Endocrine Flashcards
3 types of hormones
- peptide/protein: stored in granules then released: insulin, ADH GH
- amino/amino: catecholamines, thyroxine
- lipids: derived from cholesterol, not stored, usually bound to plasma proteins: steroid
hormone control mechanisms (3)
- neural
- biorhythms
- feedback
endocrine system
- regulation of behavior
- growth
- metabolism
- fluid status
- development
- reproduction
pituitary gland
- pea-sized gland in sella turcica (sphenoid bone)
- connected to hypothalamus by hypophyseal stalk
anterior pituitary gland
- 80% of pituitary
- communicates with hypothalamus via vascular system
- GH, TSH, ACTH, FSH, LH, prolactin
posterior pituitary gland
- communicates with hypothalamus via neural pathways (hormones already synthesized)
- ADH, oxytocin
panhypopituitarism
- lack of all pituitary hormones
- more common than a decrease in a single hormone
pituitary gland: hyposecretion - causes
- large nonfunctional pituitary tumors
- postpartum shock
- irradiation
- trauma
- hypophysectomy
pituitary gland: hyposecretion - treatment
- require thyroid and steroid replacement peri-op
- diabetes insipidus after removal: have vasopressin
- surgical approach is transphenoidal
anterior pituitary: hyposecretion - transphenoidal approach considerations
- sitting position
- precordial doppler and EtCO2 monitoring for air embolism
- smooth intubation and extubation
- quick emergence to allow for neuro checks
- no N2O
- intraoperative muscle relaxation
- will have nasal packing
anterior pituitary: hyposecretion - transphenoidal approach complications
- CSF leak
- meningitis
- ischemic stroke
- visual loss
- diabetes insipidus
- hyponatremia
- epistaxis
- cranial nerve damage
anterior pituitary: hypersecretion of growth hormone - acromegaly
- bones and organs are enlarged
- lung volumes increase with increased extrathoracic obstruction
- coarse facial features
- glucose intolerance and diabetes
- cardiac problems
**caution with airway: mask fit difficult, smaller ETT due to larger vocal cords, OSA, difficult DL
posterior pituitary: ADH release
- 284 mOsm/L
- 10-20% decrease in plasma volume or BP: baroreceptors send signal via vagal and glossopharyngeal nerves
- pain
- emotional stress
- nausea
**surgery increases ADH release
posterior pituitary: diabetes insipidus treatment
- neurogenic versus nephrogenic
- vasopressin (short term), desmopressin (long term)
- monitor plamsa osm, UOP, Na qh
- isotonic fluids if serum osm < 290, hypotonic if >290
posterior pituitary: SIADH treatment
- fluid restriction
- hypertonic saline with lasix
what is the rate limiting step in thyroid hormone formation?
iodide trapping - which is under the control of TSH
thyroid gland: effects of hormone
- increased metabolic rate and heat production
- increased O2 consumption
- increased heart, liver, kidney function
- role in growth and development
thyroid gland: hormones secreted
- T4: most abundant, less potent, non-active
- T3: less abundant, more potent, active
- calcitonin: regulates short term calcium
thyroid gland: nerves nearby
- recurrent laryngeal
- external motor branch of superior laryngeal
thyroid gland: location
- below larynx
- both sides and anterior of trachea
thyroid gland: thyrotoxicosis S/S
- goiter
- tachycardia
- heat intolerance
- weight loss
- eye signs
- a-fib
- skeletal muscle weakness
- anxiety
- tremor
- insomnia
- fatigue
thyroid gland: thyrotoxicosis diagnosis
- low TSH
- high T4
thyroid gland: thyrotoxicosis treatment
- inhibit hormone synthesis (methimazole, propylthiouracil)
- prevent hormone release (potassium, sodium iodine)
- mask adrenergic overactivity
- radioactive iodine
- surgical removal
thyroid gland: thyrotoxicosis preoperative management
- needs to be euthyroid
- continue antithyroid and BB
- assess airway: enlarged thyroid can cause tracheal deviation
- blood volume increased, PVR decreased, pulse pressure wide
thyroid gland: thyrotoxicosis intraoperative management
