Endo & Metabolic Flashcards
What is classed as a prolonged QTc? How should you treat it in the context of hypocalcaemia?
> 450 in males and >460 in females
Treat with IV calcium gluconate
Name 4 factors which can give falsely low HbA1c results?
Haemodialysis, sickle cell, G6PD deficiency and Hereditary spherocytosis
Describe Klinefelter’s syndrome?
47 XXY
They will be tall, have small testes and gynaecomastia with little secondary sexual characteristics. These patients are infertile
Will have raised gonadotrophins but low testosterone
What is the single most useful test in diagnosing the cause of hypocalcaemia?
PTH levels
What should you give to anyone with HTN and T2DM?
ACEi or ARB
How do you treat hyperthyroidism in pregnancy?
Propylthiouracil in the 1st trimester then switch to Carbimazole once in the 2nd trimester
What should you start a patient with T2DM on if they have a QRISK3 >10%, HF or CVD (e.g. angina)?
An SGLT2 inhibitor, this is for organ protection
Describe primary hyperparathyroidism?
Most commonly caused by a solitary parathyroid adenoma
Raised PTH and Calcium with low Phosphate
Management = surgery
Describe secondary hyperparathyroidism?
Caused by parathyroid gland hyperplasia due to low Calcium (usually secondary to CKD or vitamin D deficiency)
Raised PTH and Phosphate (if kidney disease), low or normal calcium and low Vitamin D
Management = fix underlying cause
Describe tertiary hyperparathyroidism?
Occurs due to uncontrolled parathyroid hyperplasia after correction of the underlying renal disorder.
VERY raised PTH, normal or high Calcium and normal or low Phosphate
Management = surgical correction
True or false, over replacement of thyroxine can cause osteoporosis?
True
What can lead to a falsely high HbA1c?
Splenectomy, iron deficiency anaemia, B12/folate deficiency and chronic alcoholism
What are the sick day rules in DM?
If on insulin take as normal but check blood sugars more frequently
What is the initial investigation in Cushing’s syndrome?
Low dose (overnight) dexamethasone suppression test. If Cushing’s morning cortisol spike will not be suppressed
You have confirmed Cushing’s syndrome with a low dose dexamethasone suppression test. What should you do next?
Perform a high dose dexamethasone suppression test to establish the cause.
If suppressed ACTH and cortisol = pituitary cause aka Cushing’s disease
If suppressed ACTH but not cortisol = adrenal cause
Neither is suppressed = ectopic ACTH
When is a Short Synacthen test used?
To diagnose Addison’s disease. It will distinguish Addison’s from secondary and tertiary adrenal insufficiency (Synacthen is synthetic ACTH)
Which metabolic abnormality may be seen in Cushing’s syndrome?
Hypokalaemic metabolic alkalosis. This is most pronounced if there is ectopic ACTH e.g. in small cell lung cancer
Describe Primary Adrenal Insufficiency?
Addison’s disease
Occurs due to autoimmune destruction of the adrenal glands or secondary to metastatic malignancy
Low Cortisol and low Aldosterone, raised ACTH
Mx = hydrocortisone and fludrocortisone
Describe Secondary Adrenal Insufficiency?
Inadequate ACTH secretion from the pituitary glands. Can occur secondary to Sheehan’s syndrome in women who have recently gave birth.
Low Cortisol and low ACTH
Describe Tertiary Adrenal Insufficiency?
Inadequate CRH release from the hypothalamus due to long term steroids use being stopped suddenly
Low Cortisol and low ACTH
What symptoms are seen in adrenal insufficiency?
Tired, Tanned, Tearful and Thin
Abdominal pain, muscle cramps, hypotension.
Hyponatraemia and hyperkalaemia if Priamary.
Sx and Mx of an Addisonian Crisis?
Reduced consciousness, low glucose, low BP, low Na+ and high K+
Give IV hydrocortisone and fluid resus
Sx of Hyperaldosteroneism?
HTN (most common cause of secondary HTN), low K+, high Na+ and low H+ (alkalosis)
Describe Primary Hyperaldosteronism?
Most commonly caused by an adrenal adenoma, known as Conn’s syndrome
High Aldosterone, low Renin
Mx = Eplerenone or Spironolactone, surgical removal of adenoma