Endocrinology Flashcards
What is Addison’s? Describe the key presenting features and the treatment
Autoimmune destruction of adrenal glands = reduced cortisol and aldosterone
Signs and sx: (picture a shrivelled person)
-lethargy, weakness, n&v, weight loss, ‘salt-craving’
-hypoglycaemia, hypotension
-hyperpigmentation (esp palmar creases), vitiligo, loss of pubic hair in women
-hyponatraemia and hyperkalaemia (sometimes)
crisis: collapse, shock, pyrexia
Tx:
hydrocortisone to replace cortisol
fludrocortisone to replace aldosterone
(the hydrocortisone dose is split with the majority given in the first half of the day)
Addison’s patient with intercurrent illness →
double the glucocorticoids, keep fludrocortisone dose the same
What is the cause of Addisonian crisis in patients with poorly controlled HIV? Tx?
Cytomegalovirus (CMV)-related necrotising adrenalitis
Give IV hydrocortisone first and then fluid replacement
Thyrotoxicosis is excess circulating T3 and T4. What symptoms might someone present with? Tx?
- sx include heat intolerance, palpitations, anxiety, fatigue, weight loss, muscle weakness
- tx is carbimazole - high dose for 6 weeks then reduced, can cause agranulocytosis (immunodeficiency)
Why is dexamethasone good for raised ICP secondary to brain tumours?
It combines high glucocorticoid (anti-inflammatory) activity with minimal mineralocorticoid (fluid-retention) effects
Side effects of long term systemic corticosteroids?
- Cushing’s syndrome
- weight gain
- immunosuppression
- increased risk of osteoporosis, fractures, and avascular – necrosis of fem. head
- risk of intracranial hypertension
- can cause neutrophilia
What can be seen on ABG in Cushing’s?
hypokalaemic metabolic alkalosis (excess ACTH lowers K+ )
In suspected T1DM, what atypical factors would prompt you to consider additional tests?
age 50 years or above, BMI of 25 kg/m² or above, slow evolution of hyperglycaemia or long prodrome
What is MODY? How should it be treated?
Maturity-onset diabetes of the young: autosomal-dominant disease
- development of T2DM in patients younger than 25 years old
- C-peptide remains in the normal range and beta-cell antibodies are -ve
Treatment is a sulfonylurea
How will C peptide levels differ in T1 and T2 diabetes?
C-peptide will be low in individuals with type 1 diabetes mellitus (as the pancreas is not making enough insulin precursor, which breaks down to form C-peptide and insulin), and normal or high in individuals with type 2 mellitus.
what are the HbA1c targets in T2DM?
48 mmol/mol or 53 mmol/mol in patients with drugs that may cause hypoglycaemia e.g. sulfonylureas
What is the stepladder of tx for T2DM?
You can titrate up metformin (slowly) and encourage lifestyle changes to aim for a HbA1c of 48 mmol/mol, but should add a second drug if the HbA1c rises to 58 mmol/mol.
metformin + DPP-4 inhibitor
metformin + pioglitazone
metformin + sulfonylurea
metformin + SGLT-2 inhibitor
When should modified release metformin be used?
in patients who cannot tolerate metformin due to gastrointestinal symptoms such as diarrhoea
What drug should be added to metformin (in T2DM management) if the patient has existing CVD, HF or a risk of developing either?
Gliflozins should be added if the patient has existing CVD, HF or a risk of developing either bc helps glucose control and sodium simultaneously
What is the first line tx for all hypertensive diabetic patients ?
ARBs
Who should you never give gliptins to?
Patients with pancreatitis
Who should you avoid gliclazides in?
Patients with a raised BMI
What are the diabetes sick day rules?
when unwell, If a patient is on insulin, they must not stop it due to risk of DKA. They should continue their normal insulin regime but ensure that they are checking their blood sugars frequently
Key points:
- Check BM more regularly
- Aim to drink 3L of fluid per day
- Sugary drinks should be used only if pt is struggling to eat normally
- Phone should be nearby in case of emergency
How do patients in DKA present?
