7 - Cushings Part 2 Flashcards
What diagnostic test can function as a screening test and cushings test
B?
When would cushings have no clinical signs
Elevated liver enzymes
How to rule out exogenous steroids
Skin creams, allergies pill
Discontinue all steroids for how long before cushings test
24 hours
If your are trying to test the HPAA for cushing u should be off corticosteroids for
4 - 6 weeks
How to prepare patient for cushings test
Low stress, and fasting if possible
What steroid does not mess with cortisol measurement
Dexamethasone
Screening test for cushings
UCCR, ACTH stimulation , LDDST
Differential test for pituitary or adrenal
LDDST, HDDST, abdominal ultrasound, brain CT
Best test for suspecting cushings
LDDST
LDDST is less
Specific - may be false positive
If ACTH is positive -
Can believe it more if negative you can’t rule it out
How much more Dex is given in Low versus high
10x as much
HDDST cannot replace
LDDST - can get false negatives
What is the gold standard for differentiation
Endogenous ACTH levels
Sensitivity
Ability to accurately detect all dogs with cushings
High sensitivity =
Few false negatives
Specific
Positive test is definitely diagnostic of cushings
High specifics =
Few false positives
Very specific does it rule diagnosis in or out
In
UCCR
Urine cortisol to creating
UCCR is sensitive or specific
Sensitive
Don’t run UCCR when
Patient is super stressed
UCCR indicates
Blood level over time
Is UCCR specific
No
UCCR is good at saying
It is not cushings
What value suggest cushings with UCCR
High
ACTH stimulation testing the
Adrenal glands
Gold standard test for adrenal reserve
ACTH stimulation
Adrenal reserve
How much cortisol can you make
ACTH stim test
Collect baseline sample, give ACTH, 1 hour later
ACTH test what feedback loop
Positive
Gold standard for DX iatrogenic cushings disease
ACTH
What is diagnostic of cushings disease with ACTH stim test
Excessive response
What do you use to monitor therapeutic response
ACTH test
ACTH reliable in cats
no
LDDST test
Adrenal/pituitary response to negative feedback
LDDST - a normal dog should
Spurred
Normal dog suppresses at ___ with LDDST
4 hour and 8 hour
With LDDST, ADH no suppression at
4 hour sand 8 hours
With LDDST, PDH there is
40% no suppression at 4 hours and 8 hours, 60% suppression at 4 hours
What is the test of choice for cushings
LDDST
Basal serum cortisol has little value in DX of
PDH
With PDH what are teh ACTH levels
High
With ADH what are the ACTH levels
Low
Endogenous acth high
PDH
If endogenous act is high and LDDST is diagnostic for cushings what do you know
PDH
