Endocrine (Altose): Adrenals and Pituitary

Question 1

What are two classes of hormones that the adrenal Cx releases?

Give one example of each (that we went over)

Answer 1

Mineralocorticoids (Aldosterone)

Glucocorticoids (Cortisol)

Question 2

Describe the pathway of Aldosterone release.

Answer 2

Renin (kidney) –> Angiotensin I (liver) –> ACE lung –> Angiotensin II

Angiotensin II + serum K –> Aldosterone release (adrenal Cx)

Question 3

What are the effects of aldosterone?

Answer 3

Save Sodium, Pee Potassium

(Na retention, K excretion)

Question 4

What os Conn’s Syndrome?

Answer 4

Hyperaldosteronism due to adenoma

Question 5

What are some symptoms of hyperaldosteronism?

Answer 5

HTN

HypoK metabolic alkalosis

Weakness

Fatigue

Question 6

How can we treat hyperaldosteronism?

Answer 6

Treatment for Conn’s syndrome:

Replace potassium (0.5 mg/kg/hr central line; 4x slower in peripheral IV due to venal irritation)

Sx removal of adenoma

Note: If K > 2.8, cancel non-related elective case! (low serum potassium reflects much larger deficit since K is usally mostly sequestered in cells)

Question 7

What are some symptoms of hypoaldosteronism?

Answer 7

HoTN, Severe hyperK, metabolic acidosis

Question 8

How can we treat hypoaldosteronism?

Answer 8

Administer fludrocortisone

Question 9

Describe the pathway to cortisol release.

Answer 9

CRF (hypothalamus) –> ACTH (ant pituitary) –> Cortisol (adrenal Cx)

CRF: corticotropin releasing factor

ACTH: adrenal corticotropic hormone

Question 10

According to Dr. Altose, would a year of 5 mg prednisone overpower the body’s ability to make sufficient cortisol for surgical stress?

What is the threshold for stress dose administration with prednisone intake?

Answer 10

A year of 5 mg of prednisone should not overpower body’s adrenal gland’s ability to make sufficient cortisol even if taken over a year - this is because body produces 20 mg/day of cortisol normally and can produce up to 300 mg a day under stress.

HOWEVER, 20 mg of prednisone over 5 days can seriously impair the body’s ability to respond to surgical stress for up to 9-12 months (length of time to recover full adrenal cx function)!

Question 11

What are the effects of cortisol on your body?

Answer 11

Increases blood glucose

Catabolic reactions (breakdown)

Anti-inflammatory

Anti-immune

Question 12

Why does Cushing’s syndrome develop?

Answer 12

Develops due to chronic high levels of cortisol due to the intake of oral glucocorticoids/steroids.

Question 13

What are some signs of Cushing’s syndrome?

Answer 13

Truncal obesity

Buffalo hump

Abdominal striae

Hyperglycemia

Osteopenia

HTN

Volume overload

Hypokalemic metabolic alkalosis (hyperaldosteronism)

Immunosuppression

PUD

Emotional changes

Question 14

What is Addison’s diseases?

Answer 14

Disease state of adrenal insufficiency

Question 15

How should we manage Cushing’s syndrome intraoperatively?

Answer 15

Manage HTN

Monitor volume status

Careful with bones

Watch for Addisonian crisis (acute adrenal insufficiency that can occur as a rebound)

Question 16

What are some primary causes of adrenal insufficiency/Addison’s disease?

Answer 16

Idiopathic

Autoimmune

Infection

Question 17

What are secondary causes of adrenal insufficiency?

Answer 17

HPA suppression

HypoACTH

Question 18

What is our primary intra-op concern with adrenal insufficiency?

Answer 18

HoTN

Question 19

How is Addison’s disease diagnosed?

Answer 19

Serum cortisol < 18 mcg/dL

Increase of < 9 mcg/dL after admin of 250 mcg ACTH

Question 20

During acute stress, a normal pt’s plasma cortisol should be.. (#)

Answer 20

>22 mcg/dL

Question 21

25 mg of cortisol is equivalent to how much hydrocortisone?

Prednisone?

Decadron?

Fludrocortisone?

Answer 21

20 mg Hydrocortisone

5 mg Prednisone

0.75 mg Decadron

2 mg Fludrocortisone (use to treat hypoaldosteronism)

Question 22

What is the primary precursor for all catecholamines?