- avoid SNS stimulation (no ketamine, pancuronium, atropine)
- monitor core temperature
- treat hypotension with direct-acting vasopressors
- avoid hypercarbia and hypoxia (because they stimulate SNS)
- increased incidence of myopathies and myasthenia gravis: no muscle relaxants after induction
- ETT with NIM (+ electrodes on vocal cords)
thyroid gland: thyroid storm occurrence time
- anytime in peri-op period
- most likely 6-18 hours post-op
thyroid gland: thyroid storm versus malignant hyperthermia
-malignant hyperthermia has sudden rise in EtCO2 and trismus
thyroid gland: thyroid storm treatment
- iv hydration with glucose-containing fluids
- Tylenol (cooling)
- BB
- potassium iodide
- correct electrolyte and acid-vase imbalances
- antithyroid drugs
thyroid gland: recurrent laryngeal nerve palsy
- unilateral: hoarseness
- bilateral: aphonia and stridor = immediately reintubate
thyroid gland: hypothyroidism S/S
- myxedema
- lethargy
- hypotension
- bradycardia
- CHF
- gastroparesis
- hypothermia
- hypoventilation
- hyponatremia
- poor mentation
thyroid gland: hypothyroidism diagnosis
- low T4
- high TSH
thyroid gland: hypothyroidism preoperative assessment
- myocardial function and baroreceptors may be depressed
- airway evaluation: large thyroid gland and tongue, myxedematous
thyroid gland: hypothyroidism peri-operative
- -hypotension: reduced plasma volume
- sensitive to non-depolarizers
- less sensitive to inotropic drugs
- slower GI emptying
- monitor core temperature
- risk for hypoxia and hypercarbia
thyroid gland: myxedemia
- high risk of anesthetic complications
- hypothyroidism, hypothermic, hypoventilation, hyponatremic
- only life-saving surgeries
90% of the time hyperparathyroidism is due to _____
adenoma
parathyroid gland: hyperparathyroidism diagnosis
-high Ca and PTH levels
parathyroid gland: hyperparathyroidism S/S
- profound muscle weakness
- confusion
- N/V
- lethargy
- calcifications
parathyroid gland: hyperparathyroidism treatment
- hypercalcemia if treated with isotonic saline and loop diuretics
- surgical removal
parathyroid gland: hyperparathyroidism operative considerations
- dehydration
- avoid preop sedatives
- hyperventilation decreases ionized calcium, more calcium is bound
- sensitive to NM blockers (especially sux)
- treat arrhythmias and HTN with calcium channel blockers
parathyroid gland: hypoparathyroidism operative consideration
- potential for hypocalcemia and laryngospasm
- avoid hyperventilation decreases ionized calcium
pancreas - secretory cells
islets of langerhans
beta=insulin
alpha=glucagon
delta=somatostatin
F cell=pancreatic polypeptides
average patient with diabetes will spend ____ more time in the hospital recovering from surgery
50%
diabetes: chronic complications
- HTN
- peripheral, retinal, and cerebral vascular disease
- increased risk of silent MI
- autonomic neuropathy
- renal failure
diabetes: anesthesia considerations
- evaluate end order damage
- evaluate cardiac status
- gastroparesis with delayed gastric emptying
- impaired respiratory response to hypoxia
- limited-mobility joint syndrome
- neuropathies
- kidney function
diabetes: cardiac-diabetic autonomic neuropathy
- HTN
- orthostatic hypotension
- lack of HR variability
- resting tachycardia
- lack of sweating
- silent MI
- asymptomatic hypoglycemia
- reduced HR response to atropine or propranolol
diabetes: anesthesia care
- first case of day
- fluids=normal saline, no lactated ringers
- half or hold dose
- measure glucose
diabetes: metformin
- hypotension
- renal impairment
- lactic acidosis
*hold 48 hours prior to surgery
diabetes: avoid ____ when patient takes NPH because it causes _____
protamine – anaphylaxis
diabetes: hypoglycemia S/S
- diaphoresis
- tachycardia
- nervousness
- confusion
diabetes: hypoglycemia treatment
-25-50 mL of D50, followed by D5 drip
in a 70kg pt, ___ mL of ____ can be expected to raise the blood glucose concentration by _____ mg/dL
15 mL
