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
Describe Secondary Hyperaldosteronism?
Most commonly caused by renal artery stenosis
High Aldosterone, high Renin
Mx = Eplerenone or Spironolactone, renal artery angiography
What should you always test in treatment resistant HTN?
Renin:Aldosterone Ratio to look for hyperaldosteronism
What is an important complication of fluid resus in DKA?
Cerebral oedema, especially in children
How should you correct hyponatraemia?
Slowly! Otherwise there is a risk of cerebral oedema and Osmotic Demyelination Syndrome (aka Central Pontine Myelinosis) - this causes a locked in syndrome
How can we manage the symptoms of Grave’s disease whilst we await definitive treatment?
Propranolol
Mx of DKA?
Start fixed rate insulin infusion. Continue long acting but stop short acting insulins
Which condition are anti-TSH receptor antibodies seen in?
Grave’s disease
What condition are anti thyroid peroxidase (TPO) antibodies seen in?
Hashimoto’s
What is the 1st line Mx of Hypercalcaemia?
IV fluids
Describe Hyperosmolar Hyperglycaemic State?
Seen in those with T2DM secondary to illness, dementia or sedative drugs
Sx = Slow onset dehydration, polyuria/polydipsia, nausea and vomiting, reduced consciousness and hyper viscosity
Ix and Mx of Hyperosmolar Hyperglycaemic State?
Ix = low BP, high glucose, no hyperketonaemia, no acidosis
Mx = IV fluids and VTE prophylaxis. Do not give insulin
What are features which separate Grave’s from other causes of hyperthyroidism?
Exophthalmos, ophthalmoplegia, pretibial myxoedema, thyroid acropachy (digital clubbing, soft tissue swelling of hands/feet, new periosteal bone formation)
How frequently should insulin dependant diabetics check blood glucose whilst driving?
Every 2 hours
You are initiating diabetes treatment for a type 2 diabetic. You want to give Metformin and an SGLT2 inhibitor for organ protection. How should you proceed?
Start metformin. Once tolerability is confirmed add the SGLT2 inhibitor
You are initiating diabetes treatment for a type 2 diabetic. You want to give Metformin and an SGLT2 inhibitor for organ protection. The patient states they can’t tolerate Metformin, how should you proceed?
Treat with SGLT2 monotherapy
How do SGLT2 inhibitors and sulfonylureas affect weight?
SGLT2 inhibitors cause weight loss
Sulfonylureas cause weight gain
What is the most common thyroid cancer? What is the prognosis?
Papillary cancer. It spreads early to the lymph nodes but shows a good prognosis
Name 4 drugs known to cause Galactorrhoea?
Metoclopramide, Domperidone, Haloperidol and Chlorpromazine
Mx of Diabetic peripheral neruopathy?
Amitriptyline (avoid in those with BPH due to risk of urinary retention), Duloxetine (avoid if eGFR <30), Gabapentin and Pregabalin
How can we Mx galactorrhoea?
Bromocriptine
What is Pseudo-Cushing’s?
It can mimic Cushing’s disease. It occurs secondary to alcohol excess or severe depression. Insulin stress test will differentiate it from true Cushing’s
How many units is 1ml insulin?
1000 units
Ix of secondary hypothyroidism?
Low TSH and low T4
Ix = MRI pituitary gland
What are the top 2 causes of Cushing’s syndrome?
Most common = exogenous steroids
2nd most common = pituitary adenoma
How do you diagnose asymptomatic patients with T2DM?
They must have a fasting plasma glucose >=7mmol/l OR a random plasma glucose (OGTT) >=11.1mmol/l OR HbA1c >=48 on 2 separate occasions