Steroids

Question 1

what are adrenocortical steroids?

Answer 1

• produced and released by the adrenal cortex
• secretion controlled by the pituitary release of corticotropin (ACTH)
• two main classes: mineralocorticoids and glucocorticoids

Question 2

where are mineralocorticoids secreted from?

Answer 2

the zona glomerulosa

Question 3

where are glucocorticoids secreted from?

Answer 3

the zona fasciculata

Question 4

describe mineralcorticoids and effects

Answer 4

• aldosterone responsible for 95% of activity
• maintains status quo regarding extracellular fluid volume
• maintains plasma concentrations of sodium and potassium
• conserves sodium to attract water into extracellular fluid
• maintains normal concentrations of potassium through excretion in urine

Question 5

what stimulates secretion of mineralocorticoids?

Answer 5

• increased serum potassium
• hyponatremia
• ACTH
• Angiotensin II

Question 6

describe glucocorticoids

Answer 6

• cortisol responsible for 95% of activity
• essential for life
• not stored anywhere in body

Question 7

what are physiologic effects of cortisol?

Answer 7

• increase gluconeogenesis (amino acids to glucose) *^BG
• protein catabolism (less amino acids stored causes muscle weakness if cortisol excessive)
• fatty acid mobilization (movement and oxidation of fatty acids in the cells)
• anti-inflammatory effects (decrease capillary permeability; stabilize lysosomal membranes)
• decreased immune response (decreased movement of leukocytes into inflamed areas; decreased eosinophils and leukocytes; interfere with formation of leukotrienes)
• increased number and sensitivity of beta-adrenergic receptors (*increasing myocardial and vascular response to catecholamine)

Question 8

what stimulates cortisol secretion? What stops cortisol secretion?

Answer 8

ACTH (adrenocorticotrophic hormone) released from anterior pituitary

• stimulation for the secretion of ACTH is from hypothalamic neurohormones (corticotropin-releasing hormone and AVP, arginine vasopressin)
• increased levels of cortisol cause negative feedback on the hypothalamus to decrease the production of corticotropin-releasing hormone and on the anterior pituitary to produce less ACTH

Question 9

describe cortisol release in the body

Answer 9

-daily secretion: 20 mg with more secreted during the day
-stress response: output increased up to 150 mg/day
50 mg/day- minor surgery
75-150 mg/day-major surgery

Question 10

how long does cortisol last in the body?

Answer 10

• elimination 1/2 life is 70 min
• there is NO storage in the body!
• if pt. cant produce cortisol themselves, we must provide steroid coverage

Question 11

which drugs are synthetic corticosteroids?

Answer 11

• prednisolone
• prednisone
• methylprednisolone acetate (Depo-Medrol)
• methylprednisolone sodium succinate (Solu-Medrol)
• betamethasone
• dexamethasone
• triamcinolone

Question 12

which drugs are endogenous corticosteroids?

Answer 12

• cortisol, hydrocortisone (Solu-Cortef)
• cortisone
• corticosterone
• desoxycorticosterone
• aldosterone

Question 13

what are the effects of synthetic corticosteroids?

Answer 13

• anti-inflammatory effect
• immune suppression
• suppression of hypothalamic-pituitary-adrenal (HPA) axis (when body needs to produce more cortisol d/t stress, it cant)
• weight gain
• skeletal muscle wasting

Question 14

when is steroid coverage needed?

Answer 14

• the release of cortisol in response to the stress of surgery is decreased or eliminated
• HPA axis suppression (highly variable; occurs at different doses in different people)
• if taking steroids daily
• larger dose of steroids and longer the therapy, greater likelihood that suppression has occurred
• Critical illness-related corticosteroid insufficiency (CIRCI): adrenal response to stress is inadequate

Question 15

what are signs and symptoms that steroid coverage is needed?

Answer 15

• unexplained vasopressor-dependent refractory hypotension (BP low for no explanation and only responds to vasopressor)
• hypovolemic shock with myocardial and vascular unresponsiveness to catecholamines

Question 16

when should it be assumed that steroid coverage is needed?