Answer 22

Tyrosine

Question 23

What is the rate limiting step in catecholamine production?

Answer 23

Tyrosine hydroxylase

Tyrosine –> Tyrosine hydroxylase+Tyrosine –> DOPA

Question 24

What are the roles of COMT and MAO?

Answer 24

Enzymes that breakdown catecholamines into metanephrine, nor-metanephrine, and vanillylmandelic acid

Question 25

How is pheochromocytoma traditionally diagnosed?

Answer 25

Look for catecholaminergic breakdown products in the urine (metanephrine, normetanephrine, vanillylmandelic acid)

Question 26

What are the symptoms of pheochromocytoma?

Answer 26

HTN Palpitations Tremor Sweating (Similar to MH and Thyroid Storm)

Question 27

How do we pre-operatively manage a pt that has pheochromocytoma?

Answer 27

Alpha block first (phentolamine, phenoxybenzamine, prazosin) Beta block second

Question 28

When managing a pt with pheochromocytoma, why must we give alpha blockers before beta blockers?

Answer 28

Beta blockers decrease CO via negative inotropy, etc.. Alpha blocks will drop BP Drop in BP may be too much for the beta-blocked heart to handle, which may result in heart failure. This is why we drop BP / alpha block first, so that we can titrate in beta blockers to the point where CO is still maintained.

Question 29

What pressors should we avoid, if we can, in pts with pheochromocytoma?

Answer 29

Ephedrine (due to its indirect mechanism of action, it's difficult to maintain tighter control of Norepi levels)

Question 30

What is the goal of pre-op preparation for a pt with pheochromocytoma?

Answer 30

BP management Volume expansion This can take ~2 weeks

Question 31

In patients with pheo, what are some intra-op considerations? (monitors, drugs)

Answer 31

A-lines CVP (potential for big boluses and infusions) Avoid halothane (increases epi, may cause arrhythmias) Phenylephrine \> ephedrine for HoTN NTG, SNP, nicardipine, Ca-channel blockers for HTN Avoid histamine release

Question 32

What are post-op complications after removal of an adrenal mass for a pheochromocytoma pt?

Answer 32

Rebound HoTN Renal injury (surgical site close to kidney) Residual tumor Rebound hypoglycemia (lots of epi = hyperglycemia)

Question 33

What is the first line treatment for cocaine toxicity?

Answer 33

Benzodiazapenes (like Ativan)

Question 34

What structure regulates/stimulates the pituitary gland to release its hormones?

Answer 34

Hypothalamus

Question 35

What hormones are released by the anterior pituitary gland? The posterior pituitary gland?

Answer 35

Anterior: Prolactin, GH, FSH, LH, TSH, ACTH Posterior: Vasopressin/ADH, Oxytocin

Question 36

What is the most common reason for patients to undergo a trans-sphenoidal resection of pituitary tumor?

Answer 36

Often due to an adenoma

Question 37

What are some common symptoms of pituitary tumors/adenomas?

Answer 37

Headaches Visual problems (pituitary sits on top of optic chiasm)

Question 38

Other than pituitary adenoma, what are some other commonly seen pituitary diseases?

Answer 38

Acromegaly (excess release of GH) DI (diabetes insipidis) SIADH (syndrome of inappropriate ADH)

Question 39

What is acromegaly caused by? What are some anesthetic considerations to keep in mind with these patients?

Answer 39

Usually caused by excess GH secretion (Growth Hormone) Usually accompanied by HTN and DM Anticipate difficult airway Veins and arteries may be enlarged (do Allen's test if A-line will be used)

Question 40

What is SIADH characerized by? What are common causes of SIADH?

Answer 40

SIADH is characterized by excess release of ADH. This will lead to hyponatremia due to serum dilution from water retention Common causes: head injuries, tumors, small cell carcinoma of lungs

Question 41

What causes Diabetes Insipidus? What is it characterized by?

Answer 41

DI causes: neurogenic (pituitary stops making it), nephrogenic (ADH stops working in the kidneys) Characerized by hypernatremia and hypovolemia due to loss of water

Question 42

How would you treat SIADH intra op?

Answer 42

Fluid restriction Lasix

Question 43

How would you treat DI intra op?

Answer 43

Replace losses of water