endocrinology Flashcards
What is Addisons disease ?
autoimmune destruction of the adrenal gland
results in reduced cortisol and aldosterone being produced.
Features of Addisons disease?
lethargy
weakness
anorexia
N&V
Weight loss
Salt craving
Hyperpigmentation
Vitiligo
Loss of pubic hair in woman
Hypotension
Hypoglycaemia
Hyponatraemia and hyperkalaemia
Crisis - collapse, shock, pyrexia
Causes of hypoadrenalism
primary causes
tuberculosis
metastases (e.g. bronchial carcinoma)
meningococcal septicaemia (Waterhouse-Friderichsen syndrome)
HIV
antiphospholipid syndrome
Secondary causes
pituitary disorders (e.g. tumours, irradiation, infiltration)
Exogenous glucocorticoid therapy
Addisons disease management?
Give a glucocorticoid and a mineralocorticoid
This usually means that patients take a combination of:
hydrocortisone: usually given in 2 or 3 divided doses. Patients typically require 20-30 mg per day, with the majority given in the first half of the day
fludrocortisone
patient education with Addisons?
emphasise the importance of not missing glucocorticoid doses
consider MedicAlert bracelets and steroid cards
patients should be provided with hydrocortisone for injection with needles and syringes to treat an adrenal crisis
discuss how to adjust the glucocorticoid dose during an intercurrent illness (see below)
Management of Addisons with intercurrent illness?
in simple terms the glucocorticoid dose should be doubled, with the fludrocortisone dose staying the same
Adrenal Crisis?
Adrenal crisis: An acute life-threatening condition characterized by severe hypotension, hypoglycemia, and altered mental status. Immediate treatment with intravenous hydrocortisone, fluids, and electrolyte correction is crucial.
Differentials for Addison’s disease?
Adrenal Insufficiency Secondary to Pituitary Disease
Adrenal Tuberculosis
Sepsis
Management of adrenal crisis
IV or IM hydrocortisone immediately
Patients should go to hospital immediately
1L of NaCl over 30 minutes
Monitor BP, HR, electrolyte and glucose status
IV hydrocortisone - infusion or QDS until patient is haemodynamically stable
Offer at least 40 mg oral hydrocortisone daily in 2 to 4 divided doses or at least 10 mg oral prednisolone daily in 1 to 2 divided doses until any underlying cause has resolved and the person is clinically stable.
ECG findings in hyperkalaemia?
ypical ECG findings include peaked T waves, flattened P waves, prolonged PR interval, widened QRS complex and sine wave pattern in severe cases
causes of hyperkalaemia ?
AKI
CKS
Addisons
Congenital adrenal hyperplasia
potassium sparing duretics
ACEi
Acidosis
Tumour Lysis syndrome
Rhabdo
what is considered hypoglycaemia?
BM < 3.3
causes of hypoglycaemia?
Diabetes (excess insulin, sulfonylureas) more likely to occur in diabetes who have a viral illness, have drunk alcohol or exercised more than usual, or just changed dose of a new medication
Non-diabetic causes
indomethacin, pentamidine, quinine, sulfonamide, IGF-1 and lithium.
Alcohol consumption
This is due to its inhibitory effect on gluconeogenesis and glycogenolysis.
Rarer causes:
hypopituitarism and Addisons disease
Insulinoma
what is the normal response when blood glucose drops?
The initial response to declining blood glucose involves the autonomic nervous system and counter-regulatory hormones. As glucose levels drop, the pancreas reduces insulin secretion, which normally facilitates cellular uptake of glucose. Concurrently, there is an increase in glucagon release from pancreatic alpha cells. Glucagon promotes glycogenolysis and gluconeogenesis in the liver, elevating plasma glucose concentrations.
Adrenaline (epinephrine) is also released from the adrenal medulla, stimulating hepatic glycogenolysis and inhibiting insulin release further. This hormone additionally activates lipolysis in adipose tissue, providing free fatty acids as an alternative energy source for peripheral tissues, thereby sparing glucose for cerebral use.
Cortisol and growth hormone are secreted in response to prolonged hypoglycaemia. Cortisol enhances gluconeogenesis and decreases peripheral utilisation of glucose by antagonising insulin action at target tissues. Growth hormone similarly supports gluconeogenesis while promoting lipolysis.
why do patients get symptoms when they are hypoglycaemic?
The symptoms of hypoglycaemia can be attributed to neuroglycopenia and autonomic activation. Neuroglycopenic symptoms arise due to insufficient glucose supply to the brain, manifesting as confusion, altered consciousness, seizures or even coma if untreated. Autonomic symptoms such as tremors, palpitations and sweating are mediated by adrenaline release.
