thyroid disease and their anesthetic considerations – Flashcards

highly vascular 5th-1st thoracic lobes are connected by an isthmus

-recurrent laryngeal, inferior laryngeal artery and inferior laryngeal vein branches off vagus, dips off into chest and back into gland. supplys all lryngeal muscles except the crycothyroid membran which is supplied by superior laryngeal nerve.

it essentially increase the metabolic rate, increases proteins synthesis, neural maturation, and increased sensbility to catacolimenes.

T4 (thyroxine), this is low in hypothyroid

TSH- this is the moste sensitive to mild hypothyroidism

HYPERTHYROID: decrease SVR, increased HR, increased EF, increased CO, increased blood volume HYPOTHYROID: increased SVR, decreased HR, decreased EF, decreased CO, decreased Blood volume

multinodule goiter from graves disease is common amiodorone is rich in iodine and can cause iodine incued thyrotixicosis

because with hyperthyroidism antibodie bind in retro-orbital area casing swelling the eyes

red swollen skin

Thioura deritives: methimazole, propythiouracil, (inhibit iodine, so thyroid cannot make thyoid hormone)

Life threating Tachycardia - hyperpyrexia - CHF - dehydration - shock - full bounding pulse - hypertension - atrial fibrillation - sweating, tremor - vomiting and diarrhea - confusion - agitation delirium - coma - metabolic acidosis can cause cardiovascular collapse, want to normalize thyroid function before surgery, can take 6-8 weeks to attain euthyroidism.

Thiopental. avoid sympathetic nervous sytem stimulates: pavulon, ketamine, ephedrine. protect patients eyes, and this disorder does not increase MAC.

oxygen electrolyte imbalance inderal-esmolol-potassium iodine-cortisol

-Normalize thyroid function prior to surgery -Pre-medicate -Induction agent of choice (thiopental if available) -Avoid sympathetic stimulants -Atrial fibrillation is present in 10-20% of pt Assessment of fluid and electrolyte balance -Airway assessment -Substernal goiters - Tracheoesophageal compression

want to monitr CA++ for 24-72 hours after surgery

hashimots is the most common

primary is more comone

untreated in children can lead to mental retardation and stunted growth

from hypothyroidism. this is medical emergency with 50% mortality. rare, does not effect MAC, the temperature regulations of these patients may effect the MAC of anesthesia

may want to give hydrocortisone

Neurologic changes Renal changes decreased glomerular filtration rate - decreased creatinine clearance - decreased free-water excretion Miscellaneous changes Decreased factors VIII & IX - decreased cholesterol Concomitant adrenal insufficiency Ileus & gastroparesis SIADH

sensitive to drugs, may need RSI, fluid, difficult weaning -Hypothermia -Anemia -Hypoglycemia -Adrenal insufficiency (hydrocortisone) -Induction with ketamine or other hypnotic -Consider RSI MAINTENANCE ANESTHESIA -Minimize use of volatile anesthetics -Decreased cardiac output (take longer to get off) -Controlled ventilation - Maintain muscle relaxation -Avoid hypothermia -Postoperative respiratory depression -Consider adrenal insufficiency in refractory hypotension and give hydrocortisone

Calcium -GI absorption 0.5-1.0 g/day (duodenum/jejunum) -Body reservoir of 1000 grams -Total serum calcium 8.8-10.4 mg/dL -40-50% (ionized), 40% protein bound (nonionized), 10-20% chelated nonionized -Normal renal excretion of 300-400 mg/day (maximum of 500 mg/day)

it is stimulated by high levels of phosphate and low levels of magnesium and low serum ca+

all are decreased. can be associated with adenomas -Serum calcium above 11-12 mg/dL Concentration >14 may be life threatening -Generalized weakness -Renal: calculi, polyuria, polydipsia -Cardiac: HTN, short QT, prolonged PR -Skeletal: pain & pathologic fractures -Hematologic: anemia -CNS: somnolence. Psychosis, decreased pain

sedation vomiting, hypotonia, myasthenia gravis resemblense, systemic hypertension

Thiazides will increase CA+ reabsorption

- can treat with calcium channel blocker -hypophosphate may leave calcium unopposed so make sure phsophate is adequate

low calcium -Hypocalcemia -Ionized calcium < 4.5 mEq/L -Prolonged QT with normal PR -Hyperposphatemia Therapy Acutely: calcium infusion Chronically: Oral calcium - Vitamin D supplements chvosticks sign is with low calcium

