Adrenal Flashcards
1
Q
Where are the adrenal glands located?
A
atop the kidneys
2
Q
What are the adrenal glands also called?
A
suprarenal glands
3
Q
What shape are the adrenal glands?
A
triangular or semilunar shaped
4
Q
T/F: adrenal glands contain distinct zones which produce different hormones
A
True
5
Q
What type of hormones are the adrenal glands responsible for releasing?
A
Stress hormones
6
Q
A/P: The adrenal gland has both a _____ & _____
A
cortex and a medulla
7
Q
What does cortex mean?
What does medulla mean?
A
outer layer
inner region
8
Q
*** The adrenal medulla is connected directly to the sympathetic nervous system via
A
nerves
9
Q
What does the adrenal medulla bridge?
A
bridges the endocrine and sympathetic nervous system
10
Q
The adrenal medulla releases substances known as ________ which enter the circulation and act on ________ like other hormones
A
catecholamines
distal tissues
11
Q
What are catecholamines made by?
A
Catecholamines are made by chromaffin cells in the adrenal medulla
12
Q
What are all catecholamines derived from?
A
tyrosine
13
Q
*** What are the 4 catecholamines?
A
DOPA, Dopamine, Norepinephrine, and Epinephrine
14
Q
What do catecholamines activate?
A
the stress or “fight or flight” response
15
Q
What is the principle product of the adrenal medulla?
A
epinephrine
16
Q
Where is epinephrine made?
A
Epinephrine is made ONLY in the adrenal medulla
17
Q
What percentage of epi and norepinephrine are made in the adrenal medulla?
A
Epi accounts for 80%
Norepi accounts for 20%
Scant amount of dopamine also made here
18
Q
What does the fight or flight response demonstrate control of?
A
adrenal medullary function
19
Q
Epi and norepi are released and act as hormones causing
A
sympathetic activation
20
Q
Sympathetic activation is a mobilization of needed resources including
A
increased blood pressure, heart rate, blood glucose, and brochodilation
Dowshifting of less needed resources also occurs.
21
Q
What is the F or F response activated by?
A
pain, fear, hemorrhage, cold, hypoglycemia, hypotension, heat, exercise
22
Q
What does the F or F response increase CO to?
A
heart and skeletal muscle
23
Q
What does the F or F response decrease CO to?
A
kidneys, skin and mucosa
24
Q
What does the F or F response mobilize for energy?
A
glucose and fatty acid
25
Is respiration increased or decreased d/t F or F?
increased
26
T/F: Epinephrine and norepineprine are similar but differ in important ways
true
Differences occur in which adrenergic receptors they stimulate
27
Epinenephrine and Norepinephrine both have ______ effects which result in arterial _______
strong alpha-1
vasoconstriction
28
Which catecholamine has a stronger beta 1 effect?
Epinephrine has stronger beta-1 effects which increases heart rate and contractility more
29
*** What enzyme is necessary for the conversion of norepinephrine to epi?
Phenylethanolamine N-Methyltransferase (PNMT)
30
*** What is PNMT expression regulated by?
glucocorticoids (cortisone), which helps to account for glucocorticoids role in affecting blood pressure
31
What is pheochromocytoma?
a tumor either caused by adrenal medullary hyperplasia or extra-adrenal chromaffin tissue
32
How does a pheochromocytoma tumor effect catecholamines?
These tumors make catecholamines in an unregulated fashion.
33
*** What are symptoms of pheochromocytoma?
paroxysmal hypertension, tachycardia, headache, sweating, anxiety, tremor, and glucose intolerance
34
How are most pheochromocytoma tumors localized?
Most tumors (85-90%) are solitary tumors localized to a single adrenal gland (mostly the right)
35
Where are 10% of pheochromocytoma tumors located?
10% of tumors are extra-medullary, of these 95% are in the abdomen
36
How is pheochromocytoma diagnosed?
Diagnosis is made with first a strong clinical suspicion based on symptoms, then through biochemical testing, then imaging
37
What lab helps make a diagnosis of pheochromocytoma and how?
Urinary Vanillylmandelic acid (VMA) levels help to make the diagnosis as both epinephrine and norepinephrine are degraded to this
38
what type of imaging is useful for diagnosis of a pheochromocytoma tumor?
Ultrasound and MRI are useful in locating tumors and have decreased need for surgical localization
39
T/F: Anesthetic considerations have helped decrease perioperative mortality from a high of 45% to 0-3%
true
40
The introduction of __________ preoperatively reduces the incidence of periop blood pressure fluctuations, MI, CHF, dysrhythmias, and CVA
alpha adrengergic antagonist
41
The alpha blockers _____ or _____ should be started 10-14 days prior to surgery to normalize BP
phenoxybenzamine or prazosin
42
For pheochromocytoma, what type of blockade must happen first?
