Question | Answer |
These are produced and released by the adrenal cortex and secretion is controlled by the pituitary release of ACTH. | Adrenocortical steroids |
This class of steroids is secreted from the zona glomerulosa and aldosterone accounts for 95% of the activity of this class. | Mineralocorticoids |
This class of steroids is secreted from the zona fasiculata and cortisol accounts for 95% of the activity of this class. | Glucocorticoids |
What stimulates secretion of aldosterone? | increase in serum potassium concentration, hyponatremia, ACTH, Angiotensin II |
What is the function of aldosterone? | maintains extracellular fluid volume by conserving sodium and maintains normal concentration of potassium through renal excretion |
What stimulates secretion of cortisol? | ACTH released from the anterior pituitary |
What stimulates secretion of ACTH? | hypothalamic neurohormones AVP and CRH |
What is the function of cortisol? | increases gluconeogenesis, protein catabolism, fatty acid mobilization, anti-inflammatory, decreases immune response, increases number and sensitivity of beta-adrenergic receptors |
What is the normal function of the hypothalamic-pituitary-adrenal axis? | increased cortisol levels in the blood is sensed by the negative feedback system in the hypothalamus; the hypothalamus then secretes less CRH/AVP, which in turn means the pituitary will release less ACTH, resulting in less cortisol production |
What are the endogenous corticosteroids? | cortisol (hydrocortisone, solu-cortef), cortisone, corticosterone, dexoxycorticosterone, aldosterone |
What dose of methylpredisolone (solu-medrol) is equivalent to 20 mg of cortisol (hydrocortisone/solu-cortef)? | 4 mg |
What dose of dexamethasone (decadron) is equivalent to 20 mg of cortisol (hydrocortisone/solu-cortef)? | 0.75 mg |
What dose of prednisone (deltas one) is equivalent to 20 mg of cortisol (hydrocortisone/solu-cortef)? | 5 mg |
Explain why the HPA axis is suppressed with chronic steroid therapy. | Hypothalamic negative feedback system detects steroid in the blood due to corticosteroid therapy. CRH and ACTH production stops, meaning no endogenous cortisol is produced and the body is unable to produce a "stress dose" of cortisol |
When is steroid coverage needed for surgery? | when steroid therapy has suppressed or depressed the HPA axis or presence of CIRCI in critically ill patients |
What are the benefits of steroid coverage in surgical patients with HPA axis depression or suppression? | prevention of life threatening secondary adrenal insufficiency (CV collapse, preoperative hypotension) |
How much corticosteroid does the body secrete daily? | 20 mg daily with more secreted during the day and less at night |
How much corticosteroid does the body secrete for a stress response? | 150 mg daily |
What is the elimination 1/2 life of corticosteroids secreted by the adrenal gland? | 70 minutes - they are NOT stored anywhere |
What are some effects of synthetic corticosteroids? | anti-inflammatory, immune suppression, HPA axis suppression, weight gain, skeletal muscle wasting, delayed wound healing, gastric ulcers, electrolyte disturbances |
What are the signs and symptoms of CIRCI (critical illness-related corticosteroid insufficiency) | unexplained vasopressor-dependent refractory hypotension, hypovolemic shock with myocardial and vascular unresponsiveness to catecholamines |
Is prediction of HPA suppression a black and white issue that does not vary from patient to patient? | NO!!!! highly variable from patient to patient; however, the larger the dose and the longer the therapy the more likely; recovery after stopping glucocorticoids can't be predicted: as little as 2-5 days or as long as 9-12 months |
True or False: if steroid therapy lasted 1 weeks or less, stress dose is not required as HPA function recovers within 1 week, according to some studies. | True |
True or false: when corticosteroid therapy has been used for more than two weeks within the previous year, it is assumed that some suppression has occurred | True |
Anyone who has received corticosteroids equivalent to the average daily adrenal output is considered depressed. What is this average daily output? | hydrocortisone 20 mg/day or equivalent dose |
For minor surgery, what are the two options for steroid coverage dosing? | usual home dose OR home dose + 25 mg hydrocortisone or equivalent |
For moderate surgery, what are the two options for steroid coverage dosing? | Hydrocortisone 50 mg IV, then 25 mg Q 8 x 24 hrs, then home dose OR home dose + hydrocortisone 50-75 mg or equivalent |
For major surgery, what are the two options for steroid coverage dosing? | 100 mg hydrocortisone at induction, 50 mg Q 8 x 24 hrs; then taper to home dose OR home dose + 100-150 hydrocortisone or equivalent Q 8 x 48-72 hours |
What are some examples of moderate surgery stress? | lower extremity revascularization, colon resection, total joint |
What are some examples of major surgery stress? | CV surgery, thoracic surgery, aortic aneurysm repair |
What are 3 drugs possibly used during anesthesia that can reduce or suppress the cortisol response to surgical stress? | etomidate, opioids (large doses), volatile agents (least offender) |
Which corticosteroid possesses as unknown mechanism for antiemetic effect? What dose would you use for this? | dexamethasone (decadron) 0.5 mg/kg (best if given prior to induction) |
What dosage of decahedron enhances the effectiveness of 5-HT3 antagonists? | 6 - 10 mg |