HypO adrenocorticism Flashcards
What is CIRCI
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)
What is delta cortisol?
Difference between pre and post ACTH cortisol
Pathophysiology of Hypoadrenocorticism, what 2 forms exist?
> 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
Which breeds are PDF Hypoadrenocorticism ?
- standard poodles (females,
2 broad clinical pictures of Hypoadrenocorticism LOOK UP
> 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+
-
Clin path findings with Hypoadrenocorticism
> 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 does Hypoadrenocorticism affect electrolytes
- low Na
- high K
> not all cases with v Na ^ K have Hypoadrenocorticism
> Na:K ratio, look for ratio
What is seen in typical Hypoadrenocorticism
- absence of stress leuckogram
- hyponatraemia
- hyperkalaemia
What is seen with atypical Hypoadrenocorticism
- absence of stress leucogram
- normal Na and K levels
- most recently tested atypical patients also have normal aldosterone
- something about study at RVC
Why is Hypoadrenocorticism important to detect?
- 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 much does an ACTH stim test cost?
£8
How can Hypoadrenocorticism be diagnosed
- 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 ***
Tx acute Hypoadrenocorticism
- 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 much is a 24hr Tx of hydrocortisone sodium succinate ?
£3 (more than dex but not expensive!)
What is Hypoadrenocorticism
- 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