HypO adrenocorticism Flashcards

1
Q

What is CIRCI

A

Critical illness related corticosteroid insufficiency
> management of pressor-resistant septic shock (subset of people have relative Hypoadrenocorticism so won’t be able to protect themselves if seriously unwell)
- low dose hydrocortisone -> more rapid pressor weaning regardless of ACTH stim results (don’t need as much pressor stimulation to raise BP)
- BUT no survival benefits and ^ risk superinfections of with hydrocortisone
> doesn’t happen in vet world (we don’t think)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is delta cortisol?

A

Difference between pre and post ACTH cortisol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Pathophysiology of Hypoadrenocorticism, what 2 forms exist?

A

> disorder resulting in clinically significant adrenocorticalysis
- immune mediated
- adrenal haemorrhage d/t ^ ACTH
reduced capacity to produce adrenocortical hormones (cortisol and aldosterone)
- typical = cortisol and aldosterone
- atypical = no electrolyte abnormalities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which breeds are PDF Hypoadrenocorticism ?

A
  • standard poodles (females,
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

2 broad clinical pictures of Hypoadrenocorticism LOOK UP

A

> acute
- collapse, severely compromised
- sudden onset or maybe after relapsing more subtle set of problems
- hypovolaemic and dehydrated
- shock
- may be tachycardic (hypovolaemic) or bradycardic (K+^) or neither
chronic (often presents for GI disturbance)
- subtle, unwell, waxing and waning presence
- non-specific lethargy, depression
- MELEANA (2* structural gut damage)
- VD+
-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Clin path findings with Hypoadrenocorticism

A

> mild mod anaemia
- non-regenerative (ill)
- regenerative (MELEANA)
hypoproteinaemia
- normoproteinemic in a hypovolaemic patient
- panhypoproteinaemia (cf. nephropathy where low weight albumen lost)
eosinophilia, lymphocytosis
- lack of stress leucogram
azotaemia and inappropriately dilute urine (d/t v Na)
hyponatraemia, hyperkalaemia, hypercalcaemia (total and ionised(not well understood))
hypoglycaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does Hypoadrenocorticism affect electrolytes

A
  • low Na
  • high K
    > not all cases with v Na ^ K have Hypoadrenocorticism
    > Na:K ratio, look for ratio
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is seen in typical Hypoadrenocorticism

A
  • absence of stress leuckogram
  • hyponatraemia
  • hyperkalaemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is seen with atypical Hypoadrenocorticism

A
  • absence of stress leucogram
  • normal Na and K levels
  • most recently tested atypical patients also have normal aldosterone
  • something about study at RVC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is Hypoadrenocorticism important to detect?

A
  • Young dogs with fatal disease
  • easy and cheap to Tx
    > but must not start Tx without confirmed dx!
  • exacerbation of compromised organs
  • adverse effects
  • once on meds very difficult to investigate further
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How much does an ACTH stim test cost?

A

£8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How can Hypoadrenocorticism be diagnosed

A
  • ACTH stim best (low cortisol pre and post)
  • basal cortisol necessary baseline (if above 50(?) probably not hypo)
  • **ensure not receiving any form of GC iatrogenically to interfere with test results ***
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Tx acute Hypoadrenocorticism

A
  • parenterally administered medications
  • IV fluids (0.9% nacl) absolutely No more than 7-8ml/kg/Hr
  • adrenocortical hormone replament Tx
    > short acting and GC:MC ratio equal = hydrocortisone sodium succinate
    > NOT DEX (no MC activity, long t1/2, too potent)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How much is a 24hr Tx of hydrocortisone sodium succinate ?

A

£3 (more than dex but not expensive!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Hypoadrenocorticism

A
  • disorder resulting in marked adrenocorticolysis, often immune mediated
  • > diminished adrenocortical reserve
  • reduced capacity to produce cortisol and aldosterone
  • may or may not be clinical significant
  • a proportion of cases have NO ELECTROLYTE ABNORMALITIES = cortisol only deficiency or relative adrenocortical deficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What rate of hydrocortisone infusion is necessary to Tx acute Hypoadrenocorticism? Where does the GC activity come from?

A

0.5mg/kg/h

+ cortisol in circulation provides adequate GC and MC activity for a seriously stressed dog

17
Q

Clinical signs associated with acute Hypoadrenocorticism (spontaneous cases)

A
  • deroessed, lethargic
  • dehydrated
  • GI signs
  • some bradycardic
  • hyponatraemia
  • hyperkalaemia
  • hypochloremia
  • azotaemia
  • USG
18
Q

Tx acute Hypoadrenocorticism

A
  • IVFT (0.9% nacl 8ml/kg/hr)
  • hydrocortisone sodium succinate (0.5mg/kg/hr IV, 1-2mg/ml)
    > parenterally administered
    > GC:MC equal activity
    > short t1/2, simple, physiological and effect
  • oral Tx once they start eating and drinking (36hrs usually)
  • reduce infusion rate to 0.25mg/kg/h IV
  • stop after further 1-2days
19
Q

How do Na,, K and ACTH levels change with fluid Tx of Hypoadrenocorticism

A
  • sodium increases
  • K decreased
  • ACTH decreased
20
Q

Tx chronic clinical picture of Hypoadrenocorticism

A

> Tx all body systems involved
- GIT (structural gut dz, IBD on biopsy)
- neuromuscular (weakness and lethargy)
- renal dysfunction (azotaemia, inappropriately dilute urine)
medication with appropriately balanced MC and GC activity
- fludrocortisone (mostly MC activity, GC too)
- 50% may need GC supplements (cortisone acetate if 20kg as hard to dose smaller)
- dietary considerations (salt supplementation)
- DCP (only available US, pure MC)
avoid OD with GCs
- try and use least potent GC poss (cortisone)

21
Q

Correct GC dose to supplement a normal dog?

A
  • Normal adrenal production in the dog (0.2mg/kg/day of cortisol)
  • prednisolone has 5x GC activity of cortisol
  • > 10kg dog needs 0.4mg per day in total!!! MUCH LOWER THAN MOST PEOPLE WILL GIVE - tablets very big.
22
Q

What can excessive GC exposure cause?

A
  • pseudomyotonia
23
Q

Eg. Of an excessive GC dose for a 25kg dog

A

Anything over 1mg/kg

24
Q

How much do cortisone acetate and hydrocortisone tablets cost?

A

Cortisone acetate £16/pack 30p/tablet

Hydrocortisone £60/pack £2/tablet

25
Q

How can treatment efficacy be monitored?

A
  • clinical response as overall indicator
  • GC activity evaluated by leukogram (no stress leucogram wanted)
  • MC activity evaluated by Na and K levels
  • ACTH stim test not useful when on Tx d/t cross reaction
  • basal ACTH level maybe useful(?)
26
Q

What drug should be used in critical patients

A

Hydrocortisone

27
Q

Once stable, which GC drug should be used

A

Cortisone acetate (esp small dogs)