27mg/ml of calium in chloride 9mg/ml of calcium in gluconate

stridor, tetany, monitor muscle block

Arterial blood supply -Abdominal aorta Renal arteries Phrenic arteries -Venous drainage Left gland: renal vein Right gland: inferior vena cava medulla is what secretes: NE, EPI, DOPA Glomerus: aldosterone

ACTH regulates their secreation, this is like cortisol reguate homeostais sympathetic response enhancement

regulates extracellular fluid volume through like aldosterone function. Aldosterone accounts for 95% of mineral corticoid activity, conserves sodium and maintains normal potassium levels

Hypokalemia and hypertension. this is because acth controls both minercorticoids and glucocorticoids aldosterone gets rid of K+ and holds onto NA thus retaining water

muscle weakness, crazy, renal stones, fat deposits, rotund belly, hypokalemia

A. 24 hour urine for free cortisol B. High dose decadron suppression test, distinguish between cushing and ectopic syndrome (the steriods will inhibit ACTH) -If A and B normal (cushing's is excluded) -If Cushing's is confirmed, then etiologic diagnosis needs to be done -? plasma ACTH concentration suggests a pituitary tumor -If tumor suspected, obtain MRI

want short acting dilators, patients may need blood pressure support when tumro has been removed. GIVE STRESS DOSE STEROIDS for hypophysectomy or Adrenalectomy

Two types: primary and secondary Primary: addisones, bilateral adreal distruction cannot produce glucocorticoids 2nd: hypothalmus or decreased acthTwo types: primary and secondary

-Hyperpigmentation -Postural and supine hypotension -Asthenia -Muscle weakness -Anorexia & malaise -Abdominal pain & vomiting -Diarrhea or constipation & wt. loss -Salt craving -Myalgias & arthralgias -Mental status changes Steroid treatment shuts down acth production, so the most common cause of insufficent hormone response, this is because of negative feedback, so the body will not ask for more steroids by activating adrenals. <5mg/day of prednisone do not display signs of adrenal insufiicency.

HYPONATREMIA-HYPERKALEMIA-HYPOGLYCEMIA GIVE STRESS DOSE STEROIDS

acth is not released

there is a lot of sodium retention and loss of K

Primary aldosteronism hypertension-Hypokalemic want to replace potassium and give diuretic

When blood volume is low, juxtaglomerular cells in the kidneys secrete renin directly into circulation. Plasma renin then carries out the conversion of angiotensinogen released by the liver to angiotensin I.[2] Angiotensin I is subsequently converted to angiotensin II by the enzyme angiotensin converting enzyme found in the lungs. Angiotensin II is a potent vaso-active peptide that causes blood vessels to constrict, resulting in increased blood pressure. Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the tubules of the kidneys to increase the reabsorption of sodium and water into the blood. This increases the volume of fluid in the body, which also increases blood pressure.

Restrict sodium and adminster spirolactone possibly adminster potassium, stress dose cortisone infusion.

Low aldosterone will have low na high K Hypovolemia

-#1Norepinephrine alone or in combination with epi -Epinephrine -Hyperglycemia and glucosuria -Dopamine -Centrally = Inhibits prolactin secretion Peripherally: -Small amount = renal vasodilation -Moderate = vasodilation of mesenteric and coronary vessels and peripheral vasoconstriction

measure urine catacholimines TRIAD ON TEST: HYPERTENSION, DIAPHORESIS, AND H/A

clonidine will not effect blood pressure if pheo is present

this can cause dilated cardiomyopathy and CHF

always use beta first, never want uninhibited alpha. if you used a beta blocker first then you may depress the heard and output and not be able to overcome the SVR

AVOID MORPHINE! Avoid morphine, because it causes histamine release causing vasodilation promting more catacholine release, tumor manipulation can cause bonkers

Morpine, atricurium avoid Droperidrol, metoprolcimde avoid Start off hyperglycemic, release insulin in the absenbce of alpha stimulation

Prepare for hypotension after tumor revmoval with phenylephrine

1.Hypotension and tachycardia 2.Hypoglycemia 3.Hypertension