Answer 16

• corticosteroid therapy has been used for more than two weeks within the previous year, assume some suppression has occurred
• anyone who has received corticosteroids equivalent to average daily adrenal output (hydrocortisone 20 mg/d) is considered depressed
• anyone who has received hydrocortisone equivalent of more than 20-30 mg daily for longer than two weeks during the previous year
• talk with surgeon and others on anesthesia care team
• keep some in room

Question 17

what are the benefits of steroid coverage?

Answer 17

-prevention of life threatening secondary adrenal insufficiency: cardiovascular collapse, perioperative hypotension

Question 18

what are the risks of steroid coverage?

Answer 18

• altered wound healing
• altered glucose metabolism (diabetics)
• limited effect if high dose steroid coverage is for a short time

Question 19

what are the recommendation for steroid coverage for a minor surgery?

Answer 19

• usual morning dose OR

- preoperative corticosteroid dose (usual morning dose) + hydrocortisone 25 mg (or equivalent)

Question 20

what are the recommendations for steroid coverage for a moderate surgery (colon resection, total joint)?

Answer 20

• hydrocortisone 50 mg IV, then 25 mg every 8 hrs for 24 hrs; then usual daily dose OR
• preoperative corticosteroid dose (usual morning dose) + hydrocortisone 50-75 mg or equivalent

Question 21

what are the recommendations for steroid coverage for a major surgery (CV, thoracic)?

Answer 21

-hydrocortisone 100 mg IV at induction, 50 mg every 8 hrs for 3 doses; then taper rapidly down to daily dose (pediatric 2mg/kg IV)
OR
-preoperative corticosteroid dose (usual morning dose) + hydrocortisone 100-150 mg or equivalent every 8 hrs for 48-72 hrs

Question 22

what are pharmacologic effects on cortisol levels?

Answer 22

• etomidate suppresses the adrenal cortex synthesis of cortisol
• opioids in large doses may reduce the cortisol response to surgical stress
• volatile agents suppress the response to a lesser degree

Question 23

what are equivalent doses of cortisol (hydrocortisone, Solu-Cortef) 20 mg?

Answer 23

• methylprednisolone (Solu-Medrol) 4 mg
• dexamethasone (Decadron) 0.75 mg
• prednisone (Deltasone) 5 mg

Question 24

what are some clinical uses of corticosteroids?

Answer 24

• replacement therapy
• anti-inflammatory effect (prednisone)-palliative, not curative
• cerebral edema (dexamethasone)
• aspiration pneumonitis
• lumbar disc disease
• immunosuppression
• asthma
• antiemetic effect
• arthritis
• collagen diseases
• ocular inflammation
• cutaneous disorders
• postintubation laryngeal edema (decadron)
• ulcerative colitis
• myasthenia gravis
• respiratory distress syndrome
• leukemia
• septic shock
• cardiac arrest

Question 25

how are corticosteroids used as antiemetics?

Answer 25

- unknown mechanism for antiemetic effect * dexamethasone (Decadron) 0.5 mg/kg * enhances effectiveness of 5-HT3 antagonists (6-10 mg)

Question 26

what are side effects of chronic corticosteroid therapy?

Answer 26

- suppression of HPA axis - electrolyte, metabolic changes (distal renal tubules): absorption of Na+, loss of K+, hyperglycemia - fat distribution: buffalo hump, supraclavicular, face, thin extremities (difficult airway?) - osteoporosis: inhibit osteoblasts, activate osteoclasts, decreased calcium absorption - peptic ulcer disease (don't give toradol) - skeletal muscle myopathy - CNS dysfunction: increased neuroses, psychoses, manic depression, suicidal - cataracts (prednisone 20 mg/d x 4yrs) - peripheral blood changes: decreased lymphocytes and monocytes - inhibition of growth: in children, inhibition of DNA synthesis and cell division * *inhaled steroid for asthma in children do not suppress HPA axis or growth!!