Presents with abdo pain, hyperventilation (Kussmaul respiration) and acetone on the breath
Bloods show metabolic acidosis and hyperglycaemia (‘unrecordable’ blood glucose always means that the blood sugar is high rather than low)
How should DKA be treated?
- isotonic saline should be used initially, even if the patient is severely acidotic
- then fixed rate IV insulin at 0.1ml /kg/hr
- electrolytes should be corrected
- long acting insulin should be started and short acting should be stopped
How is DKA resolution measured? What if it doesn’t resolve?
- pH >7.3 and
- blood ketones < 0.6 mmol/L and
- bicarbonate > 15.0mmol/L
If the ketonaemia and acidosis have not been resolved within 24 hours then the patient should be reviewed by a senior endocrinologist
What is the first line tx for diabetic neuropathy?
What other treatments are available?
amitriptyline, duloxetine, gabapentin or pregabalin
tramadol may be used as ‘rescue therapy’ for exacerbations of neuropathic pain
topical capsaicin may be used for localised neuropathic pain (e.g. post-herpetic neuralgia)
pain management clinics may be useful in patients with resistant problems
What are the key features of Grave’s disease on examination and on investigation?
On examination:
Smooth enlarged non tender goitre (tender would be viral thyroiditis)
Exophthalmos (proptosis) and chemosis (bulging, swollen eyes)
pretibial myxoedema, clubbing
On investigation:
+ve TSH receptor stimulating antibodies
On thyroid scintigraphy will see diffuse inc. uptake of iodine
what is first line for 1. immediate control of symptoms and 2. maintaining euthryoidism in Grave’s disease?
- propanolol
- Carbimazole - particularly if there is marked thyrotoxicosis and the patient is elderly/has underlying CVD
What malignancy is Hashimoto’s associated with?
MALT lymphoma
Give the 3 key features of Hashimoto’s (autoimmune) thyroiditis
Hashimoto’s= hypothyroidism + goitre (firm non-tender) + anti-TPO antibodies
What is the most common metabolic condition in cancer patients?
Hypercalcaemia
Most common cause of hypercalcaemia?
Malignancy is the most common cause of hypercalcaemia in hospitalised patients and primary hyperparathyroidism is the most common cause in non-hospitalised patients
What is the most useful test to determine cause of hypercalcaemia? How is it treated?
Most useful test in hypercalcaemia- PTH level
U&Es to confirm, then rehydration with saline, then bisphosphonates if needed
What is the pathophysiology of Hyperosmolar Hyperglycaemic State?
What 3 features are classical? What symptoms would a patient present with?
Hyperglycaemia > osmotic diuresis > vol depletion
1.) Severe hyperglycaemia
2.) Dehydration and renal failure
3.) Mild/absent ketonuria
Extreme dehydration, N+V, ALOC, fatigue
What are the main risk factors for HHS?
Usually elderly pts
New diagnosis of T2DM / poor tx compliance
Infection
High dose steroids
MI
Stroke/ thromboembolism
How do you confirm a diagnosis of HHS? How do you treat?
Diagnosis:
Hypovolaemia
Marked Hyperglycaemia (>30 mmol/L) without significant ketonaemia or acidosis
Tx:
- Give fluids first ( e.g. 0.9% saline over 48hours )
- Replace electrolyte losses
- Gradually normalise blood glucose
Hypothermia, hyporeflexia, bradycardia, confusion and seizures- diagnosis? Tx?
Myxoedemic coma- complication of untreated hypothyroidism
Tx with IV thyroid replacement , IV corticosteroids (until the possibility of coexisting adrenal insufficiency has been excluded) and fluids
Side-effects of thyroxine therapy?
hyperthyroidism: due to over treatment
reduced bone mineral density
worsening of angina
atrial fibrillation
What substances interact with levothyroxine and alter absorption?
