Endocrine

Question 1

What causes a primary adrenal insufficiency? (5)

Answer 1

Adrenal gland affected:
Addison's disease
Malignancy e.g. adrenal mets, lymphoma
Infection e.g. TB, HIV
Adrenal haemorrhage 
Congenital adrenal hyperplasia

Question 2

What causes a secondary adrenal insufficiency?

Answer 2

Pituitary gland dysfunction e.g. radiation, Sheehan syndrome

Question 3

What causes a tertiary adrenal insufficiency?

Answer 3

Hypothalamus gland dysfunction e.g. long-term steroids suppresses activity

Question 4

What signs are present in Addison’s disease? (2)

Answer 4

Hyperpigmentation

Postural hypotension

Question 5

What special test do you use to diagnose Addison’s disease?

Answer 5

Short Synacthen test (ACTH stimulation test)

Question 6

What blood tests are required to investigate Addison’s (apart from FBC, LFTs, U&Es)? (6)

Answer 6

Cortisol
ACTH (differentiates between primary and secondary)
Renin (high) and aldosterone (low)
Adrenal autoantibodies
Glucose

Question 7

What electrolyte abnormalities would you expect in Addison’s? (5)

Answer 7

Low sodium and raised potassium

Other: low calcium and glucose, raised urea

Question 8

What is the management of an Addisonian crisis?

Answer 8

Hydrocortisone 100mg STAT then every 6h
Monitor fluid balance
Monitor U&Es, glucose and ECG

Question 9

What are the main pituitary dependent causes of Cushing’s? (2)

Answer 9

Cushing’s disease (pituitary adenoma)
Ectopic production e.g. SCLC producing ACTH

In these cases, the rise in cortisol is due to increase in ACTH; therefore will have raised ACTH in bloods

Question 10

What are the main pituitary independent causes of Cushing’s?

Answer 10

Iatrogenic i.e. taking steroids - ACTH will be decreased due to negative feedback
Adrenal adenoma - cortisol production no longer listens to ACTH

In these cases, the ACTH will be low due to negative feedback; therefore will have low ACTH in bloods

Question 11

What special test diagnoses Cushing’s syndrome?

Answer 11

Dexamethasone suppression test

If suppressed on 1mg dexamethasone, rules out dexamethasone
Then give 8mg

Question 12

What is a probable diagnosis?

1. High dose dexamethasone - cortisol suppressed, ACTH raised
2. High dose dexamethasone - cortisol, not suppressed, ACTH raised
3. High dose dexamethasone - cortisol, not suppressed, ACTH low

Answer 12

1. Pituitary adenoma (Cushing’s disease)
2. Ectopic ACTH
3. Adrenal adenoma

Question 13

What would you expect to see on an ABG for Cushing’s syndrome?

Answer 13

Hypokalaemic metabolic alkalosis

This is because an excess of mineralcorticoids causes sodium to be retained (causing hypertension) and potassium and hydrogen to be lost (K+ and H+ have same transporter)

Question 14

So you’ve successfully diagnosed Cushing’s syndrome, now how would you find the culprit?

1. Suspecting pituitary adenoma
2. Suspecting ectopic or adrenal adenoma

Answer 14

1. MRI of pituitary and bilateral inferior petrosal sinus sampling (IPSS)
2. CT TAP

Question 15

What are the causes of primary hyperaldosteronism?

Answer 15

Conn’s syndrome (adenoma), bilateral adrenal hyperplasia

Question 16

What are the causes of secondary hyperaldosteronism?

Answer 16

Anything that raises renin e.g. renal artery stenosis, renin-secreting tumour, fibromuscular dysplasia, coarctation of aorta, diuretics

Question 17

What is hyperaldosteronism most likely to present with?

Answer 17

Hypertension

Question 18

What would you likely see on an ABG in hyperaldosteronism?

Answer 18

Hypokalaemic metabolic alkalosis

Question 19

What special test is used in hyperaldosteronism?

Answer 19

Aldosterone-renin ratio

Question 20

What is the medical management of hyperaldosteronism?

Answer 20

K+ sparing diuretics e.g. spironolactone, eplerenone

Question 21

What are some secondary causes of diabetes?

Answer 21

Pancreatic disease e.g. chronic pancreatitis, cystic fibrosis, haemochromatosis
Endocrine e.g. Cushing’s, thyrotoxicosis, acromegaly
Medication e.g. steroids, atypical antipsychotics, thiazide diuretics

Question 22

What is the diagnostic criteria for diabetes, assuming they have symptoms? (3)

Answer 22

Random blood glucose >11.1
Fasting glucose >7.0
HbA1c >48 (not suitable for type 1 or secondary cause)

If no symptoms, need 2 tests on different days to diagnose

Question 23

What is the diagnostic criteria for impaired glucose tolerance?

Answer 23

Fasting glucose 6.1-6.9 AND 2h post glucose >7.8, <11.1

HbA1c 42-47

Question 24

What initial bloods would you get when investigating diabetes (apart from glucose)?

