Endocrine & Metabolic Disorders Part 2 Flashcards
(57 cards)
Adrenal Medulla: epi and norepi
Adrenal Cortex: glucocorticoids (cortisol), mineralocorticoids (aldosterone), and androgens
Adrenal Hormones
Controls release of cortisol, homeostasis, carbohydrate, protein, FFA metabolism, circulatory function, immune function, temperature regulation, anti-inflammatory actions.
-ACTH is released in periods of stress (trauma, surgery, intense exercise)
HPA Axis
Binds receptors in sweat glands, alimentary tract (GI), distal convoluted tubule of the kidney; major regulator of extracellular fluid volume & K homeostasis; RAAS system
Mineralocorticoids (Aldosterone)
Abnormal adrenal cortex function may render inability to appropriately respond in periods of stress (surgery) and critical illness!
This is bad
-Prolonged excess of cortisol (long term steroid use)
-Pituitary & adrenal adenomas
-Ectopic ACTH-secreting tumors
Cushing Syndrome
Due to the pituitary gland secreting excessive ACTH
Cushing’s Disease
S/sx:
-obesity/OSA (moon face/buffalo hump), HTN w/ volume overload, electrolyte imbalance (K), metabolic derangements (glucose intolerance), GERD, myopathy/weakness/bruising, susceptibility to infection & poor wound healing
Cushing Syndrome
-ECG and electrolyte panel will show Hypokalemia, hyperBG, LVH, and ischemia
Tx: treat HTN, normalize intravascular volume, diuresis with spironolactone, correct electrolytes and BG, conservative use of NMB with skeletal muscle weakness, full reversal of NMB needed before extubation, use etomidate, airway, IV access, and positioning (Obestity/OSA)
Cushing Syndrome
Why use etomidate with Cushing Syndrome?
Inhibits steroid synthesis
Due to the destruction of the adrenal gland
-Autoimmune adrenalitis, TB, tumor, surgery, HIV, radiation
Primary Adrenal Insufficiency
Due to the anterior pituitary gland failing to secrete sufficient ACTH.
-Autoimmune adrenalitis, TB, tumor, surgery, HIV, radiation
Secondary Adrenal Insufficiency
Due to processes that interfere with the release of ACTH.
-Exogenous high-dose glucocorticoid therapy leads to reduced adrenal cortisol synthesis in response to stress
-Prednisone >20 mg/day for >3 weeks
Tertiary Adrenal Insufficiency
Adrenal hormones that modify the effect of catecholamines on vascular tone - can cause hypotension refractory to vasopressor therapy and fluid resuscitation during periods of stress.
Glucocorticoids
S/Sx: fatigue, loss of appetite, wt loss, abdominal pain, N/V, myalgias, hypoBG, hypoNa, hyperK, orthostatic hypotension, hyperpigmented skin
Adrenal Insufficiency
-Determine electrolytes & manage BG (K & Na)
-If suspected, give supplemental steroids
-Myopathy: Skeletal muscle weakness: conservative approach to NMB d/t increased sensitivity, respiratory insufficiency post-op
-Can be refractory to vasopressor therapy & fluid resuscitation, anticipate hypovolemia
-Continue glucocorticoid/mineralocorticoid drug therapy on day of surgery
-AVOID etomidate
-Steroid supplements advisable for major procedures in patients taking >20mg/day of prednisone
Anesthesia Considerations for Adrenal Insufficiency
Patients are at an increased risk of AI for ____ after high-dose corticosteroid therapy due to the suppression of hypothalamic-pituitary-adrenal axis
1 year
Patients taking >20 mg/day of steroids need supplementation during major surgical procedures.
-Hydrocortisone 25mg IV at induction + hydrocortisone 100mg over 24 hrs
Minor (25 mg), Moderate (50-75mg), Severe (100-150mg)
Corticosteroid Stress Dosing
Catecholamine-secreting tumors that originate from chromaffin cells of adrenal medulla.
Triad of S/Sx: Headache, Diaphoresis, and Tachycardia (paroxysmal HTN)
Pheochromocytoma
Diagnosed via plasma-free metanephrines, urinary fractionated metanephrines (broken down catecholamines), CT scan of abd (tumor on adrenals)
-ECG, ECHO, Chest XR, electrolyte panel, BG, CBC
Pheochromocytoma
S/Sx: tachycardia, palpitations, HTN, angina, hx MI, dyspnea, orthopnea, CHF, orthostatic hypotension, headache, diaphoresis, feelings of apprehension, abd pain, nausea, malnutrition, GI bleeding, diarrhea → avoid abd palpation bc it could precipitate a crisis
Pheochromocytoma
-Outpatient: alpha blockade initiated 10-14 days prior to surgery
-Beta blockade after alpha blockade (don’t want to do Beta first due to risk of failure)
-Day of Surgery: aggressive hydration, take all BP meds DOS, expect major hemodynamic changes (A-line, vasoactive meds, plan for post-op care, IV access, prefer less invasive)
Anesthesia Considerations for Pheochromocytoma
Hormones are synthesized here:
-TSH, ACTH, FSH, LH, GH, PL
-More likely to have adenomas (non-cancerous)
Anterior Pituitary
Secretes hormones synthesized in the hypothalamus
-Oxytocin, ADH, and Endorphins
-More likely to have metastatic tumors
Posterior Pituitary
Results from excess growth hormone (stimulates overgrowth of skin, connective tissue, cartilage, bone, viscera).
S/Sx:
-airway abnormalities (macroglossia, vocal cord dysfunction, overgrowth of tissue), soft tissue hypertrophy (macrognathia (enlarged jaw), enlarged nose, facial structures, hands/feet), OSA, Visceromegaly (VQ mismatch), HTN, CAD, Valvular dz, Heart failure, Headache, Papilledema, Visual impairment, DM, Arthropathy/arthralgia, Fractures (positioning implications)
Acromegaly
