Popular but often unnecessary test
- – perform at any time of day or night
- – obtain blood sample for baseline (random) plasma cortisol level
- – give synthetic ACTH IV (Cosyntropin) 250 ug X11
- – repeat plasma cortisol 1 hour after injection
ADRENAL SUPPRESSION:
- Random cortisol <10 ug/dL OR
- Increment in plasma cortisol <9 ug/dL after ACTH
APPROACH
- – check random plasma cortisol
- – if >=35 ug/dL – likely normal or adequate adrenal function
- – if <10 ug/dL – evidence of adrenal suppression
- – if 10-34 ug/dL – do rapid ACTH stim test as above
** In septic shock, do not check cortisol levels – trial of IV hydrocortisone is recommended if hypotension refractory to volume resuscitation.
Reference:
Marino, P. (n.d.). The ICU book.
Peripheral Brain 