans
shortened QT
HTN
corneal calcification

Question 8

main Cx of hypercalcaemia?

Answer 8

1. primary parathyroidism

2. malignancy

Question 9

Tx of hypercalcaemia?

Answer 9

1. Rapid rehydration - 3/4 L/day followed by bisphosphonates

Question 10

WHat are the 2 causes of primary hyperaldosteronism?

Answer 10

• bilateral idiopathic adrenal hyperplasia (70%0
• Adrenal adenoma (Conn’s)
• Adrenal carcinoma - rare

Question 11

What are the CF of primary hyperaldosteronism?

Answer 11

• HTN
• hyperkalaemia (muscle weakness)
• alkalosis

Question 12

Paul is a 49-year-old man who has hypertension which has been difficult to treat. He is currently on three anti-hypertensive medications and his blood pressure is still borderline.

When reviewing the results of his recent routine blood tests, you detect a hypokalaemia which has been recurrent for the past year.

You consider that there may be an underlying diagnosis of primary hyperaldosteronism and arrange referral to a specialist.

Which of the following is the most appropriate first-line investigation?

Answer 12

plasma aldosterone/renin ratio - 1st line suspected primary hyperaldosteronism
should show high aldosterone levels alongside low renin levels (negative feedback due to sodium retention from aldosterone)

high-res CT used to differentiate between Cx. If CT normal, adrenal venous sampling used to distinguish

Question 13

How is primary hyperaldosteronism tx?

Answer 13

adrenal adenoma - surgery

bilateral adrenaocortical hyperplasia - spironolactone

Question 14

A 52-year-old man presents to his GP as he is concerned about a discharge from his nipples. Which one of the following drugs is most likely to be responsible?

Answer 14

Chlorpromazine

other drugs causing galactorrhoea / raised prolactin:

• metoclopramide, domperidone
• phenothiazines
• haloperidol
• very rare: SSRIs, opioids

Question 15

What drugs could cause gynaecomastia?

Answer 15

Drug causes of gynaecomastia
spironolactone (most common drug cause)
cimetidine
digoxin
cannabis
finasteride
GnRH agonists e.g. goserelin, buserelin (used in prostate cancer)
oestrogens, anabolic steroids

Question 16

Addisons blood test results:

Answer 16

hyponatraemia
hyperkalaemia
hypoglycaemia

Question 17

Addison’s Dx test:

Answer 17

Short synacthen test

Question 18

What Cx Addison’s?

Answer 18

Autoimmune destruction of the adrenal gland –> adrenal insufficiency –> lack of cortisol and aldosterone

Question 19

CF of Addisons:

Answer 19

lethargy, weakness, anorexia, nausea & vomiting, weight loss, ‘salt-craving’
hyperpigmentation (especially palmar creases)*, vitiligo, loss of pubic hair in women, hypotension, hypoglycaemia
hyponatraemia and hyperkalaemia may be seen
crisis: collapse, shock, pyrexia

Question 20

Mx of Addison’s / Adrenal insufficiency?

Answer 20

Hydrocortisone (replace cortisol) and fludrocortisone (replace aldosterone)