Iron / calcium carbonate tablets can reduce the absorption of levothyroxine - should be given 4 hours apart
What is Whipple’s triad?
Suggestive of insulinoma
- Symptoms and signs of hypoglycemia
- Plasma glucose < 2.5 mmol/L
- Reversibility of symptoms on the administration of glucose
C peptide will not fall when insulin administered
Summarise the 3 key types of multiple endocrine neoplasia
MEN type 1: 3 Ps
- Parathyroid: hyperparathyroidism due to parathyroid hyperplasia (most common)
- Pituitary
- Pancreas: e.g. insulinoma, gastrinoma
MEN type 2a: 2 Ps + RET gene
- Parathyroid (60%)
- Phaeochromocytoma
(+ Medullary thyroid cancer)
MEN type 2b : 1 P + RET gene
- Phaeochromocytoma
(+ Medullary thyroid cancer, marfanoid body habitus, neuromas )
What is the course of action for a child with a palpable abdominal mass or unexplained enlarged abdominal organ?
refer very urgently (<48hr) for specialist assessment for neuroblastoma and Wilms’ tumour
raised urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA) levels may be seen
calcification may be seen on abdominal x-ray
Phaeochromocytoma is a rare catecholamine secreting tumour (adrenaline and noradrenaline). How does it typically present?
How do you test for it? How do you manage it?
triad of sweating, headaches, and palpitations in association with severe hypertension
24 hr urinary collection of metanephrines
Surgery is the definitive management. The patient must be stabilized first with medical management:
alpha-blocker (e.g. phenoxybenzamine), then
beta-blocker (e.g. propranolol)
Should thyroid replacement drugs be given at an altered dose in pregnancy?
Yes
Women with hypothyroidism may need to increase their thyroid hormone replacement dose by up to 50% as early as 4-6 weeks of pregnancy due to increased metabolic demand
Primary hyperaldosteronism can present with hypertension, hypernatraemia, and hypokalemia, and maybe also a metabolic alkalosis.
What are the 2 causes?
How are they diagnosed?
How are they treated?
Caused by bilateral adrenal hyperplasia (most common) or Conns (adrenal adenoma) not by excessive stimulation by renin.
Plasma aldosterone:renin ratio is first line investigation
Tx is spironolactone (for BAH) or surgery (Conns)
Symptoms of hypercalcaemia?
“painful bones, renal stones, abdominal groans, and psychic moans,”
Painful bones are the result of abnormal bone remodelling due to overproduction of PTH.
Symptoms of hypocalcaemia?
hyperexcitability of NMJ (bc increases sodium entry into neurones which causes depolarisation) which increases likelihood of AP.
- Pins and needles, tetany, paralysis and convulsions
Depression, nausea, constipation, bone pain →
→ ?primary hyperparathyroidism
How does hyperparathyroidism present?
presents w/ symptoms of hypercalcaemia
raised calcium and PTH and low phopshate on blood tests
pepperpot skull on X-ray
association w/ htn
What is the primary cause of hyperparathyroidism and how is it treated?
Primary cause: solitary adenoma
Definitive tx : parathyroidectomy
- in patients who don’t qualify for surgery cinacalcet can be used - this is a calcimimetic drug that mimics the action of calcium on the parathyroid gland & increases the sensitivity of calcium receptors on parathyroid cells, reducing PTH levels
Excess prolactin can present as impotence, loss of libido, and galactorrhoea in men and amenorrhea and galactorrhea in women. What are the causes?
Causes - the p’s
pregnancy
prolactinoma
physiological
polycystic ovarian syndrome
primary hypothyroidism
phenothiazines, metoclopramide, domperidone
Problems with gliflozins?
They are contraindicated in pts with recurrent thrush bc they increase glucose secreted in the urine
They are also linked to necrotising fasciitis (Fourniere’s gangrene)