Answer 24

U&Es, eGFR, urine ACR
Full lipid profile, HbA1c
TFTs, coeliac screen

Question 25

What tests can you order if you are not sure if it is type 1 or type 2 diabetes? (2)

Answer 25

C-peptide and autoantibodies (e.g. anti-GAD, IAA)

Question 26

Can you name the type of diabetic drug and the common side effects? 1. Metformin 2. Sitagliptin 3. Exanetide 4. Gliclazide 5. Dapagliflozin 6. Pioglitazone

Answer 26

1. Biguanide - diarrhoea, nausea, lactic acidosis 2. DDP-4 inhibitor - GI upset, pancreatitis 3. GLP-1 mimetic - GI upset, asthenia, NB women must be on effective contraception 4. Sulfonylurea - weight gain, hypoglycaemia 5. SGLT-2 inhibitors - UTIs, weight loss 6. Thiazolidinediones - weight gain, fluid retention, bladder cancer, osteoporosis, heart failure

Question 27

Which of the type 2 medications is not used for dual therapy and when is it used?

Answer 27

Exanetide - only used if BMI >35 and insulin contraindicated

Question 28

What is the management for hypoglycaemia?

Answer 28

If alert, can give glucose orally e.g. glucogel, sugar lumps, Lucozade and cola If cannot take orally, give IV glucose 20% in a large vein or IM glucagon

Question 29

What is the management for DKA? (7)

Answer 29

F - fluids I - rapid acting insulin, fixed rate 0.1U/kg/h G - closely monitor, give 10% dextrose after if falls below 14 P - monitor potassium I - infection and other triggers (look for them) C - chart fluid balance K - ketones (monitor hourly) When in doubt, follow the local DKA protocol!

Question 30

What are the stages of diabetic retinopathy? (3)

Answer 30

1. Background - microaneurysms and hard exudates 2. Pre-proliferative - cotton wool spots, dot and blot haemorrhages 3. Proliferative - symptomatic e.g. floaters or sudden vision loss; at risk of vitreous haemorrhage

Question 31

What are the driving rules for type 1 diabetes? (4)

Answer 31

Must notify the DVLA Carry glucose with you Check BM before driving and every 2h - must be at least 5mmol If BM low, stop, eat something sugary and wait 45 minutes

Question 32

What special test is used for SIADH and what results would confirm it?

Answer 32

Urine and serum osmolality (and urine and serum Na+) urine osmolality and sodium - high serum osmolality and sodium - low

Question 33

What are some causes of SIADH?

Answer 33

``` Small cell lung cancer Infection e.g. atypical pneumonia Abscess Drugse.g. lithium, carbemazepine, NSAIDs, antipsychotics Head injury ``` Hypothyroidism Postoperative

Question 34

What other blood tests would you order when investigating SIADH?

Answer 34

TFTs (exclude hypothyroidism) | K+ and possibly short Synacthen test (exclude Addison's)

Question 35

What is the special test for diabetes insipidus?

Answer 35

Fluid deprivation test

Question 36

What do these results from the water deprivation test suggest? 1. Before <300, after DDVAP >800 2. Before <300, after <300 3. Before >800, after >800

Answer 36

Cranial (as back to normal after giving ADH) Nephrogenic (not due to lack of ADH) Psychogenic or primary polydipsia

Question 37

What are some causes of diabetes insipidus?

Answer 37

Cranial - tumour, infection, haemorrhage, Wolfram's | Nephrogenic - hypokalaemia, hypercalcaemia, CKD, RTA, pregnancy, medication e.g. orlistat, lithium, congenital

Question 38

What is the management for SIADH?

Answer 38

Consult a specialist before commencing treatment Consider cause Usually fluid restrict or give tolvaptan

Question 39

What autoantibody is used to test for: 1. Hashimoto's? 2. Grave's?

Answer 39

1. Thyroid peroxidase antibody (TPOAb) | 2. Thyroid stimulating hormone receptor antibody (TRAb)

Question 40

What are some causes of hyperthyroidism? (4)

Answer 40

Grave's disease Toxic multinodular goitre Solitary nodule De Quervain's thyroiditis

Question 41

What scans can you get to investigate a thyroid nodule? (2)

Answer 41

Thyroid USS | Thyroid uptake scan (high uptake in hyperthyroidism, low in cancer)

Question 42

What are the most important side effects of carbimazole and propythiouracil? (2)

Answer 42

Agranulocytosis | Foetal abnormalities

Question 43

What are the management options for hyperthyroidism? (3)

Answer 43

Medication e.g. beta blocker for symptoms, PTU, carbimazole Surgery Radioiodine

Question 44

What are some causes of hypothyroidism? (5)

Answer 44

``` Hashimoto's Iodine deficiency Infiltration e.g. sarcoidosis, amyloidosis, haemochromatosis Medication e.g. amiodarone, lithium Pituitary failure e.g. Sheehan ```

Question 45

What is the most common type of thyroid cancer?

Answer 45

Papillary thyroid carcinoma

Question 46

What type of thyroid cancer arises from the C-cells?

Answer 46

Medullary thyroid carcinoma