Endocrine Flashcards
Jacky, 30, has had a range of persisting symptoms, which doctors believe is down to hypoadrenalism. Which symptom would distinguish between primary adrenal failure and secondary adrenal insufficiency?
Skin hyperpigmentation
Seen in primary adrenal insufficiency (as this will have high ACTH)
Not seen in secondary as this has low ACTH
Hyperpigmentation is caused by melanin stimulating hormone (which has same pre-cursor as ACTH)
Name 4 common features of multiple myeloma
CRAB C- hyperCalcaemia R- Renal failure A - Anaemia (and thrombocytopenia) B - Bone fractures or lytic lesions or bone pain
Investigate: Serum elecrophoresis looking for a monoclonal band
What presenting symptoms and investigation results characterise diabetes insipidus?
Polyuria and polydipsia
High serum osmolality and low urine osmolality
(High urine osmolality would rule out DI)
What steroids are highly mineralocorticoid and which highly glucocorticoid? What side effects do each have?
Mineralocorticoid = Fluid retention, HTN
- Fludrocortisone
Glucocorticoid = Immune suppresion plus all normal steroid SE (endocrine, GI, pysch, cushings etc)
- Dexamethosone
What is indicated by raised ferritin levels?
Either iron overload (10%)
OR
Inflammation (90%) - note ferritin is an acute phase protein
Transferin saturation <50% excludes iron overload
A 41-year-old woman presents with palpitations and heat intolerance. On examination her pulse is 90/min and a small, diffuse goitre is noted which is tender to touch. Thyroid function tests show the following:
Free T4 24 pmol/l
TSH < 0.05 mu/l
What is the most likely diagnosis?
Thyrotoxicosis with tender goitre = subacute (De Quervain’s) thyroiditis
Name 3 ECG changes associated with hyperkalaemia?
Prolonged PR
Wide QRS
Peaked/ tented T waves
What are the three categories and six most common causes of hyponatremia?
Na < 135
Hypovolemic: Diuretics or Addisons
Euvolemic: SIADH
Hypervolemic: Heart/ liver/ renal failure
How do you treat hyponatremia in acute and chronic situations?
PLUS TREAT UNDERLYING CAUSE Acute (<48hrs) = 3% hypertonic saline Chronic: - Hypovolemic = 0.9% isotonic saline - Euvolemic = Fluid restriction - Hypervolemic = Fluid restriction (plus furosemide if underlying condition warrants it)
What are the symptoms of hyponatremia? (5)
Confusion, headache, balance difficulty Altered mental status Seizures/ coma Orthostatic hypotension Low urine output, decreased JVP, dry mucus membranes, poor skin turgor
What are the most common causes of hypernatremia? (5)
Water loss
- Hyperglycemia
- Loop diuretics
- Diabetes insipidus (not enough ADH to reabsorb water)
- Severe diarrhoea, sweating, burns, vomitting etc
Not enough water gain
- Limited intake of water
Sodium gain
- Cushings (= increased glucose, sodium retention with the water retention)
- Primary aldosteronism (resets regulation of ADH secretion)
How do you manage hypernatremia?
Oral or IV fluids
Plus treat underlying cause
- If water loss may need desmopression (Diabetes insipidus)
- If excess sodium and fluid overload may need loop diuretic
What are the definitions of hyperkalaemia?
Mild - 5.5-5.9 mmol/L.
Moderate - 6.0-6.4 mmol/L.
Severe - >6.5 mmol/L.
What are the main causes of hyperkalaemia? (4 groups)
DRISP
Drugs (ACEI, ARBs, NSAIDS, heparin)
Renal (AKI/ CKD/ addisons)
Increase in production (Tumour lysis syndrome, trauma, burns)
Shift from intracellular to extracellular (DKA)
Pseudo (long tourniquet time, clenched fist, test tube haemolysis)
Name 3 symptoms of hyperkalaemia?
Usually non specific weakness and fatigue
Can get muscle paralysis, SOB and bradycardia
What investigations should be done on a patient with hyperkalaemia? (4)
Repeat K+ ECG Glucose FBC ABG
Name 3 changes on an ECG associated with hyperkalaemia?
Peaked T waves Prolonger PR (>200) Wide QRS (>120)
Hyperkalaemia can cause conduction disturbances!
How should hyperkalaemia be managed is K+ is 7.1?
