Hyperadrenocorticism

Question 1

What is the effect of hyperadrenocorticism on glucose?

Answer 1

*Insulin Resistance (reduced translocation of glucose
transporters)
* Gluconeogenesis

Question 2

What is the effect of hyperadrenocorticism on Bone + collagen?

Answer 2

• Reduces bone formation
• Reduces calcium absorption in the intestine.
• Down regulates the synthesis of collagen.

Question 3

What is the effect of hyperadrenocorticism on amino acids + protein?

Answer 3

• Raises the free amino acids in the serum.
• Inhibiting collagen formation
• Decreasing amino acid uptake by muscle.
• Inhibits protein synthesis.
• Reduction of IgA, IgM but not IgE

Question 4

What is the effect of hyperadrenocorticism on wound healing?

Answer 4

• Delayed

Question 5

What is the effect of hyperadrenocorticism on electrolyte + water balance?

Answer 5

• Increases water diuresis, glomerular filtration rate, and
  renal plasma flow from the kidneys.
• Increases renal sodium retention and potassium excretion.
• Increases intestinal sodium and water absorption and
  potassium excretion.

Question 6

What animals get hyperadrenocorticism?

Answer 6

• Medium to older age dogs
• V rare in cats
• PDH = more common in small breeds (pituitary dependent hyperadrenocorticism)
• ADH = more common in large breeds (adrenal dependent hyperadrenocorticism)

Question 7

What are common signs of cushings?

Answer 7

• Polydipsia
• Polyuria
• Polyphagia
• Panting
• Abdominal distention
• Endocrine alopecia
• Hepatomegaly
• Muscle weakness
• Systemic hypertension

Question 8

What would be seen on bloods + urine with cushings?

Answer 8

• Haematology = Neutrophilic leukocytosis, Lymphopenia, Eosinopenia, Thrombocytosis, Mild erythrocytosis
• Serum biochem = Increased ALKP + ALT, Hypercholesterolaemia, Hypertriglyceridaemia, Hyperglycaemia
• Urinalysis = Specific gravity ≤1.018–1.020, Proteinuria, Urinary tract infection

Question 9

What are other effects of cushings?

Answer 9

• Reduced T4 + normal TSH
• Increased cPLI + snap PLI w no evidence of pancreatitis

Question 10

What tests can be done to check for cushings?

Answer 10

• Low dose dexamethasone suppression test - take bloods at 0, 3 + 8 hrs
• ACTH stimulation test
• Urine cortisol creatinine ratio

Question 11

How can you differentiate between pituitary + adrenal mass?

Answer 11

• Measure ACTH
  >45pg/ml in pituitary dependent hyperadrenocorticism
  <20pg/ml in Adrenal dependent hyperadrenocorticism
• Normal = 20-100pg/ml

Question 12

How would you treat cushings?

Answer 12

• Trilostane
• Start dose = 2-5mg/Kg once daily or twice daily

Question 13

How would you monitor cushings treatment?

Answer 13

• Clinical signs
• ACTH stimulation - repeat q 3months for first year then q 6months

Question 14

What are side effects of trilostane?

Answer 14

• Adrenal necrosis
• Hypoadrenocorticism
• Lack of efficacy
• Vomiting + diarrhoea

Question 15

If patient has hypertension, how would you treat?

Answer 15

• Benazepril
• If refractory = amlodipine

Question 16

What is tx of macroadenoma?

Answer 16

• Hypophyesctomy
• Radiotherapy

Question 17

Can you do surgical exicison of cushings masses?

Answer 17

• Adrenal tumours = if not invading renal vein or vena cava
• high morbidity but can cure
• Pituitary tumours = survival improving

Question 18

What is the aetiology of addisons (hypoadrenocorticism)?

Answer 18

• PRIMARY = destruction of >90% of adrenal cortices
• Multiple autoimmune-associated genes may be involved
• SECONDARY = deficient ACTH (trauma, tumour) leading to atrophy of the adrenal cortex
• Primarily cortisol deficiency

Question 19

What animals are disposed to hypoadrenocorticism?

Answer 19

• Middle aged female dogs
• Nova scotia duck tolling retriever (x10 more common)
• poodle, Gt dane, portugese waterdogs, rottie, WHWT

Question 20

What are clinical signs of addisons?

Answer 20

• Vague malaise
• Vomiting (haematemesis) and diarrhoea/Melaena
• Lethargy, weakness
• Pu, Pd
• Abdominal pain
• Hypovolaemic collapse

Question 21

What would you expect on physical exam of addisons?

Answer 21

• Weak pulses
• Increased CRT
• Dehydration
• Bradycardia
• Abdominal pain
• Collapse/syncope

Question 22

What would be seen on bloods with addisons?

Answer 22

• Mild non-regenerative anaemia
• Mild hypercalcaemia
• Pre-renal azotaemia
• Lymphocytosis +/- eosinophilia
• Na:K ratio <27:1
• Hyperkalaemia and hyponatraemia
• Isosthenuric to hypesthenuric urine
• Acidosis

Question 23

What are differentials for hyperkalaemia + hyponatraemia?

Answer 23

• Gastrointestinal disease
• Renal failure (acute or chronic)
• Parasitic infection (whipworms)
• Urinary obstruction
• Chronic effusion with repeated drainage
• Pregnancy
• Congestive heart failure
• Diabetes mellitus
• Chronic blood loss

Question 24

What happens to ECGs with addisons?

Answer 24

• Bradycardia
• Tall, narrow T waves
• Prolonged QRS interval
• Decreased P wave amplitude
• Prolonged P-R interval
• Absent P wave
• Complete heart block
• Ventricular arrhythmias

Question 25

How can you test for addisons?

Answer 25

* Single cortisol = if normal = rules out addisons - <55nmol/l will detect 100% of addisons (+37% fale positives)

Question 26

What is Tx of addisons?

Answer 26

* Fluid therapy - v hypovolaemic (EMERGENCY) * tx hyperkalaemia = dextrose saline + insulin * dexamethasone sodium phosphate * prednisolone (if stress) - for life * DOCP - Desoxycorticosterone pivalate - for life

Question 27

What can go wrong with treatment of addisons?

Answer 27

* Acute renal failure * Myelinosis * Depression, weakness, ataxia, tetraparesis, and decreased sensory perception * Signs occur days later and are often irreversible * Prevention = - Raise sodium no faster than 0.5 mEq/L/h - Dexamethasone may have protective effect - Avoid potent minerallocorticoid therapy during crisis

Question 28

What are signs of phaeochromocytoma?

Answer 28

* anxiety * tachycardia * tachypnoea * vomiting * diarrhoea * weight loss * hypertension (retinal detachment)

Question 29

How are Phaeochromocytoma diagnosed + treated?

Answer 29

* Dx = Radiography or Ultrasound * Tx = Radical excision (high risk), antihypertensive medication

Question 30

What are signs of hyperaldosteronism? Tx?

Answer 30

* PUPD * weakness * neck ventroflexion (hypokalaemia) * hypertension (sodium retention) * Tx = - restrict sodium and supplement potassium - surgical excision - spironolactone (aldosterone antagonist)