Clinical Aspects of the Adrenal Gland Clinical Case & Discussion Flashcards
a
Aldosterone
b
Cortisol
c
Testosterone, Progesterone, Estrogen
d
Norepinephrine, Epinephrine
Name a Mineralocorticoids?
aldosterone
Name a Corticocorticoids
cortisol
Name Sex Steroids
Testosterone, Progesterone, Estrogen
Name adrenal medulla hormones?
Norepinephrine, Epinephrine
WHat are the different types of adrenal disorders that may be present?
What is the common approach to dealing with an adnrela disorder?
Clinical Suspicion
Test for assessing functional status - Is it functioning? Is it primary or secondary?
What is the aetiology?
If tumour: Can it be removed? Is additional Chemotherapy or radiotherapy required? How can we follow the course of the disease?
Endocrine deficiency may need correction
Aetiology specific treatment
What is this image showing?
Hypathalamo Hypopituitary Adrenal axis
how does primary hypofunction affect the hypothalamo hypopituitary adrenal axis
In hypofunction if primary then the adrenal gland is no producing enough cortisol and therefore no feedback so ACTH will rise to try produce more cortisol
If high ACTH then clue it is primary
How are the different hormones made in the different layers of the adrenal gland?
All steroid hormones are derived from cholesterol, but different enzymes are found in different adrenal zones, resulting in different end products e.g. enzymes needed to make aldosterone are found only in the zona glomerulosa
What are the different causes of hypofunction?
Adrenal dysgenesis – doesn’t form and incompatible with life
hyposecretion may be due to Primary Adrenal insufficiency which is caused by what?
Addisons disease
What are the causes of Addison’s disease?
Immune destruction (auto)
Invasion
Infiltration
Infection
Infarction
Iatrogenic
What are the causes of adrenal enzyme defects resuling in hyposecretion
congenital adrenal hyperplasia (most commonly 21-hydroxylase deficiency)
What is Autoimmune Addison’s?
>85% UK cases of adrenal failure
+ve adrenal autoantibodies (to 21-OHase) in 70% cases
lymphocytic infiltrate of adrenal cortex
associated autoimmune diseases are common:
- thyroid disease (20%)
- Type 1 diabetes mellitus (15%)
- premature ovarian failure (15%)
what are common symptoms seen in primary adrenal failure?
Weakness, fatigue, anorexia, weight loss 100%
Skin pigmentation or vitiligo 92%
Hypotension 88%
Unexplained vomiting or diarrhoea 56%
Salt Craving 19 %
Postural symptoms 12%
What are some possible clues to the diagnosis of adrenal failure?
- Disproportion between severity of illness & circulatory collapse/hypotension/dehydration
- Unexplained hypoglycaemia
- Other endocrine features (hypothyroidism, body hair loss, amenorrhoea)
- Previous depression or weight loss
What is the diagnosis of adrenal insufficiency?
Non-specific symptoms - so must think of the diagnosis in the first place!
Routine bloods: U&E, glucose, FBC
Early morning cortisol:
>450 nmol/l (not Addison’s)
<350 nmol/l (adrenal status uncertain)
Synacthen test (and basal ACTH)
If suspicion high & patient unwell, treat with steroids and do Synacthen test later
What is the Short Synacthen test?
The test is based on the measurement of serum cortisol before and after an injection of synthetic ACTH (The function of ACTH is to regulate levels of the steroid hormone cortisol, which released from the adrenal gland)
Summary diagram showing the process of working out if there is an adrenocorticol insufficiency
How is mineralocorticoid replacement carried out?
Synthetic steroid, fludrocortisone
Binds to mineralocorticoid (aldosterone) receptors
50-300 micrograms daily
Adjust dose according to:
- clinical status (postural BP, oedema)
- U&E
- plasma renin level
who needs special care when it comes to stress and steroids?
Hypoadrenal patients on replacement steroids
Patients on steroids in doses sufficient to suppress the pituitary adrenal axis (>7.5mg prednisolone daily, or equivalent)
Patients who have received such treatment during the previous 18/12 (HPA axis may still be suppressed)
what action should be taken in regards to minor short-lived illness or stress?
double glucocorticoid dose
What actions shoudl be taken in regards to major illness or operation?
(especially if nil by mouth or GI upset)
100mg hydrocortisone iv stat
50-100mg HC iv 8-hourly
as stress abates, reduce HC by 50% per day until back on usual replacement dose