Addison's (Hypoadrenocorticism) Flashcards
1
Q
Causes of adrenocortical insufficiency
A
- Iatrogenic exogenous glucocort induced atrophy
- Infiltrative dz: cancer, mycoses
- Infarction or hemorrhage
- Pituitary insufficiency
- Op’DDD-induced destruction
- Idiopathic
- Autoimmune destruction
- Cosyntropin-rare
2
Q
Relative Hypoadrenocorticism
A
- animals in septic shock
- Animals that don’t respond to fluids, etc, but respond to steroids
3
Q
Atrophic Z. Fasciculata
A
- Dec cortisol, gluconeogenesis, vessel sensitivity to catecholamines, H2O diuresis, apetite
- Inc Eos, lymphs
- Dec cerebration
4
Q
Things that normally stim Aldosterone production
A
- Inc potassium levels
- Dec blood pressure
5
Q
Pathophys atrophic Z. Glomerulosa
A
- Dec Na, dec vasc volume, dec CO, dec BP, dec GFR
- Inc K, muscle weakness, abnormal cardiac excitation and conduction
- Dec Cl
6
Q
DXing Addisons in real world
A
- 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
Q
Diagnosis of Adrenocortical Insufficiency
A
- Historical and clinical findings
- Electrocardiographic changes
- Clinical pathologic findings
8
Q
CS of acute addisonian crisis
A
- 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
Q
Random chem findings in Addisons
A
- Hypocholesterolemia
- Hypoalbuminemia
- Hypercalcemia
10
Q
Lab Dx of Addison’s
A
- ACTH stim test
- Na/K < 20 (25)
- Effect of ACTH on EOS
- Plasma ACTH levels
- Cortisol: ACTH ratio
- Aldosterone: Renin ratio
11
Q
Plasma Aldosterone
A
- 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
Q
Recumbant patient and we suspect Addison’s
A
- Begin IV NaCl
- Collect resting serum cortisol
- Give Cortrosyn IV
- synthetic ACTH for ACTH stim test
- Give dexamethasone IV
- Collect 2nd serum cortisol at 1 hr
- can then give DOPP or fluronef
13
Q
Addisonian Crisis
Principles of TX
A
- 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
Q
Addison’s treatment - lifelong
A
-
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
Q
Presentation of Atypical Addison’s
A
- Chronic lethargy, weakness, poor appetite, weight loss
- Normal serum Na and K despite low aldosterone
- Absent to minimal ACTH-induced cortisol response