SEVERE: Urgent ABCDE
- ABG to give immediate determination if true result, perform ECG
1) 10ml 10% Calcium gluconate to protect heart (works in 1-3mins, lasts 30-60mins). Keep giving upto 50ml until ECG improvement
2a) Insulin-glucose infusion (10units with 25g glucose) - moves K+ into cells. NB: K+ should come down 0.5-1 over 15mins
2b) Nebulised salbutamol (10-20mg should reduce K+ 0.5-1mmol/L in 15-30mins)
How should a K+ of 5.9 be treated?
Use calcium resonium (gets K+ out of GI tract, brings down by approx 1mmol but takes 2 hours so no use in acute setting)
How is hypokalaemia classified?
Mild - 3.1-3.5 mmol/L
Moderate - 2.5-3.0 mmol/L
Severe - <2.5 mmol/L
What are the three most common causes of hypokalaemia?
Increased water loss: - Diuretics - Vomiting/ diarrhoea Cellular shift: - Alkalosis - Insulin/ glucose Decreased K+ intake: - NBM - Anorexia
How does hypokalaemia present?
Generally asymptomatic
Can give weakness, muscle pain, constipation or paralysis
What are the findings in an ECG for a patient with a K+ of 2.9?
ECG changes in hypokalaemia:
- Flat T waves
- ST depression
- Prominant U waves
How is hypokalaemia managed? (2)
If mild: Dietary suppliments (40-120mmol/day)
If secondary care and severe:
- IV KCL (never bolus, give with normal saline). Needs careful monitoring
You are called to the ward to see a patient with high sugars, roughly how much does 1 unit of insulin cause a BM to drop?
1 unit drops blood glucose by approx 3mmol
Remember aiming around 8-10
Name 3 rapid acting insulins? When are they used?
Humalog
Novorapid
Apidra
Fiasp
All act rapidly (within 20mins) and have short action (<6hours)
Good for meal time insulin and correcting insulin
When should biphasic insulins be given?
At meal times
As contain rapid and intermediate acting insulins
What is the definition of hypoglycaemia?
Under 3mmol however in practice any under 4 should be treated
What is a phaeochromocytoma and how does it present?
Neuroendocrine tumor of the medulla of the adrenal glands
Present: Raised BP, palpitations, sweating, anxiety
What investigation is done for phaeocrhomocytoma?
24 hr urinary metanephrines
What is the treatment pathway for phaeochromocytoma?
A- Alpha blocker
B- Beta blocker
C- Cut it out (surgery)
How does congenital adrenal hyperplasia present and what is the most common cause?
Kid with precocious puberty and possible sex changes
Due to 21-hydroxylase deficiency
What investigation should be done for congenital adrenal hyperplasia?
17-hydroxyprogesterone
What is the function of vasopressin?
Vasopressin = ADH
Causes retention of water (solute free)
What is diabetes insipidus and how can causes be categorised?
Diabetes insipidus = not enough ADH (so no stopping of diuresis = lots of diuresis)
Therefore presents with polyuria and polydipsia
Cranial cause - Not producing ADH in post pituitary
Renal cause - Not responding to ADH
What is seen on plasma and urine osmolarity in diabetes insipidus?
Plasma osmolality = High
Urine osmolality = Low (as lots of fluid in urine so it’s dilute)
What is the first/ second line investigation of diabetes insipidus?
1) Water deprivation test
Would expect urine osmolality to rise, if it DOESN’T then this is DI (if it does probably pyschogenic cause of polydipsia)
2) Desmopressin test
- Giving ADH should put things back to normal (raised urine osmolarity). If it does then this is pituitary cause of the DI, if it doesn’t the kidneys aren’t responding to any ADH so renal cause
How do you manage diabetes insipidus?
Cranial cause = Give desmopression (ADH)
Renal cause = Supportive, protect kidneys, desmopression may help a bit
What is the action of aldosterone?
Promotes water reabsorbtion (via Na+ absorbtion and K+ excretion)
- So spironolactone which inhibits aldosterone causes less reabsorbtion (lowerBP) and less K+ excretion (which is why can cause hyperkalaemia)
What are the features of acromegaly (increased growth hormone 2ndry to pituitary adenoma)
Spade hands, increase show size
Large tongue
Excessive sweating and oily skin
Pituitary tumour > Headaches, bitemporal hamianopia