Addison's (Hypoadrenocorticism) Flashcards Preview

Endocrinology > Addison's (Hypoadrenocorticism) > Flashcards

Flashcards in Addison's (Hypoadrenocorticism) Deck (16):
1

Causes of adrenocortical insufficiency

  • Iatrogenic exogenous glucocort induced atrophy
  • Infiltrative dz: cancer, mycoses
  • Infarction or hemorrhage
  • Pituitary insufficiency
  • Op'DDD-induced destruction
  • Idiopathic
  • Autoimmune destruction
  • Cosyntropin-rare

2

Relative Hypoadrenocorticism

  • animals in septic shock
  • Animals that don't respond to fluids, etc, but respond to steroids

3

Atrophic Z. Fasciculata

  • Dec cortisol, gluconeogenesis, vessel sensitivity to catecholamines, H2O diuresis, apetite
  • Inc Eos, lymphs
  • Dec cerebration

4

Things that normally stim Aldosterone production

  1. Inc potassium levels
  2. Dec blood pressure

5

Pathophys atrophic Z. Glomerulosa

  • Dec Na, dec vasc volume, dec CO, dec BP, dec GFR
  • Inc K, muscle weakness, abnormal cardiac excitation and conduction
  • Dec Cl

6

DXing Addisons in real world

  • Dog at an ER visit in shock
    • dec capillary refill time
    • barely perceptible pulses
    • dog down and out
    • bradycardia

THINK ADDISONS: Low BP means HR should INC

7

Diagnosis of Adrenocortical Insufficiency

  • Historical and clinical findings
  • Electrocardiographic changes
  • Clinical pathologic findings

8

CS of acute addisonian crisis

  • Hx anorex, lethargy, vx, GI signs
  • Dog presents weak or in collapse
  • Mentally dull
  • bradycardia while hypotensive (dog)
  • weak femoral pulse
  • clinically may look like acute uremic state

9

Random chem findings in Addisons

  1. Hypocholesterolemia
  2. Hypoalbuminemia
  3. Hypercalcemia

10

Lab Dx of Addison's

  • ACTH stim test
  • Na/K < 20 (25)
  • Effect of ACTH on EOS
  • Plasma ACTH levels
  • Cortisol: ACTH ratio
  • Aldosterone: Renin ratio

11

Plasma Aldosterone

  • Low in most dogs with Addison's
  • Low blood levels independent of serum Na and K levels
  • Na and K can be normal despite low aldosterone 
    • independent compensatory mechanisms
  • all 3 cortical zones usually affected in primary Addison's

12

Recumbant patient and we suspect Addison's

  1. Begin IV NaCl
  2. Collect resting serum cortisol
  3. Give Cortrosyn IV
    • synthetic ACTH for ACTH stim test
  4. Give dexamethasone IV
  5. Collect 2nd serum cortisol at 1 hr
    • can then give DOPP or fluronef

13

Addisonian Crisis

Principles of TX

  • Restore volume
    • 0.9% NaCl
  • Provide glucocorticoid
    • pred. Na Succinate or
    • dexamethasone
    • Solumedrol
  • Provide mineralocorticoid (behave like aldosterone)
    • Florinef (PO) or
    • DOCP (SQ)
  • Reverse the hyperkalemia
    • Insulin-dextrose
    • HCO3
    • Cal Glu (1mL/kg)

14

Addison's treatment - lifelong

  • Florinef
    • has both Gluco and Mineralocorticoid affect
  •  Oral NaCl
  • Prednisone
  • DOCP (inplace of Florinef)
    • only has mineralocorticoid effect
    • need to add a glucocorticoid as well
  • Periodic Na/K eval

15

Presentation of Atypical Addison's

  • Chronic lethargy, weakness, poor appetite, weight loss
  • Normal serum Na and K despite low aldosterone
  • Absent to minimal ACTH-induced cortisol response

16

Medical or surgical stress to Addisonian patients

  • requires significant supplemental doses of Glucocorticoids