d50
30 mg/dL
diabetes: diabetic ketoacidosis
- type 1
- volume depletion and hyperglycemia
- fruity odor to breath
- Kussmaul respirations
- metabolic acidosis
- coma
diabetes: diabetic ketoacidosis triad
- hyperglycemia
- acidemia
- ketonemia
diabetes: diabetic ketoacidosis and hyperglycemia hyperosmolar state treatment
- IV insulin
- fluids
- correct electrolyte and acid/base imbalances
diabetes: hyperglycemia hyperosmolar state
- type II
- glucose > 600
- hypovolemia and hypotension
- seizures, coma
- tachycardia
adrenal glands: hormones
adrenal cortex: mineralcorticoids (aldosterone), glucocorticoids (cortisol), androgens
adrenal medulla: catecholamines (norepinephrine, epinephrine)
adrenal glands: cortisol function (4)
- gluconeogenesis
- protein mobilization
- fat mobilization
- stabilizes lysosomes
adrenal glands: hyperaldosteronism types
- primary (Conn syndrome): from adrenal adenoma
- secondary: increased renin production
adrenal glands: hyperaldosteronism anesthetic plan
- correct fluid/electrolyte balance
- HTN: spironolactone is aldosterone antagonist
- avoid hyperventilation because it drives K into cells
- monitor EKG and muscle relaxants due to low K
adrenal glands: Cushing syndrome anesthetic plan
- correct fluid/electrolyte balance
- care with skin and positioning
- increased infection risk
- supplement steroids
adrenal glands: Addison’s disease anesthetic plan
- correct fluid/electrolyte balance
- steroid replacement
adrenal glands: Addison’s disease S/S
- all 3 hormones deficient
- hyperpigmentation
- weight loss, fatigue, weakness
- hypotension, hyponatremia, hyperkalemia, hypoglycemia
what induction medication should be avoided in Addison’s disease and why
-etomidate: interferes with steroids
adrenal glands: pheochromocytoma definition
- catecholamine-secreting tumor
- can be malignant, bilateral, and extra-adrenal
adrenal glands: pheochromocytoma S/S (4)
- paroxysmal headache
- hypertension
- sweating
- palpitations
adrenal glands: pheochromocytoma diagnosis
- urine metanephrine level: false positive due to coffee, tricycles, phenoxybenzamines
- suppression test: clonidine decreases catecholamines that are neurogenically controlled
adrenal glands: pheochromocytoma pre-operative
- alpha blocker (phenoxybenzamine titrate to 1 mg/kg by 10-20 mg every 2-3 days)
- beta blocker
adrenal glands: pheochromocytoma pre-operative treatment endpoints
- BP <160/90
- <1 PVC q5min
- presence of orthostatic hypotension
- absence of EKG changes for 1 week
- HCT <5% for adequate intravascular volume expansion
adrenal glands: pheochromocytoma anesthetic considerations
- A-line
- 2 large bore IV
- CVP
- deep intubation
- Foley
- anticipate labile BP, avoid SNS stimulation (ketamine, ephedrine) and histamine release (morphine, atracurium)
multiple endocrine neoplasia: MEN 1
- parathyroid
- pancreatic
- pituitary
multiple endocrine neoplasia: MEN 2
- medullary thyroid
- pheochromocytoma
- parathyroid
multiple endocrine neoplasia: MEN 3
- mucosal neuromas
- pheochromocytoma
- medullary thyroid
carcinoid syndrome: definition
- complex of S/S caused by the secretion of vasoactive substances from enterochromaffin cells
- serotonin (constrict), histamine (dilate), kallikrein (dilate)
- mainly in GI tract
carcinoid syndrome: S/S (5)
- R sided heart failure
- dramatic BP swings
- cutaneous flushing
- bronchospasm
- diarrhea and abdominal pain
carcinoid syndrome: pre-operative
- histamine blocker
- octreotide (2 weeks)
- evaluate extra-intestinal manifestations
carcinoid syndrome: anesthetic considerations
- A-line
- 2 large bore IV
- CVP
- deep intubation
- steroids, histamine blockers
- avoid histamine releasing substances
- vasopressin for refractory hypotension
- have octreotide available
liver’s role in carbohydrate metabolism (3)
- glycogenesis
- glycogenolysis
- gluconeogenesis
glucose transporters (4)
GLUT 1: all cells, RBCs, BBB
GLUT 2: renal, GI
GLUT 3: neurons
GLUT 4: adipose, muscle
