Hypoadrenocorticism

Question 1

pathophyiology

Answer 1

immune-mediated disease resulting in severe adrenocorticolysis
generally all parts of the adrenal cortex are affected
diminished adrenocortical reserve – reduced capacity to produce cortisol and aldosterone
mucosal damage of the GIT
impaired muscle function
impaired cardiovascular integrity
disrupted nutrient homestasis
impaired Na/K exchange in the DCT
hypovolemia

Question 2

signalment

Answer 2

young to middle aged dogs
uncommonly middle aged cats
twice as common in females as males regardless of neutering status - dog

Question 3

2 main clinical presentations

Answer 3

acutely collapsed severely compromised

variably subtle, unwell animal

Question 4

acutely collapsed severely compromised

Answer 4

may be sudden onset or maybe after a relapsing
more subtle set of problems
usually hypovolemic and/or dehydrated
poor circulatory integrity (“in-shock”)
may be tachycardic, bradycardic or neither

Question 5

non-acute form - clinical signs

Answer 5

waxing and waning “not doing well “ type signs 
lethargy, depression, under-responsive 
reduced enthusiasm for exercise 
weakness 
inappetence 
vomiting and/or diarrhoea 
melena 
heart rate usually unaffected - can have bradycardia

Question 6

typical clinical pathology

Answer 6

mild to moderate anemia
hypoproteinemic
normoproteinemic in hypovolemic patients
eosinophilia and/or lymphocytosis or – lack of a “stress leukogram”
azotemia and inappropriately dilute urine
hyponatremia
hyperkalemia

Question 7

stressed leukogram

Answer 7

incr neutophils + monocytes

decr lymphocytes + eosinophils

Question 8

serum sodium and potassium levels

Answer 8

hypoadrenocorticism tends to result in low serum sodium & high serum potassium but not specific to hypoadrenocorticism

Question 9

untreated hypoadrenocorticism - end result

Answer 9

death

Question 10

over-diagnosing effects

Answer 10

exacerbation of already compromised organs
meds with adverse effects
once on these meds it is v.difficult to investigate things further

Question 11

diagnosis

Answer 11

ACTH stimulation test with demonstration of subnormal levels of cortisol before and after ACTH
confidence that no prior glucocorticoid therapy could be interfering with the test results

Question 12

Acute hypoadrenocorticism - Treatment

Answer 12

parenterally administered meds
intravenous fluids:
adrenocortical hormone replacement – short acting -equally glucocorticoid and mineralocorticoid active
hydrocortisone sodium succinate

Question 13

what happens when hydrocortisone is infused IV

Answer 13

amount of cortisol present in the circulation provides adequate amounts of glucocorticoid and mineralocorticoid activity for a seriously stressed dog

Question 14

Hydrocortisone

Answer 14

parenterally administered
equal levels of glucocorticoid and mineralocorticoid bioactivity
short half-life
simple, physiological, effective

Question 15

Acute hypoadrenocorticism - therapy

Answer 15

start and maintain on IV fluids– parenteral NaCl
hormone supplementation – hydrocortisone infusion
oral treatment once they start eating and drinking (usually within 36 hours)
reduce infusion rate, stop after further 24 – 48 hours

Question 16

hypoadrenocorticism - chronic therapy - drugs

Answer 16

fludrocortisone 
deoxycorticosterone pivalate 
cortisone acetate 
prednisolone 
dietary considerations 
need to avoid overdosing with glucocorticoids

Question 17

florinef

Answer 17

synthetic adrenocortical steroid possessing very potent mineralocorticoid properties and high glucocorticoid activity

Question 18

With florinef do I need a glucocorticoid?

Answer 18

almost enough glucocorticoid needed for general maintenance

supplement with least glucocorticoid possible

Question 19

monitoring treatment efficacy

Answer 19

clinical response as an overall indicator is paramount
glucocorticoid activity evaluated by – leukogram
mineralocorticoid activity evaluated by – sodium & potassium levels
ACTH stimulation test
basal ACTH level