Once adequate alpha blockade is established, beta blockade can begin
Beta blockade is delayed because of the risk of unopposed alpha mediated vasoconstriction
43
For pheochromocytoma, when arteries do relax after alpha and beta blockade - what will they need?
volume expansion
44
What does the typical anesthetic plan for pheochromocytoma include?
typically includes GETA with arterial line, and central venous access
45
Why are short acting agents desired during pheochromocytoma surgery?
paroxysms of both hypotension and hypertension are common when the tumor is manipulated or removed
46
What agents should be AVOIDED in pheochromocytoma surgery?
Avoidance of histamine releasing agents, metoclopramide, and glucagon (these agents provoke pheochromocytomas)
47
What my happen when the pheochromocytoma tumor is removed?
abrupt hypotension
48
What is the initial treatment for abrupt hypotension after the pheochromocytoma is removed?
Restitution of intravascular fluid deficits is initial treatment, but vasopressors are sometimes needed
49
When do catecholamine levels return to normal after pheochromocytoma surgery?
When does BP return to normal?
Catecholamine levels return to normal several days after surgery and approximately 75% of patients become normotensive within 10 days postop
50
Is medullary hypo secretion a serious problem?
NO
the sympathetic nervous system compensates for cardiovascular regulation
other regulatory hormones compensate for metabolic effects
51
The adrenal cortex mediates the stress response via the production of substances known as _______ & _______, it also is a secondary site of _______ synthesis
mineralocorticoids and glucocorticoids
androgen
52
How many zones is the adrenal cortex divided into? What are they?
3
the zona glomerulosa
the zona fasciculata
the zona reticularis
53
*** What does the zone glomerulosa produce?
mineralocorticoids
54
*** What does the zone fasiculata produce?
glucocorticoids
55
*** What does the zone reticularis produce?
androgens
56
*** What is the primary mineralocorticoid produced?
aldosterone
57
*** What is the primary glucocorticoid produced?
cortisol
58
*** What is the primary androgen produced?
androstenedione
59
*** All of these are STEROID HORMONES (aldosterone, cortisol, androstenedione), and ALL are synthesized from ______
cholesterol
60
Why are mineralocorticoids named so?
because they control “minerals” also known as the electrolytes sodium (Na+) and potassium (K+)
61
*** What is the primary mineralocorticoid?
aldosterone
62
How does aldosterone work?
Aldosterone effects salt and water balance and thereby effect long term regulation of blood pressure
63
What part of the kidney does aldosterone effect?
distal convoluted tubule and collecting ducts of the kidneys
64
What does aldosterone cause retention and excretion of?
causes retention of sodium and water and excretion of potassium and hydrogen
65
*** aldosterone is unopposed, what does it lead to?
If unopposed, aldosterone leads to hypertension, extracellular fluid expansion, hypokalemia, and alkalosis
66
What does aldosterone work with for BP control?
renin-angiotensin system
67
Briefly describe the RAAS
Hypovolemia triggers kidneys to secrete renin
Through a series of steps angiotensin II is produced
Angiotensin II is a potent vasoconstrictor and also stimulates the secretion of aldosterone
Aldosterone causes retention of water and sodium and secretion of potassium, and also increases blood pressure
68
What is aldosterone primarily regulated by?
Aldosterone is regulated primarily by renin-angiotensin system and by potassium levels
69
Do adrenalcorticotropic Hormone (ACTH) and sodium levels exert much control over the release of aldosterone
NO
70
*** What is primary hyperaldosteronism also known as?
Conns syndrome
71
*** What is Conns Syndrome caused by?
Caused by aldosterone secreting tumors or hyperplasias
72
*** What are the effects of Conns Syndrome?
increased ECF volume, hypertension, K+ depletion and metabolic alkalosis
73
*** What is the diagnosis and treatment for Conns Syndrome?
Low Renin from negative feedback
Surgical
74
What is the term for adrenal insufficiency?
hypoaldosteronism
75
What happens with Na and K in hypoaldosteronism?
Na is lost in urine, K is retained
Plasma volume decreases and hypotension/ hyperkalemia may lead to circulatory collapse
76
How did glucocorticoids get their name?
because of there effects on glucose metabolism
77
What is another name for cortisol
hydrocortisone (they are the same thing!)
78
*** What is the principle glucocorticoid and where is it produced?
Cortisol is the principal glucocorticoid and is produced in the zona fasciculata
79
Cortisol is essential for life, and regulates a variety of what type of functions functions
cardiovascular, metabolic, immunologic, and homeostatic
80
What does glucocorticoids stimulate?
Gluconeogenesis
81
What is gluconeogenesis?
