Endocrinology Flashcards
(49 cards)
What are the primary causes of hypothyroidism?
Atrophic hypothyroidism
Hashimotos thyroiditis
Iodine deficiency
What are secondary causes of hypothyroidism?
Drugs - lithium + amiodarone
Thyroidectomy
What abs may be seen in hypothyroidism?
Anit thyroid peroxidase abs TPO
What are some of the signs of hypothyroidism?
BRADYCARDIC
Reflexes down, ataxia, Dry skin, Yawning (tired), Cold peripheries, Ascites, Round puffy face, Depressed, Immobile +/- ileus, CCF
What are the 3 main causes of hyperthyroidism?
1) Graves disease
2) Toxic multi nodular goitre
3) Solitary toxic adenoma
What abs are associated with hyperthyroidism?
TSH receptor abs
What investigations can you do in hyperthyroidism?
T3, T3, TSH
TSH receptor abs
Thyroid USS
Radioisotope uptake scan
What are the medical options for treating hyperthyroidism?
- Symptomatic: BB - propranolol (stop the conversion of T4–>T3)
- Anti-thyroid: Carbimazole
- Propylthiouracil (for pregnancy or thyroid storm)
What are the SE of carbimazole?
Agranulocytosis + neutropenic sepsis as it causes myelosupression
Give a very brief pathophys behind graves disease
TSH receptor abs mimic TSH –> gland hyperplasia and high T3/T4
Give 4 signs specific to graves disease?
1) Ophthalmoplegia
2) Exopthalmos
3) Pretibial myxoedema
4) Thyroid acropathy
Give some causes of high serum prolactin levels
Benign pituitary adenoma
Hypothyroidism Cushings syndrome
Drugs: AP, Dopamine antagonists (domperidne and metoclopramide) and anti-depressants
At what levels do prolactin have to be to be a true prolactinoma?
> 5000
You suspect your patient has acromegaly, what investigation work up do you do?
- Bloods: BM, phosphate, calcium and triglycerides
- OGTT - glucose should decrease, if no response –> acromegaly
- Serum IGF -1 if normal that excludes acromegaly
- Serum GH (but it has episodic production)
- MRI pituitary and hypothalamus
Explain how the OGTT works to dx acromegaly
With acromegaly they have high GH levels
Hyperglycaemia should have a negative FB on GH and cause a decrease in GH levels
The patients are fasted and then given a glucose solution to drink. Their BM and GH levels are monitored every 30ms and the GH levels do not decrease with increased BMs in acromegaly
What are the medical and surgical treatment options for acromegaly?
M
- somatostatin analogues (inhibits GH) = ocretotide
- GH antagonists = pegvisokmant
S = Tran sphenoidal surgery
What is Cushing’s disease caused by?
Bilateral adrenal hyperplasia from an ACTH secreting pituitary adenoma
What tests can you do to dx someone with cushings syndrome?
1) dexamethasone suppression test (no suppression seen)
2) 24 hour urinary free cortisol
You have dx someone with Cushings syndrome - what do you look at next to determine the cause of the problem?
Drug chart - are the on exogenous steroids?
ACTH high - from the pituitary
- -> pituitary tumour = cushing’s disease
- -> ectopic = NSCLCa
ACTH low - from the adrenals
- ->pituitary adenoma
- -> pituitary carcinoma
What abs are seen in AI Addison’s?
21 hydroxylase Abs
How would a person with Addison’s present?
Thin - anorexia, N+V wt loss
Tanned - ACTH cross reacts with melanin
Tired - fatigue
Tumbling - weakness + faintness due to low BP
How do you dx someone with Addisons?
Short ACTH stimulation test = synactin test
Addisons if there is no increase in cortisol following the synactin (which is a chemical copy of ACTH)
Addisons can be excluded if cortisol levels increase >500
A 55 year old thin, tanned man presents with N + V, fever, muscle cramps and confusion
His ABG shows low sodium and glucose, high K+ and Cr.
What is happening and how do you treat it?
Addison's crisis Rx: IM/IV hydrocortisone 100mg if adult IV fluids (must rehydrate) Further hydrocortisone and glucose
What is Conns disease?
(Opposite of Addison’s)
= Primary hyperaldosteronism
Excessive production of aldosterone independent of RAAS system
Due to adrenal adenoma (80%) // bilateral adrenal hyperplasia
