by gnomey


keywords:
Bookmark and Share



Front Back
Description of protein or peptides?
Proteins or peptides- within the endocrine cells and stored for release by exocytosis
Examples of amines or amino acids
thyroid hormones and catecholamines

-byproducts of tyrosine
What are steroids derived from? examples
- Derived from cholesterol

examples: cortisol, aldosterone, and testosterone
What type of feedback is used in regulation of endocrine hormones? example
Negative feedback response

-Elevated T3 and T4 levels cause decreased TSH release from anterior pituitary gland
What 3 mechanisms regulate production and secretion of hormones?
1. Neural control
2. Biorhythms
3. Feedback
What hormones are produced by the anterior pituitary gland?
Five distinct cell types
1. Growth hormones
2. Thyroid stimulating hormone
3. Adrenocorticotropic hormone
4. Prolactin
5. FSH and LH
What hormones are produced by the posterior pituitary gland?
Oxytocin
Vasopressin
What are two diseases caused by adenomas on the pituitary gland?
Cushings syndrome
Acromegaly
What are elevated prolactin levels?
1000-4000m U/L
What is the firstline treatment for Prolactin secreting tumors?
Dopamine agonist
-bromocriptine
-cbergoline
What condition is caused by excess growth hormone? what gland?
Acromegaly
caused by excess GH production by the anterior pituitary gland in adulthood after the closure of the epiphyseal plates
What complication of acromegaly can affect airway management?
1. soft tissue overgrowth
2. macrognathia causing prognathia
What are cardiac and endocrine changes related to acromegaly?
1. HTN, Cardiomgaly, Impaired LV function
2. Impaired glucose tolerance, DM

Organomegaly of liver, heart, spleen, and kidneys
What are the 2 types of pharmacological treatment for acromegaly?
1. Dopamine agonists- few respond to this
2. Long acting somatostatin drugs (octreotide)- used if dopamine agonists fail
What is cushing's disease related to?
1. excess ACTH secretion by the anterior pituitary gland
2. adrenal adenoma
3. ectopic ACTH secreting neoplasm
4. secondary to treatment with glucocorticoids
What causes the symptoms related to hyperadrenocorticism?
1. related to hormones released by the pituitary gland
2. ACTH- causing relase of aldosterone, cortisol, and adrogens
What are the two main goals of anesthesia for transsphenoidal surgery?
CV stability- prevent HTN, tachycardia, and wide swings in BP

Maintenance of cerebral oxygenation
What happens if a patient is being hyperventilated during transsphenoidal surgery?
hypocarbia causes vasoconstriction of cerebral vasculature which causes lifting of the cerebrum and movement of pituitary gland away from surgical site
Major and CV manifestations of hyperthyroidism?
Weight loss, diarrhea, skeletal muscle weakness,and stiffnes

CV: increased LV function, inc EF, tachycardia, wide pulse pressure
what is the purpose of propylthiouracil and methimazole?
Prevent the body from making iodide and therefore the synthesis of TH
how long does medication therapy take to lower TH levels to normal? why?
6-8 weeks, bcause the thyroid stores enough hormone to maintain euthyroid levels for several months
What iodide conversion inhibitor prevents peripheral conversion of T4 to T3? what b-blocker does this also?
propylthiouracil
Propanolol, over 1-2 weeks
What is the goal for HR control in hyperthyroid patient?
<90 bmpm
Administration of glucocorticoid during a thyrotoxicosis event provides what benefit?
1. Reduce thyroid hormone secretion
2. prevent peripheral conversion of T4 to T3
main goal of intraoperative maintenance for a patient with hyperthyroid?
1. Acheive a depth of anesthesia that blunts SNS response to surgical stress
2. Avoid anesthetic drugs that mimic or induce SNS responses
What is the treatment plan for thyroid storm during surgery?
1. IV fluids with glucose
2. Sodium iodide 250mg po or IV
3. Propylthiouracil 200-400mg po
4. Hydrocortisone 50-100mg IV
5. Propanolol 10-40mg or esmolol
6. cooling blankets
7. Dig for HF and especially in face of AFib w/ RVR
When do symptoms of hypocalcemia present following thyroidectomy surgery?
24-96 hours post op
What is one of the first signs of hypocalcemia r/t removal of parathyroid glands?
Stridor progressing to laryngospasm
-first sign of hypocalcemic tetany
What are CV manifestations of hypothyroidism?
Due to low T4 and T3 levels:
1. Low CO
2. Bradycardia
3. Increased peripheral resistenance
What ventilatory responses are depressed in hypothyroid pt?
Hypoxia and hypercarbia
-augmented by sedatives, opioids, and general anesthetics
Manifestations of myxedema coma?
R/t hypothyroidism
1. hypothermia
2. HOTN
3. Hyponatremia
4. Hypoventilation
5. Coma or stupor
What is the risk of treating a hypothyroid patient with thyroid hormones?
May precipatate myocardial ischemia
Treatment for myxedema coma?
1. IV thyroid hormones 200-300mcg iV over 5-10min
2. Hydrocortisone 100mg IV
3. Fluid and electrolyte replacement
4. cover to conserve body heat, no warming blankets (peripheral dilation augments HOTN)
What is the relationship to albumin and calcium levels?
Calcium is highly bound to albumin

