Ex5 Hormones Flashcards
Normal cortisol secretion daily
20-30 mg
Peak plasma cortisol secretion occurs when
4-8 a.m.
Cortisol is mainly degraded in
liver
cortisol is regulated via a ______ by the _____
negative feedback loop HPA axis (hypothalamic-pituitary-adrenal)
How does stress effect CBG/free cortisol levels?
Decreases CBG
Increases free cortisol
How is the HPA effected during illness?
Stress + circulating cytokines stimulate hypothalamus –> more cortisol
Cortisol concentrations normalize within _____ postop
24hours
Cortisol levels in healthy patient
10% biologically active (free cortisol)
90% bound to CBG
CIRCI
Cortisol secretion is reduced or tissues are not responsive to cortisol
Adrenal Insufficiency - Lab findings
Hyponatremia
Hyperkalemia
Adrenal insufficiency - S/S
Hypotension
Tachycardia
Generalized fatigue/weakness
CIRCI - clinical manifestations
Hypotension
Unresponsiveness to catecholamine infusion
Ventilator Dependence
Diagnosis of CIRCI
- ACTH Stimulation test
- baseline cortisol
- Treat + see result
ACTH Stimulation Test
- baseline cortisol level
- give cosyntropin (synthetic ACTH)
- cortisol level 30 min after cosyntropin
- cortisol level 60 min after cosyntropin
ACTH stimulation test results
Adrenal insufficiency positive if delta = 9 mcg/dL between any level
Disadvantage of ACTH stimulation test
All steroids alter results
*except dexamethasone
Cortisol assays measure
total cortisol
*NOT free cortisol (the one that produces effects)
Low Level - Random Serum cortisol
< 10 mcg/dL
High Level - Random serum cortisol
> 34 mcg/dL
Treatment of decreased random serum total cortisol
Hydrocortisone 100mg IV q8h
random serum cortisol < 10 mcg/dL
Treatment - > 34 mcg/dL random cortisol
do not start glucorticoids
Corticosteroid with no mineralocorticoid potency
Dexamethasone
20 Hydrocortisone/cortisol = ____ Prednisone
5
20 Hydrocortisone/cortisol = ____methylprednisolone
4
20 Hydrocortisone/cortisol = ____ Dexamethasone
0.75
20 Hydrocortisone/cortisol = ____ Fludrocortisone
N/A
When can steroids be d/c’ed?
When vasopressor therapy has decreased/no long in need
How to d/c steroids
< 7 days steroid duration = no taper
> 7d = decrease dose 25% per day
What can cause adrenal insufficiency in a single dose?
Etomidate
Chronic Steroids - suppressed HPA exists
Prednisone > 20 mg/daily (or equivalent) for 3w+
Chronic Steroids - no suppression of HPA
Prednisone < 5mg/daily (or equivalent)
Pt taking mg Prednisone daily, vasopressors are increasing, what is tx?
Hydrocort 100mg IV q8h
Pt taking 4mg Prednisone daily, recovering well from surgery, vasopressors are coming off, tx?
Return to 4mg/daily
Pt taking 7mg Prednisone daily, recovering well from surgery, vasopressors are coming off, tx?
Return to 7mg/daily
Pt taking 7mg Prednisone daily, recovering ok from surgery, vasopressors are increasing, tx?
May consider Hydrocort 100mg IV q8h (burst steroid dosing)
Suggested corticosteroid dose in pt receiving chronic prednisone 5mg/daily - critically ill (sepsis-induced hypotension/shock)
Hydrocortisone 50mg IV q6h
Gradual taper following VS
Suggested corticosteroid dose in pt receiving chronic prednisone 20mg/daily - Bowel Perforation occurs in OR
Hydrocortisone 100 q8
Gradual taper following VS
More surgical stress means what in pt receiving chronic steroids at home?
More steroids needed periop
More baseline steroids taken at home means what in periop setting?
More baseline steroids –> patient needs more steroids for procedure than others who do NOT take steroids at home
Given a case to taper, what should you pay attention to?
Hemodynamic stability, length ( > or < 7days)
AE of glucocorticoids
Hyperglycemia, leukocytosis, increased risk of infxn
Stimulates insulin secretion
Hyperglycemia
Beta-adrenergic agonists
Pt on long acting insulin - what should be investigated prior to surgery?
Last dose given
to avoid hypoglycemia intraop
Insulin aspart duration
2-4h
Insulin Lispro duration
2-4h
Regular insulin duration
6-8h
Who should be monitored closely if given insulin?
Pt with renal injury
Renal failure pt given insulin, what should be monitored?
Length of time of insulin will be prolonged – give dextrose if needed
insulin requirement in Type 1 DM
0.5 - 1 unit/kg/day
Side effects of insulin
- hypoglycemia
2. allergic reaction
Insulin resistance
daily need for > 100 units of exogenous insulin
Metformin should be avoided in
Acute Kidney Injury (SCr>1.5mg/dL)
Risk in OR w/ patients on Metformin
If not d/c’ed 48h prior - risk of lactic acidosis
higher risk if receiving nephrotoxic Rx, IV contrast, low perfusion state
Lactic acidosis treatment
Supportive care
Glyburide
- sulfonylurea
- DOA 1day
- Metabolized via liver, + active metabolites
- Excreted via urine
Glipizide
- sulfonylurea
- DOA .5-1day
- Metabolized via liver, NO active metabolites
- Excreted via urine
Glimepiride
- sulfonylurea
- DOA 1+day
- Metabolized via liver, + active metabolites
- Excreted via urine
Patient with renal injury takes sulfonylurea prior to operation, what to monitor for?
Hypoglycemia (esp if + active metabolites - Glyburide, Glimepiride)
Target perioperative blood glucose
< 180
DKA
Hyperglycemia (BG > 250)
Ketosis (+urine or serum ketones)
Acidosis (pH < 7.30, serum bicarb <18mmol/L, anion gap > 10)
Severe DKA
DKA +
- severe acidemia pH<7, bicarb <10, anion gap >12
- Depressed MS (stupor/coma)
Clinical presentation of DKA
Tachycardia Hypotension Kussmal Respirations Hyperkalemia Polyuria/polydipsia, N/V
HHS
Higher BG than DKA (> 600) - or minimal Ketones Acidodic (pH >7.30, bicarb >18) Serum osmolality > 320 Typically Type II
Tx of DKA/HHS
- Fluids
- Correction of hyperglycemia (IV insulin at large dose)
- Electrolyte (mainly K+) replacement
- Correct acidemia
What should be monitored while replacing fluids in DKA/HHS?
Hypokalemia - realize that insulin will cause serum K+ to decrease. Treat low Potassium before initiating insulin (prevent arrest).
AVOID Rx that drops K+ (i.e. lasix, kayexalate)
primary cause of hypoglycemia in OR
liver/renal injury — prolonged insulin clearance
Tx of hypoglycemia
IV Dextrose 10-20g, repeat BG in 15 min, additional IV dextrose until BG > 70mg/dL
