Endocrine Diseases Flashcards
what does the anterior pituitary gland produce? (6)
- adrenocorticotrophic hormone (ACTH)
- thyroid stimulating hormone (TSH)
- growth hormone (GH)
- follicle-stimulating hormone (FSH)
- lutenizing hormone (LH)
- prolactin
what does the posterior pituitary gland secrete?
- anti-diuretic hormone (ADH)
- oxytocin
how is secretion from the anterior pituitary regulated?
the hypothalamus
*transported via capillary portal system
what is the difference in how hormones are produced and secreted by the anterior and posterior pituitary?
- anterior PRODUCES hormones and releases them into circulation under hypothalamus control
- posterior SECRETES hormones produced in the hypothalmus after neural stimulation
where does prolactin act?
prolactin acts on the milk producing cells in the breast, causing lactation
where does ACTH act?
the adrenal cortex, releasing adrenalin
where does GH act?
the body’s cells, causing growth
what does TSH do?
acts on the thyroid, causing thyroxin secretion, stimulating growth and metabolism
where does FSH and LH act?
the testes and ovaries, causing
- androgen and sperm production
or
- egg production
where does oxytocin act?
the uterus, causing labour contractions
where does ADH act?
the kidneys, regulating water levels
what is the difference between T4 and T3?
T3 is more potent and less protein bound,
but glands release more T4 (10:1)
whats T4 called?
thyroxine
whats T3 called?
tri-iodothyronine
what is hyperthyroidism?
overproduction of T3 and/or T4
what can cause hyperthyroidism?
- grave’s disease
- TSH-secreting pituitary tumors
- iatrogenic (caused by medicine)
- thyoiditis
what are symptoms of hyperthyroidism?
- weight loss
- fatigue
- arrhythmias
- anxiety
- exopthalmos (eyeballs popping out)
- widened pulse P
what do T3 and T4 act on?
adenylate cyclase
- affects speed of rxns, O2 use, and energy output (heat production)
whats the most common cause of hyperthyroidism?
graves disease
*in women 20-40 yo
how do you treat hyperthyroidism?
- antithyroids or beta antagonist
- surgical total, subtotal or lobar thyroidectomy
what intra-op considerations would you have for a PT with hyperthyroidism?
- esmolol
- no SNS stimulants
- PTs usually hypovolemic
- NO change of MAC
- exaggerated hypotensive response upon induction
what are some post op concerns for hyperthyroidism?
- RLN injury (horseness)
- hematoma/tracheomalacia
- hypocalcemia
what does radioiodine do? Specific to the thyroid?
destroys thyroid cell function
what pre-op info is relevant for elective thyroidectomy?
- RHR
what is the most serious post-op threat for thyroid PTs?
- thyrotoxic crisis (thyroid storm)
* usually 6-18hrs post-op
what are symptoms of thyrotoxic crisis?
- abrupt axiety
- fever
- tachycardia
- cardiovascular instability
treatment of thyrotoxic crisis?
- IV cooled crystalloids
- continuous esmolol infusion
- dexamethasone (2mg q6)
or cortisol (100-200 mg q8)
what can inhibit conversion of T4 to T3?
propylthiouracil (250-500 mg q6 PO)
what muscle relaxant should we avoid with hyperthyroid PTs?
pancuronium
what condition does thyrotoxic crisis mimic?
malignant hyperthermia
what is a primary cause for hypothyoidism?
dysfunction/destruction of thyroid tissue
- Hashimoto’s Thyroiditis
- high TSH but low T3/T4
what is a secondary cause for hypothyroidism?
hypothalmic/pituitary axis disfunction
- normal or low TSH and low T3/T4
- iatrogenic
- myxedema coma
what are sympoms of hypothyroidism?
- lethargy
- weight gain
- cold intolerance
- hypoactive reflexes
how can you treat hypothyroidism?
PO T4
*synthroid
what is an extreme case of hypothyroidism more common in elderly women with a long history of hypothyroidism?
myxedema coma
What should be done with hypothyroid PTs preop?
- minimize premed
- gastric emptying
- TAKE YOUR SYNTHROID
- warm
what are some intraop concerns for hypothyroid PTs?
- hypotension and increased sensitivity to agents
- blunted baroreceptors
- maybe avoid GA if possible
- use KETAMINE if you must do GA
why might hypothyroid PTs have impaired pulmonary function?
