Endocrine Emergencies 2 Flashcards
Adrenal Medulla
- Controlled by?
- When stimulated it secretes?
2 Adrenal Cortex
- Three zones: What are they?
- What do they secrete?
Adrenal Medulla
- Controlled by nervous system
- When stimulated secretes epinephrine and norepinephrine into adrenal veins
Adrenal Cortex
- Glomerulosa: mineralocorticoids… aldosterone
- Fasciculata: glucocorticoids… cortisol
- Reticularis: sex hormones
Adrenocorticotropic Hormone ACTH
What does it do?
Primarily what?
Remember, -tropin or -tropic means to stimulate.
Therefore, adrenocorticotropic means “to stimulate the adrenal cortex”
Function: Stimulates synthesis and secretion of adrenocortical hormones (cortisol, androgens, and aldosterone)
ACTH primarily stimulates cortisol
Describe the normal ACTH physiology

What does cortisol stimulate? 4
1) Gluconeogenesis
2) Protein mobilization
3) Fat mobilization
4) Stabilizes lysosomes
Adrenal Insufficiency vs Crisis
- Adrenal Insufficiency is what?
- What kind of disease is this?
- Adrenal Crisis is what?
- What kind of condition is this?
Adrenal Insufficiency
- Failure of adrenal glands to produce essential BASAL secretion of steroids
- Insidious wasting disease
Adrenal Crisis
- Failure to RESPOND to the increased demands caused by stress or SUDDEN INABILITY to secrete essential steroids
- Life-threatening condition
Nova’s likely diagnosis:
Adrenal insufficiency, of which there are two forms:?
- Primary adrenal insufficiency (Addison’s disease)
- Secondary adrenal insufficiency
Adrenal insufficiency?
- Primary adrenal insufficiency (Addison’s disease) results from?
- Secondary adrenal insufficiency results from?
Primary adrenal insufficiency (Addison’s disease)
- Results from destruction or dysfunction of the adrenal cortex
Secondary adrenal insufficiency
- Results from inadequate stimulation of adrenal cortex by ACTH (***By far the most common cause is chronic administration of exogenous steroids!)
Describe how the adrenal pathway changes in primary adrenal insufficiency?

What would happen to the adrenal pathway with exogenous administration of corticosteriods?

Decreased blood pressure?
Decreased cortisol:
- Cortisol up-regulates alpha1-adrenergic receptors on vascular smooth muscle (what does stimulation of the alpha1 receptors do again?) so a decreased amount would…? 3
Decreased aldosterone:
- Aldosterone increases Na reabsorption by renal cells, leading to increases in extracellular fluid volume and blood volume, venous return, cardiac output, and arterial pressure. Therefore a decrease in aldosterone would…? 2
1.
- Cause vasodilation and
- decrease in peripheral vascular resistance
- and decreased BP
2.
- More NA+ to be excreted in the urine and also more water excretion.
- decreased blood pressure
Adrenal Insuffieciency
Pulse rate increase?
Compensatory mechanisms as a result of: 4
- Decreased volume
- With decreased volume we have decreased arterial pressure
- ➔ baroreceptor reflex
- ➔ increased sympathetic outflow and therefore an increase in heart rate
Decreased blood glucose?
Decreased cortisol:
One action of cortisol is to increase blood glucose concentration by promoting gluconeogenesis and decreasing glucose uptake by the tissues and therefore a decrease in cortisol would…?
Decrease blood glucose levels
Hyperkalemia?
Decreased aldosterone:
In addition to stimulating Na reabsorption, aldosterone stimulates K secretion by the renal principal cells and therefore a decrease in aldosterone would…?
inhibit K secretion
Late Distal Tubule/Collecting Duct Area
- The principal cells reabsorb what? 2 And secrete what?
- Aldosterone exerts its effects by increasing the function of the what?

Hyponatremia?
Decreased aldosterone
Aldosterone increases Na reabsorption by renal principal cells. Therefore, with decreased aldosterone we would have…?
Increased Na and water excretion
In contrast to indolent and progressive course of chronic adrenal insufficiency, ***adrenal crisis presents as a life-threatening emergency in which the primary manifestation is what??
hypotension
- When you have a patient that presents with what always consider an adrenal crisis if there is not an immediately apparent cause?
- ***The hypotension in adrenal crisis typically is
resistant to what? 2
- If the missing _______ is not replaced, death will ensue!
- severe hypotension
- catecholamine and IV fluid administration!
- cortisol
Adrenal Crisis
Where is it seen? 4
- In a previously undiagnosed patient with primary adrenal insufficiency who has been subjected to serious infection or other acute, major stress.
- In a patient with known primary adrenal insufficiency who does not take more glucocorticoid during an acute infection (can occur during acute viral infections such as influenza) or other major illness, or has persistent vomiting caused by viral gastroenteritis or other gastrointestinal disorders.
- After bilateral adrenal infarction or bilateral adrenal hemorrhage.
- Rarely in patients with secondary adrenal insufficiency, can be seen in patients withdrawn abruptly from suppressive doses of corticosteroids
Adrenal Crisis
- Presentation? 2
- Dx? 4
- Tx? 2
- Presentation
- Marked hypotension
- Abdominal and flank pain - Diagnosis
- Clinically oriented for abrupt withdrawal from exogenous steroids
- For primary adrenal insufficiency, a short cosyntropin test
(Cosyntropin [ACTH analogue] injected,
- plasma cortisol levels measured in 60 minutes,
- primary adrenal insufficiency excluded if poststimulation level > 550 nmol/L)
3. Treatment - If adrenal crisis suspected or diagnosed, IV glucocorticoids
- D5NS may be required to correct hypovolemia and hypoglycemia
Pheochromocytoma
- What is it?
- The tumor releases what?
- which causes? 5
- reversible?
- Where is the tumor located the majority of the time?
- A tumor derived from neural crest cells of the sympathetic nervous system that is responsible for about 0.1-2% of all cases of hypertension.
- The tumor releases catecholamines
- Which cause episodic (this way most of the time) or sustained signs and symptoms, such as
- palpitations,
- sweating,
- headaches,
- fainting spells, and
- hypertensive emergencies. - A surgically correctable form of HTN!
- Majority of the time tumor located in adrenal medulla
Catecholamines have two major effects, each mediated by a Beta1 receptor. What are they?
- Increased heart rate
- Increased contractility (or force of contraction)
Symptoms can be described by the effects that epinephrine and norepinephrine have on the various organ systems:
Catecholamines have two major effects, each mediated by a Beta1 receptor: How does this affect the blood vessels? 2
- Vasoconstriction of cutaneous blood vessels via Alpha1 receptor
- Vasodilation of skeletal muscle blood vessels via Beta2 receptor
Describe the 90% rule in pheochromocytoma
4
90% tumor (or 10% tumor):
- 90% of the time they arise from the adrenal medulla (with the other 10% they can arise anywhere but the majority occur in the mediastinum or abdomen)
- 90% of the time adrenal pheochromocytoma will be unilateral (otherwise it is bilateral and is likely a genetic syndrome)
- 90% of the time it is not malignant
- 90% of the time it occurs in adults
Keys with pheochromocytoma:
- History is exceptionally important! Symptoms? 4
- Diagnosis is made by? 2
- Once diagnosis is made: Hunt for the source how?
- Pt usually has episodes of
- hypertension,
- headache,
- palpitation, and
- sweating - Demonstrating
- elevated urinary excretion of catecholamines or their metabolites (metanephrines and vanillylmandelic acid)
- DURING a period of hypertension - CT of abdomen with focus on adrenal glands