Formation of carbohydrate from protein by the liver
Causes mobilization of amino acids from muscle
82
What happens to muscles in great cortisol excess?
muscle weakness
83
Does glucocorticoids increase or decrease glucose utilization by cells
decrease
84
Does glucocorticoids increase or decrease blood glucose levels?
increase
Caused by both increased formation of glucose by the liver and decreased utilization of glucose by tissue
85
Almost any stress (physical or neurogenic) can cause an immediate release of ____ by the _______ gland followed by greatly increased secretion of cortisol
- Trauma
- Infection
- Heat/Cold
- Surgery
- Catecholamine injection
ACTH
ANTERIOR pituitary
Unclear what benefit cortisol provides in stressful situations, probably related to mobilization of resources for immediate availability
86
High levels of cortisol have what type of effect?
anti-inflammatory effects
87
How does cortisol prevent development of inflammation?
by stabilizing lysosomes, decreasing capillary permeability, decreasing migration of WBC’s into inflamed areas, and other effects
88
Cortisol also causes resolution of inflammation within what time frame?
hours to days
Mechanism unclear
May be due to mobilization of energy resources for quicker repair
May be due to inactivation and removal of inflammatory products
Healing is enhanced
Useful in autoimmune processes, allergic reactions
89
What stimulates cortisol secretion?
Adrenocorticotropic Hormone (ACTH) stimulates cortisol secretion almost entirely
90
What is ACTH controlled by? and where does it come from?
ACTH release is controlled by Corticotropin-Releasing Factor (CRH) from the hypothalamus.
91
What causes a release of both ACTH and CRH?
physiologic stress
92
What causes inhibition of ACTH and CRH release
High levels of cortisol
93
Cortisol release is caused by the _____ when it senses stress
Cortisol helps relieve the damaging nature of the stressful state
Cortisol provides direct _______ to decrease its release
hypothalamus
negative feedback
94
CRH, ACTH, and cortisol are released in relation to _________ with high levels in the morning
circadian rhythms
95
What is Cushings DISEASE
ACTH secreting tumor of the pituitary
96
What is Cushings SYNDROME?
caused by excessive cortisol secretion
97
What are 4 ways Cushing Syndrome can happen?
ACTH secreting ectopic tumor
Overactive Hypothalamic secretion of CRH
Primary glucocorticoid secreting adrenal tumor
Iatrogenic (chronic administration)
98
What happens to bone and muscle in Cushings Syndrome?
osteoporosis
Muscle wasting, weakness, fatigability
(These are the ones he specifically went over - look at slide 33!)
99
Cushing Syndrome: Fat changes
Truncal obesity, moon facies, buffalo hump
100
Cushing Syndrome: Renal changes
Salt/ water retention, HYPOkalemia from mineralocorticoid activity of excess glucocorticoids
101
Cushing Syndrome: CV
hypertension
102
Cushing Syndrome: Endocrine
Impaired glucose tolerance, amenorrhea
103
What does Addisons disease result from?
Results from failure to produce adrenocortical hormones (glucocorticoids and mineralocorticoids)
104
What is primary Addisons disease?
Adrenal nonfunction-mostly autoimmune
105
What is secondary Addisons disease?
Hypothalamic or pituitary nonfunction
106
What are causes of secondary Addisons disease?
Adrenal atrophy, metastatic tumor, TB, Iatrogenic/acute withdrawal of glucocorticoid treatment or removal of cortisol secreting tumor
107
What are symptoms are glucocorticoid deficiency?
Hypoglycemia, fatigue, weakness, weight loss, anorexia
Hyperpigmentation (primarily by increased ACTH)
Severe deterioration to stress
108
How do you treat an Addisonian Crisis?
treat crisis with cortisol
109
symptoms of mineralocorticoid deficiency
```
Dehydration
Polyuria
Hypotension
Low Na+
Retention of K+
Metabolic acidosis
```
110
In what time frame will death occur if Addisonian Crisis is not treated?
Death in 4 days to 2 weeks if untreated
111
How do you treat an Addisons Disease?
Treat with glucocorticoids and mineralocorticoids (need both)
112
What can happen to a patient who takes chronic steroids when these medications where held periop?
Case reports of patients who take chronic steroids having periop shock or death when these medicines were held, presumably from acute adenal insufficiency
113
Are larger or smaller doses of glucocorticoids given to patients in the periop period who have Addisons?
larger
Little evidence to support definitive guidelines for who, when, and how much to give
oftentimes hydrocortisone 50-100mg IV given to adult patients
114
*** Why should you NOT use etomidate in this patient population?
Etomidate causes profound suppression of cortisol for at least 24 hours and can contribute to adrenal insufficiency and resultant hypotension
Etomidate should be used sparingly (or never) in patients with septic shock for this reason
115
T/F: Etomidate has not been shown to increase mortality when used for rapid sequence induction
True