TH aids in surfactant production
how does PTH affect serum calcium and phosphate?
- increases calcium (bone resorption, dec. excretion)
- decreases phosphate (renal excretion)
what can cause primary hyperparathyroidism?
- adenoma
- carcinoma
- hyperplasia of PTH glands
what can cause secondary hyperparathyroidism?
PTH increase due to hypocalcemia
what are symptoms of hyperparathyroidism?
- hypercalcemia
* renal stones, HTN, constipation, fatigue
what medical treatment can be done for hyperparathyroidism?
- saline
- loop diuretics
what causes hypoparathyroidism?
decreased PTH by iatrogenic causes
what symptoms result from hypoparathyroidism?
result from hypocalcemia
- acute paresthesia, NM irritability
- chronic EKG changes, lethargy, cataracts
what should we avoid in hypoparathyroid PTs?
don’t hyperventilate
what is a positive chvostek’s sign?
facial muscle twitching with tapping the mandible
*for nerve hypersensibility
what is a positive trousseau’s sign?
occluding brachial artery for 3 minutes, causes spasm of forearm due to hypocalcemia
- for nerve hypersensibility
- more sensitive than chvosteks sign
what is DiGeorge syndrome?
congenital hypoplasia of the thymus and parathyroid
what does the thymus do?
immune organ that develops lymphocytes into T-cells for adaptive immune function
what may you see in your airway exam for PTs with DiGeorge syndrome?
micrognathia
what concerns do you have for Digeorge syndrome peri-op?
- NMB unpredictable
- hypervent could exacerbate hypocalcemia
- micrognathia
What does the adrena medulla secrete?
catecholamines (epi, norepi, dopamine)
what does the adrenal cortex secrete?
- glucocorticoids (cortisol)
- minerocorticoids (aldosterone, Na, K)
what stimulates the adrenal cortex to release cortisol?
corticotropin
glucocorticoids have a role in what metabolic pathway?
gluconeogenesis (inhibiting peripheral glucose use, causing hyperglycemia)
what is the net effect of aldosterone? (3)
- increased extracellular fluid volume
- decreased plasma K+
- metabolic alkalosis
how are androgens significant for anesthetic management?
THEYRE NOT
what important disease process is associated with the adrenal medulla?
PheoChromoCytoma (PCC)
what causes cushing’s syndrome?
excess cortisol by ACTH -secreting adenoma
what are symptoms of cushing’s?
- obesity
- HTN
- muscle wasting
- glucose intolerance
- osteoporosis
what are some preop considerations for cushing’s syndrome PTs?
- BP, electrolytes, hypervolemic and hypokalemic
- blood sugar
intraop considerations for cushings
osteoperosis and obesity
post op considerations for cushings
- poor would healing
- infection
what is conn syndrome?
hyperaldosteronism, usually caused by a tumor
what are symptoms of conn syndrome?
- metab. alkalosis
- hypokalemia
- headache, cramps
what can be done to treat conn syndrome?
- spironolactone
- surgery
what can be done perioperatively for PTs with Conn syndrome?
- treat hypokalemia
- treat any HTN
what is spironolactone?
an aldosterone antagonists
- a K+ sparing diuretic
what is a primary adrenocorticoid deficiency?
addison’s disease (autoimmune)
what is a secondary adrenocorticoid deficiency?
cortisol deficiency with normal aldosterone, caused by chronic steroid use
what are some symptoms of adrenocorticoid deficiency?
- hypotension
- hyponatremia
- hypovolemia
- hyperkalemia
- fatigue
- hyperpigmentation
how do you treat adrenocorticoid deficiency?
replace minero/glucocorticoids
*hydrocortisone 100 mg q6 hrs
what should you be aware of peri-op for PTs with adrenocorticoid deficiency?
addisonian crisis
- keep stress free
- avoid etomodate
what causes hypoaldosteronism?
- congenital deficiency of aldosterone synthase
- hyporeninemia
- adrenalectomy procedure
how do you treat hypoaldosteronism?
fludrocortisone (a minerocorticoid)
what is pheochromocytoma?
PCC is a catecholamine secreting tumor of the medulla, secreting NE and Epi 85:15
what are some signs of PCC?
- sudden malignant HTN
- cardiac dysrhthmias
- headache
- perspiration
how much NE does the average PCC tumor contain?