Inc or dec in albumin 1gm/dL=0.8 serum Ca change in same direction
How does acidosis and alkalosis influence iCa?
pH and temp influence Ca and albumin bonding
1. acidosis decreases bonding, therefore increases iCa
2. alkalosis increases bonding, therefore decreases iCa
What regulates PTH secretion by the parathyroid glands?
serum iCa concentrations
Function of PTH?
1. causes release of Ca from bones (resorption) (most rapid change of Ca levels)
2.Direct resportion of Ca at distal tubules of kidneys
What is the purpose of hydrooxylation of Vitamin D in the kidneys?
Hypocalcemia and hypophosphotemia cause the kidneys to metabolize 1,25 OH2D and decrease of 24,25 OH2D. This causes increased intestinal absorption of calcium and phosphate
At what serum Ca levels is treatment required before surgery can continue? treatment?
Serum Ca >15mg/dL
1. Intravascular volume expansion with NS, dilutes serum and dec by 2mg/dL or greater.
2. Diuresis, IV Furosemide to promote Ca excretion with Na excretion
What must be avoided during surgery if a rapid PTH assay is going to be used?
No propofol within 15 minutes of assay
What is the daily amount of endogenous cortisol production?
20mg
What 3 factors primarly influence the production of ACTH and CRF?
1. sleep-wake cycle
2. stress
3. glucocorticoid plasma concentrations (primarily cortisol levels)
How do glucocorticoids (cortisol) influence the immune system?
1. Anti-inflammatory effects (stabilize leukocytes and maintain capillary wall integrity)
2. Antagonize leukocyte migration inhibition factor->decrease response to local inflammation
3. Reduce killing potential of macrophages and monoctyes, not their activity though
How does the renin-angiotensin system regulate the release of aldosterone?
1. Juxtaglomeular apparatus surrounds the renal afferent arterioles
2. in response to hypoperfusion or SNS stimulation of the Juxta apparatusĀ  renin is released
3. Renin splits angiotensinogen to form angiotensin I
4. Angiotensin I is converted to Angiotensin II by an enzymes in the lungs
5. Angiontensin II stimulates the adrenal cortex to produce aldosterone
What is angiotensin II?
Result of renin-angiotensin system
1. most potent endogenous vasopressor
2. Stimulates adrenal cortex to produce aldosterone
What are the S & S of Cushing syndrome?
1. Tuncal obesity and thin extremities that reflect muscle wasting and redistribution of fat
2. Osteopenia r/t impaired Ca absorption
3. Hyperglycemia, with DM in 20%
4. HTN and fluid retention
5. Risk of infection d/t immunosupressive effects of corticosteroids
Is Hypokalemia seen with an endocrine tumor?
no see with nonendocrine tumor
What is the difference between primary pituitary disease and adrenal tumors?
1. Exogenous glucorticoid administration causes decrease levels of cortisol and 17-hydroxycorticosteroid levels in PRIMARY PITUITARY because some negative feedback control exists
What diuretic is helpful in diuresing patient with Cushing's and normalizing intravascular volume?
Spironolactone, aldosterone antagonist
- helps normalize K+ concentrations
What adrenal cortex response does supraphysiologic hydrocortisone doses mimic?
Exerts significant mineralocorticoid activity
x of y cards Next >|