endocrine- steroids Flashcards
What are the two parts of the adrenal gland?
The cortex and the medulla
What does the medulla secrete?
Adrenaline
What does the cortex secrete and where?
Zona glomerulosa-Aldosterone
Zona fasicularis-Cortisol
Zona reticularis -Adrenal androgens
What does aldosterone do?
Increases Na+ reabsorption (swaps it for K+)
The increased Na+ absorption increases water absorption.
What drugs inhibit aldosterone?
Angiotensin II blockers- prevent angiotensin II from working.
ACE inhbitors - Inhibit Angiotensin Converting enzyme so less angiotensin II is produced.
What does cortisol do?
Insulin antagonist
Making it difficult to:
- move glucose into the cell.
- generate glucose into other products
- break down glucose that has been stored
Increases blood pressure
Lowers immune system reactivity
Inhibits bone synthesis.
Why is using therapeutic cortisol problematic?
Therapeutic cortisol replaces natural cortisol. This stops ACTH production and causes adrenal gland atrophy.
Therefore, when you come off therapuetic cortisol it has to be done gradually.
What are glucocorticoids?
Insulin antagonsists
e.g. cortisol
What are mineralcorticoids?
These increase salt and water retention causing hypertension.
What is cushing’s syndrome?
When the patient has excess cortisol in the bloodstream.
How do we investigate if a patient has Cushing’s?
24hr urinary Cortisol excretion test
Cushing’s have high result
CRH test
In sufferers Increased CRH Increases ACTH
Dexamethazone supression test
Dexamethazone should inhibit ACTH causing low cortisol
In cushing’s there is high cortisol.
You get the following investigation results.
What has caused them?
ACTH level: HIGH
Cortisol level: HIGH
Pituitary adenoma
Ectopic ACTH production
You get the following investigation results.
What has caused them?
ACTH level: low
Cortisol level: HIGH
Gland adenoma.
What is Conn’s syndrome?
When there is an excess of aldosterone in circulation.
What are the causes of Adrenal hypofunction?
- Problem with the adrenal gland
- Problem with control in the pituitary gland.
What is Sheehan’s syndrome?
When there is a sudden drop of blood pressure.
This stops blood flow to the pituitary gland.
What is Addison’s disease?
Adrenal hypofunction where the patient has low levels of aldosterone and cortisol in circulation. The patient cannot control salt and water levels in the blood.
What investiagations are used to identify Adrenal Hypofunction?
- SynACTHen test
- Do they have a high ACTH level?
You get the following investigation results.
What has caused them?
ACTH level: low
Cortisol level: low
SynACTHen test : positive
Pituitary gland failure
You get the following investigation results.
What has caused them?
ACTH level: high
Cortisol level: low
SynACTHen test : negative
Adrenal gland failure.
ACTH is being produced but the adrenal gland is not responding.
What is hypovolaemic shock?
reduced volume in the blood
What is Hyponatremia?
Reduced sodium level in the blood.
How do we manage a patient with Addison’s disease?
Drugs:
- Cortisol
- Fludrocortisone (like aldosterone)
Steroid prophylaxis
When do you give an Addison’s patient steroid prophylaxis?
- minor Oral surgery
- Spreading of infection of mouth or face
What is Addisonian crisis?
What happens when the patient does not have enough steroids.
They do not have enough cortisol or aldosterone, so do not retain enough salt or water. This causes:
Hypovolaemic shock- reduced volume in blood
Hyponatremia- Reduced sodium in the blood.
Patient gets
- Hypotension
-vomiting
-eventually a coma
How do we manage the addisonian crisis?
Call an ambulance, there is nothing we can do.
A patient is on a dose of Prednisolone >15mg.
How do you cover them?
You don’t need to increase the dose. The patient has enough cover (double the physiological dosage)>
What is the physiological dosage of steroids?
30mg of Hydrocortisone.
The patient is on a dosage of prednisolone of 1-15mg.
How do you cover them?
Give the patient a double oral dosage.
What medical history Q is vital? and why
Have you used systemic steroids in the last 3 months? and why?
We need to know if adrenal gland atrophy has occured & if it has had time to recover.
Atrophy takes 3months. Recovery also takes 3 months.
Your patient has stopped systemic steroids in the last 3 months.
How do you cover them?
100mg IM of hydrocortisone
What can cause oral pigmentation?
Smoking
Racial type
Drugs (e.g. minocycline)
Addison & cushings (not as common)
