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Flashcards in Steroids Deck (26)
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1
Q

what are adrenocortical steroids?

A
  • produced and released by the adrenal cortex
  • secretion controlled by the pituitary release of corticotropin (ACTH)
  • two main classes: mineralocorticoids and glucocorticoids
2
Q

where are mineralocorticoids secreted from?

A

the zona glomerulosa

3
Q

where are glucocorticoids secreted from?

A

the zona fasciculata

4
Q

describe mineralcorticoids and effects

A
  • 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
5
Q

what stimulates secretion of mineralocorticoids?

A
  • increased serum potassium
  • hyponatremia
  • ACTH
  • Angiotensin II
6
Q

describe glucocorticoids

A
  • cortisol responsible for 95% of activity
  • essential for life
  • not stored anywhere in body
7
Q

what are physiologic effects of cortisol?

A
  • 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)
8
Q

what stimulates cortisol secretion? What stops cortisol secretion?

A

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
9
Q

describe cortisol release in the body

A

-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

10
Q

how long does cortisol last in the body?

A
  • 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
11
Q

which drugs are synthetic corticosteroids?

A
  • prednisolone
  • prednisone
  • methylprednisolone acetate (Depo-Medrol)
  • methylprednisolone sodium succinate (Solu-Medrol)
  • betamethasone
  • dexamethasone
  • triamcinolone
12
Q

which drugs are endogenous corticosteroids?

A
  • cortisol, hydrocortisone (Solu-Cortef)
  • cortisone
  • corticosterone
  • desoxycorticosterone
  • aldosterone
13
Q

what are the effects of synthetic corticosteroids?

A
  • 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
14
Q

when is steroid coverage needed?

A
  • 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
15
Q

what are signs and symptoms that steroid coverage is needed?

A
  • unexplained vasopressor-dependent refractory hypotension (BP low for no explanation and only responds to vasopressor)
  • hypovolemic shock with myocardial and vascular unresponsiveness to catecholamines
16
Q

when should it be assumed that steroid coverage is needed?

A
  • 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
17
Q

what are the benefits of steroid coverage?

A

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

18
Q

what are the risks of steroid coverage?

A
  • altered wound healing
  • altered glucose metabolism (diabetics)
  • limited effect if high dose steroid coverage is for a short time
19
Q

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

A
  • usual morning dose OR

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

20
Q

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

A
  • 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
21
Q

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

A

-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

22
Q

what are pharmacologic effects on cortisol levels?

A
  • 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
23
Q

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

A
  • methylprednisolone (Solu-Medrol) 4 mg
  • dexamethasone (Decadron) 0.75 mg
  • prednisone (Deltasone) 5 mg
24
Q

what are some clinical uses of corticosteroids?

A
  • 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
25
Q

how are corticosteroids used as antiemetics?

A
  • unknown mechanism for antiemetic effect
  • dexamethasone (Decadron) 0.5 mg/kg
  • enhances effectiveness of 5-HT3 antagonists (6-10 mg)
26
Q

what are side effects of chronic corticosteroid therapy?

A
  • 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!!