100-800 mg NE
how do you treat PCC?
cut out the tumor, manage BP with alpha-antagonists and B blockers
what can result peri-op with PCC PTs?
- HTN before removal
- Hypotension after
- HTN crisis can cause blindness
- CVA
- have an A-line
what causes acromegaly?
excess GH, usually from a tumor on pituitary gland
what will a PTs airway with acromegaly look like?
excess soft tissue & catilage, making DL difficult
*increased subglottic stenosis incidence
what is diabetes insipidus?
deficiency or resistance to vasopressin
what are symptoms of diabetes insipidus?
extreme thirst, excess urination
how do you treat neurogenic diabetes insipidus?
- synthetic vasopressin (desmopressin)
* due to lack of vasopressin secretion
how do you treat nephrogenic diabetes insipidus?
- keep Na+ levels low w/ diuretics
* vasopressin levels should be normal, just decreased response
what should we monitor peri-op with diabetes insipidus?
electrolyte imbalances
- high Na+
- low K+
- low Mg2+
___ % of glucose production comes from hepatic glycogenolysis and ___ % comes from hepatic gluconeogensis during the postabsorption phase of digestion.
75%, 25%
what is a normal hemoglobin A1C?
what do the Islets of Langerhans do?
75% B cells - secrete insulin
20% a-cells - secrete glucagon
what does glucagon do?
increases glycogen breakdown in the liver (gluconeogensis)
what does insulin do?
lowers blood glucose by transporting glucose into the cell
what does somatostatin do (from Delta cells)?
decreases motility of stomach, duadenom, gall bladder to increase absorption time
*inhibits insulin, glucagon, growth hormon, gastrin, motilin
how is glucagon and insulin affected by parasympathetic and sympathetic innervation? (T5-T10)
- sympathetic stimulates glucagon release
- parasympathetic stimulates insulin release
what hormones can stimulate insulin release?
GH and cortisol
what effect can lack of insulin have on glucose, fat and protein?
- cells cant use glucose
- increase fat as energy source, increase lipase and LDL
- increase muscle wasting
what are the type of DM?
type I - 5-10% of cases, autoimmune destruction of B cells
type 2 - 90%, insulin resistance
gestational - 2-3% of pregnancies, resolves post partum, dangerous for baby
what are symptoms of DM?
- polyurea, polydypsia, polyphagia
- weight loss from muscle/fat used as energy
- asthenia (no strength)
- sweet breath from acetone
- vision problems until blood sugar controlled
long term complications of DM
- HTN
- vascular disease
- neuropathy
- renal failure
what is the most common cause of death in older diabetics?
- MI
* 20x greater risk periop
what is diabetic ketoacidosis? (DKA)
decreased insulin activity leading to more metabolism of fatty acids and an accumlation of organic acids by-products
*occurs when exogenous insulin isn’t given
how do you treat DKA?
crystalloid and insulin
what are clinical signs of DKA?
blood sugar 320+ fatigue polyuria mental stupor ketones in urine
what is a hyperosmolar non-ketotic coma?
hyperglycemic (600+ BS) diuresis that results in dehydration and hyperosmolality
what do you do to treat hyperosmolar non-ketotic coma?
hypotonic solution and insulin
what causes hypoglycemia?
insulin > carb intake
- BS ~50mg/dL
- mostly Type I DM
how do you treat hypoglycemia?
IV administration of 50% glucose (each mL will raise BS about ~2mg/dL
regular insulin can be given IV. All other insulin products must be given how?
subcutaneously
what is metformin for?
1st line for obese type II DM PTs. decreases insulin requirements
what are the four major classes of oral hypoglycemics?
- secretagogues (sulfonylureas)
- biguanides (metformin)
- glitazones
- a-glucosidase inhibitors (acarbose)
when do you treat high glucose intra-op?
when BS is >150 mg/dL
*check every hr
how do you treat high blood sugar intra-op?
give insulin
*(bs-100)/40 = units of insulin to give
how much will 1 unit of insulin lower blood sugar?
25-30 mg/dL
what is carcinoid syndrome
tumors of the GI tract causing massive serotonin and histamine release
what will you see with carcinoid syndrome?
flushing and diarrhea, maybe massive hypotension
what can you do to treat carcinoid syndrome?
- a line
- zofran
- octreotide, somatostatin
