Endocrinology Flashcards
HbA1c 86 mmol/mol (10.0%). What is the average glucose?
Average glucose = (HbA1c, % x 2) - 4.5 Average glucose = 15.5
45F, Lethargy, Na 129, K 5.1, Total T4 66 (RR 70-140). Next Ix?
Short synacthen test Addison’s: Fatigue, Low Na, High K May be associated with hypothyroidism Hypothyroidism would not cause high K
Abdo pain, vomiting, Hypotensive, Hypoglycaemia, PMHx Hypothyroidism. Tx?
Dx: Addison’s Tx: Hydrocortisone Addison’s is associated with Hypothyroidism
Causes of hypokalaemia with hypertension (4)
Causes of hypokalaemia with normal BP (5)
Hypokalaemia with hypertension
- Cushing’s syndrome
- Conn’s syndrome (primary hyperaldosteronism)
- Liddle’s syndrome
- 11-beta hydroxylase deficiency
Hypokalaemia without hypertension
- Diuretics
- GI loss (e.g. Diarrhoea, vomiting)
- renal tubular acidosis (type 1 and 2)
- Bartter’s syndrome
- Gitelman syndrome
Heavy periods + Polycythaemia. Dx?
Uterine fibroids
Osmolality formula
Estimated osmolality = 2 (Na + K) + Urea + Glucose
Ix for GH deficiency
Insulin
Hypoglycaemia is a potent stimulus for GH release
Ix for Acromegaly
Initial Ix?
Definitive Ix?
Serum IGF-1: ↑ [initial Ix]
OGTT [confirm diagnosis]
- If Normal: Glucose load –> ↓ GH levels
- If Acromegaly: Glucose load –> Paradoxical ↑ GH levels
Tx for Acromegaly
(1st line) Trans-sphenoidal surgery
(2) Somatostatin analogue (Octreotide)
(2) Dopamine agonist (Cabergoline, Bromocriptine)
(3) GH receptor antagonist (Pegvisomant)
Causes of hyperprolactinaemia
Pregnancy
Prolactinoma
Pituitary adenoma (stalk compression)
Acromegaly (high GH has prolactin like effects)
Primary hypothyroidism (high TRH)
Dopamine receptor antagonists
Tx for prolactinoma
(1) Dopamine agonist (Cabergoline, Bromocriptine)
(2) Trans-sphenoidal surgery
Raised serum osmolality, Low urine osmolality
Diagnosis?
Ix?
Treatment?
Diabetes insipidus
Ix: Fluid deprivation + DDAVP test
If cranial DI –> Desmopressin
If nephrogenic DI –> Thiazide diuretic (Bendoflumethiazide)
Low plasma osmolality, Raised urine osmolality
Diagnosis? Treatment?
SIADH
Treat underlying cause
Fluid restriction
+/- Lithium +/- Demeclocycline +/- Tolvaptan
Known pituitary tumour
Acute onset headache
N&V
Xanthochromia
Diagnosis? Tx?
Pituitary apoplexy (haemorrhage of pitutiary tumour)
Tx:
(1) IV Hydrocortisone (given first)
(2) Levothyroxine
+ Surgical intervention
Tx of acute thyroid storm
- High-dose anti-thyroid drug (Carbimazole, Propylthiouracil, Methimazole)
- + Corticosteroids
- β-blockers (IV Propanolol)
- Iodine (Lugol solution)
Hashimoto’s thyroiditis
Associated with
Hashimoto’s thyroiditis
Associated with
- Other autoimmune diseases
- MALT Lymphoma
Pendred’s syndrome
Clinical features? Cause?
Pendred’s syndrome
Autosomal recessive –> defect in organification of iodine
- Progressive hearing loss
- Hypothyroidism
- Goitre
- MRI: one ond a half turns of cochlea
Middle-aged woman
Hypothyroidism
“woody” goitre
Diagnosis?
Riedel’s thyroiditis = thyroid is replaced by fibrotic tissue
Adrenal zones
Ix for Cushin’s syndrome
Low dose dexamethasone suppression test:
diagnostic [GOLD STANDARD] [1st line]
Tx for Cushing’s syndrome
Medical
- Metyrapone (S/E: Hyperaldosteronism, Hirsuitism)
- Ketoconazole (S/E: Hepatotoxic)
Surgical
- If Cushing’s disease –> Pituitary surgery (Transsphenoidal hypophysectomy)
- If Ectopic ACTH production –> removal of tumour
- If Adrenal adenoma –> Unilateral (or Bilateral) adrenalectomy
Hypertension + Hypokalaemia
Diagnosis? Ix? Tx?
Hyperaldosteronism
- Bilateral adrenocortical hyperplasia (2/3) –> most common
- Conn’s syndrome (1/3) = aldosterone-producing adenoma
Ix: Plasma Aldosterone : Renin ratio
Tx:
- Short term –> MR antagonists (Spironolactone / Epleronone)
- Long term –> Laparoscopic adrenalectomy (both NOT both!)
Ix for Phaeochromocytoma
24 hour urinary metanephrines: raised
Hyponatraemia + Hyperkalaemia
Diagnosis? Ix?
Addison’s disease
SynACTHen test