Page 2744 - Cote clinical veterinary advisor dogs and cats 4th

Hypoadrenocorticism 1429

Hypoadrenocorticism
VetBooks.ir with hypoadrenocorticism
Clinical signs consistent

Hyperkalemia
and hyponatremia?
Yes No

• If hypovolemic: IV fluid resuscitation with 0.9% NaCl Signs are consistent
30-45 mL/kg over 1 hour, then reassess and administer with atypical
more if necessary; add dextrose if hypoglycemic hypoadrenocorticism
• Begin ACTH stimulation test*
Perform baseline cortisol

Marked hyperkalemia and/or ECG changes due to if >2 mcg/dL if ≤2 mcg/dL
hyperkalemia? If so, consider administration of calcium (55 nmol/L) (55 nmol/L)
gluconate, dextrose ± insulin, or bicarbonate
(see Hyperkalemia, p. 1235).
Normal cortisol; pursue Perform ACTH
other diagnoses stimulation test
Dexamethasone sodium
phosphate (0.25 mg/kg IV)
Stimulation No stimulation

Atypical hypoadrenocorticism
confirmed

Finish ACTH stimulation test
If wish to differentiate 2° versus
early 1° hypoadrenocorticism,
measure endogenous ACTH
• When shock resolved (1 to 2 h), decrease IV fluid rate
to 90-120 mL/kg/d for 1 to 2 days
• Dexamethasone (0.07-0.15 mg/kg IV q 12h)
or predniso(lo)ne 0.5 mg/kg PO q 24h Normal or high endogenous Low endogenous
ACTH concentration ACTH concentration
• Probably early 1° • Secondary
Diagnosis confirmed? hypoadrenocorticism hypoadrenocorticism
No Yes
• Prednisone (0.2-0.25 mg/kg Prednisone
orally q 24-48h; (0.2-0.25 mg/kg
Pursue other Select treatment modality: either oral increase if stressed)
orally q 24-48h;
diagnoses (fludrocortisone) or repositol • Monitor serum K and Na ; if or increase if stressed)
+
+
injectable (DOCP) when mild hyperkalemia occurs,
change to treatment regimen
including both glucocorticoids
and mineralocorticoids Clinical Algorithms
• Fludrocortisone acetate (0.01 mg/kg • DOCP (2.2 mg/kg SQ or IM initially
orally q 12h) q 25 days)
• ± Prednisone orally (may not be • Prednisone (0.2-0.25 mg/kg orally q
needed except when stressed) 24-48h; increase if stressed)
• Recheck electrolytes at 7 and 14 days • Recheck electrolytes at 12 and 25 days

Electrolytes normal? Continue treatment Mild hyperkalemia? Increase dose of
and monitor monthly for 3 to fludrocortisone or DOCP and recheck in
6 months, then q 3-6 months 7 to 12 days
UPDATED AND EDITED BY: Leah A. Cohn, DVM,
PhD, DACVIM
ORIGINALLY WRITTEN BY: Cary L. M. Bassett,
ACTH, Adrenocorticotropic hormone; DOCP, desoxycorticosterone pivalate. DVM, DACVIM
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