Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

SA dx/tx > Hypercortisolism > Flashcards

Hypercortisolism Flashcards

1
Q

What does Cushing’s syndrome describe?

A

Chronic exposure to excess glucocorticoids (cortisol)

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

What is the glucocorticoid released by the adrenal cortices?

A

Cortisol

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

What is cortisol release controlled by?

A

ACTH release from the pituitary gland

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

What is ACTH release determined by?

A

CRH from the hypothalamus

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

What form of spontaneous HC is most common?

A

Pituitary dependent hypercortisolism (PDH)

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

What type of dogs is PDH more commonly seen in?

A

Small dogs
(mini poodle, dachshund, beagle, boston)

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

Where is the tumor in PDH?

A

Anterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does chronic stimulation by ACTH in PDH cause?

A

Bilateral adrenal enlargement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What breed of dogs are predisposed to AT?

A

German Shepherds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What would the expected endogenous ACTH release be in AT?

A

Very low due to negative feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens to the contra-lateral adrenal gland in AT?

A

Becomes atrophied

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

Cushing’s is:

A

An exam room diagnosis
Must see signs and have appropriate history

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the signs of HC?

A

Polyuria
Polydipsia
Polyphagia
Difficulty jumping
Pot-bellied appearance
Stretching of carpal and tarsal ligaments
Bad hair coat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where would you expect the lowest point of the abdomen to be in a HC patient?

A

The liver
Cranial abdominal organomegaly
Very consistent finding in HC dogs

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

What skin condition would be pathognomonic for HC?

A

Calcinosis cutis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are potential consequences of HC?

A

Chronic infections
Poor healing post injury or surgery
Hypertension
Proteinuria
Pulmonary thromboembolism
Decrepitude
Poor quality of life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Only pursue a work-up for HC if one of the following applies:

A

Owner has a complaint
Clinical impression
Medical issue suggests HC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What findings on a CBC would be supportive of HC in a clinical patient?

A

Stress leukogram (neutrophilia, lymphopenia, monocytosis, eosinopenia)
Hematocrit is often increased
Platelets are often increased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What findings on a chemistry would be supportive of HC in a clinical patient?

A

Elevated ALP is the most consistent finding in dogs (usually 10-20x baseline)
Cholesterol is elevated (~350-380)
(Less consistently: mild elevation in glucose, BUN may be low, elevation in phosphorus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What findings on urine analysis would be supportive of HC in a clinical patient?

A

Urine is usually dilute
UTI is common
Significant proteinuria is common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How long should you discontinue use of oral and topical steroids before adrenal testing?

A

> 72 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How long should you discontinue use of depo shots before adrenal testing?

A

> 4 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

When is the ACTH stim test routinely used for?

A

Monitoring of patients on treatment for HC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What will show an exaggerated response to the ACTH stim test?

A

Dogs with HC, chronic non-adrenal illness, dogs with AT (sometimes - can also be normal or flat line)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why can the ACTH stim test be negative in dogs with AT?

A

The tumor may not have receptors for ACTH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Is the ACTH stim test good for cats?

A

No, very inaccurate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the protocol for the ACTH stim test?

A

Obtain a baseline blood sample, inject 5 micrograms/kg IM of cosyntropin, collect second serum sample after 60 mins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How do you interpret an ACTH stim test?

A

Normal dogs are usually between 7-17 micrograms/dl
Post-ACTH stim cortisol >22 micrograms/dl indicates HC in a dog
A flat line response (pre and post are <5 micrograms/dl) in a dog with signs of HC indicates iatrogenic disease or may be seen in AT

29
Q

What does the LDDST investigate?

A

The feed-back loop between the adrenals and pituitary/hypothalamus

30
Q

If the HPA axis is working appropriately, what should dexamethasone do?

A

Suppress CRF from the hypothalamus thereby stopping ACTH release by the pituitary gland

31
Q

How long should cortisol release by the adrenals be stopped after administering dexamethasone?

A

At least 12 hours

32
Q

With PDH, what should be expected after administration of dexamethasone?

A

Pituitary tumor is transiently inhibited or not affected at all by the dex
Cortisol production is evident at 8 hours post dose

33
Q

With an AT, what should be expected after administration of dexamethasone?

A

No inhibition of cortisol production
Cortisol production continues unchanged over the 8 hours

34
Q

What is the protocol for a LDDST?

A

Obtain a baseline blood sample, inject dexamethasone IV (0.01 mg/kg in dogs; 0.1 mg/kg in cats), collect second blood sample 4 hours later, collect third blood sample 8 hours later

35
Q

What does a baseline cortisol tell you?

