Endocrine investigations

Question 1

What is a synacthen test?

Answer 1

A Test done to investigate whether the adrenal gland is producing enough cortisol

Its done to help diagnose Addisons disease

Question 2

What investigations are needed to diagnose a prolactinoma?

Answer 2

1. TFT’s

Question 3

How would you investigate diabetes insipidus? (5 things)

Explain the test that can be done.

Answer 3

1. U+E’s
2. Serum glucose (to rule out DM)
3. Serum and urine osmolality
4. Urine dip
5. Fluid deprivation test

(if diagnosis is unclear)

• The patient is not to drink water for 8 hours. Urine osmolality is measured and Desmopressin is then administered. 8 hours later, urine osmolality is measured again.

Question 4

How would you investigate a prolactioma ?

Answer 4

1. MRI brain scan
   - Space occupying tumour
2. Serum prolactin
   - Increased levels

Question 5

When investigating for hypothyroidism, what would you expect from the TSH, T3 and T4 levels?

Answer 5

TSH
- Will be high (because no negative feedback to the brain, so the pituitary produces lots of TSH to try and get the thyroid working)

T3+T4
- Will be low

Question 6

Why would a fine needle aspiration of the thyroid be done?

Answer 6

To investigate the cause of a thyroid nodule.

Question 7

What is a radioactive iodine uptake test ?

what are 2 indications for doing this scan?

Answer 7

A radio-tracer is swallowed and absorbed. It helps create images of the thyroid. It measures how much of the radioactive iodine is taken up by the thyroid

Indication:

• Assess function of the thyroid
• View thyroid shape, size & position.

Question 8

What is the first line for investigation for acromegaly?

Answer 8

Serum IgF

Question 9

What is the first line diagnostic test for acromegaly?

Answer 9

Oral glucose tolerance test

Question 10

What test do you used to investigate Graves disease?

Answer 10

TSH, T3+T4

Question 11

What tests would you do to investigate Hashimoto’s disease? (4 things)

Answer 11

TSH
T3
TPO antibody (thyroid peroxidase antibody)
Thyroglobulin antibody

Question 12

What is primary hyperparathyroidism and how would you investigate it? (2 things)

Answer 12

Primary hyperparathyroid is caused by a tumour of the parathyroid gland.

Ix:

• High PTH
• High calcium.

investigate via:

• PTH
• Bone profile

Question 13

What is secondary hyperparathyroidism and how would you investigate it? (4 investigations)

Answer 13

Caused by a Vitamin D deficiency or CKD

Ix:

• High PTH
• Low/ normal calcium

Investigate via:

• PTH
• Bone profile
• Vitamin D
• U+E’s

Question 14

What is Cushings disease and how would you investigate it ? (3 things)

Answer 14

Overproduction of cortisol in the body

Ix:

1. 24 Hour urinary free cortisol ** diagnostic
2. Dexamethasone suppression test
3. ACTH

Question 15

How do you investigate SIADH ?

Answer 15

1. Serum Osmolarity/ Osmolality (decreased)
2. Urine Osmolality (Increased)
3. U+E (Low sodium)

Question 16

What is the gold standard for Addisons disease?

Answer 16

ACTH (synacthen) test confirms the diagnosis

Question 17

What condition would cause hyperpigmentation, Hyperkalaemia and hyponatraemia?

Answer 17

Addisons

Question 18

Anti-TPO antibodies are seen in around 90% of patients of which condition?

Answer 18

Hashimoto’s thyroiditis

Anti- TPO antibodies attack the thyroid peroxidase enzyme. The immune system is basically attacking the thyroid gland

Question 19

What is a mild, moderate and severe GCS?

Answer 19

Mild:
13-15

Moderate:
9-12

Severe:
3-8