A

Nothing

36
Q

How do you interpret a LDDST?

A

Look at the 8 hour value first
<1.4 mcg/dl indicates suppression of the HPA axis
>1.4 mcg/dl indicates HPA axis dysfunction
If the 8 hour value was >1.4 mcg/dl, look at the 4 hour value
<1.4 mcg/dl or <50% of baseline at 4 hours indicates PDH

37
Q

Can you assume a dog has an AT if there is no suppression?

A

No

38
Q

What test is generally regarded as superior to the ACTH stim test in dogs?

A

LDDST

39
Q

What is the test of choice for cats with HC?

A

LDDST

40
Q

What can you determine by a urine cortisol : creatinine ratio?

A

A normal result essentially rules out HC

41
Q

What would you expect to see on ultrasonography of PDH?

A

Bilateral adrenal gland enlargement
Generally, fairly symmetrical
Some nodular changes are common

42
Q

What would you expect to see on ultrasonography of a AT?

A

One large gland
Check for mets and invasion of surrounding structures
May note atrophied gland on the other side

43
Q

What might radiography reveal?

A

AT, 50% are calcified and are visible on a lateral view

44
Q

Does calcification of an AT indicate malignant potential?

A

No

45
Q

What would you expect the endogenous ACTH level to be in PDH?

A

Elevated or normal

46
Q

What would you expect the endogenous ACTH level to be in an AT?

A

Very low or undetectable

47
Q

What is the current standard approach in dogs for PDH?

A

Medical therapy

48
Q

What is the MOA for Trilostane?

A

Reversible enzyme inhibitor
Inhibits 3bHSD

49
Q

What is 3bHSB essential for?

A

Synthesis of cortisol from cholesterol

50
Q

How long does Trilostane last?

A

About 18 hours in most dogs
Administered with food in the morning

51
Q

What is the recommended dosing?

A

Once daily for most dogs
BID in diabetics
BID if the effect wears off too soon (escape at night)

52
Q

What is the recommended daily dose to start with?

A

2-3 mg/kg total daily dose
Round down to nearest capsule size

53
Q

What is the recommended recheck schedule?

A

2 weeks after starting, 2-4 weeks later, 3 months later, and then every 4-6 months long term

54
Q

What should you always do if the dog is unwell on recheck?

A

ACTH stim test

55
Q

What might you see on a chem during a recheck and what does it indicate?

A

Increased potassium, indicates suppression of aldosterone, must decrease trilostane dose

56
Q

If you get a result <0.7 mcg/dl in a post-acth stim cortisol what would you do?

A

Stop trilostane and do not restart until patient shows signs of HC

57
Q

If you get a result 0.7-2.0 mcg/dl in a post-acth stim cortisol what would you do?

A

Stop trilostane for 48 hours, restart at 50% of previous dose

58
Q

If you get a result 2.0-7.0 mcg/dl in a post-acth stim cortisol what would you do?

A

Continue at present dose

59
Q

If you get a result >7 mcg/dl in a post-acth stim cortisol what would you do?

A

Consider a 25-50% increase if patient shows signs of HC

60
Q

If the patient is clinically doing well, what tests might you run to ensure dosing is correct?

A

4 hr post dose cortisol or pre-trilostane cortisol

61
Q

If you get a result >5.5 mcg/dl on a 4 hr post dose cortisol, what would you do?

A

Increase the dose by 25-50%

62
Q

If you get a result >5 mcg/dl on a pre-trilostane cortisol, what would you do?

A

Increase dose by 25-50%

63
Q

If you get a result >3 mcg/dl on a pre-trilostane cortisol with clinical signs, what would you do?

A

Increase dose by 25%

64
Q

What is the most important factor when deciding about dose adjustments?

A

Clinical status

65
Q

What are you going to do if a dog becomes ill on trilostane?

A

Stop trilostane, check electrolytes to rule out adrenal necrosis, do an ACTH stim test to assess adrenal function

66
Q

What are the options for treatment of an AT?

A

Surgery
Medical therapy (Trilostane)

67
Q

What is feline hyperadrenocorticism associated with?

A

Diabetes mellitus

68
Q

What are the clinical signs of HC in a cat?

A

Unlikely to be pu/pd unless diabetic
Eat well but not ravenous
Skin issues are common - FRAGILE
Ventral alopecia
Plantigrade stance
Pot-belly appearance
Folded ear tips (pathognomonic, uncommon)

69
Q

What laboratory changes are common in cats with HC?

A

Variable hyperglycemia
Hypercholesterolemia
NO increase in ALP

SA dx/tx (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions