Hyperadrenocorticism Flashcards
What is the effect of hyperadrenocorticism on glucose?
*Insulin Resistance (reduced translocation of glucose
transporters)
* Gluconeogenesis
What is the effect of hyperadrenocorticism on Bone + collagen?
- Reduces bone formation
- Reduces calcium absorption in the intestine.
- Down regulates the synthesis of collagen.
What is the effect of hyperadrenocorticism on amino acids + protein?
- 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
What is the effect of hyperadrenocorticism on wound healing?
- Delayed
What is the effect of hyperadrenocorticism on electrolyte + water balance?
- 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.
What animals get hyperadrenocorticism?
- 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)
What are common signs of cushings?
- Polydipsia
- Polyuria
- Polyphagia
- Panting
- Abdominal distention
- Endocrine alopecia
- Hepatomegaly
- Muscle weakness
- Systemic hypertension
What would be seen on bloods + urine with cushings?
- 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
What are other effects of cushings?
- Reduced T4 + normal TSH
- Increased cPLI + snap PLI w no evidence of pancreatitis
What tests can be done to check for cushings?
- Low dose dexamethasone suppression test - take bloods at 0, 3 + 8 hrs
- ACTH stimulation test
- Urine cortisol creatinine ratio
How can you differentiate between pituitary + adrenal mass?
- Measure ACTH
>45pg/ml in pituitary dependent hyperadrenocorticism
<20pg/ml in Adrenal dependent hyperadrenocorticism - Normal = 20-100pg/ml
How would you treat cushings?
- Trilostane
- Start dose = 2-5mg/Kg once daily or twice daily
How would you monitor cushings treatment?
- Clinical signs
- ACTH stimulation - repeat q 3months for first year then q 6months
What are side effects of trilostane?
- Adrenal necrosis
- Hypoadrenocorticism
- Lack of efficacy
- Vomiting + diarrhoea
If patient has hypertension, how would you treat?
- Benazepril
- If refractory = amlodipine
What is tx of macroadenoma?
- Hypophyesctomy
- Radiotherapy
Can you do surgical exicison of cushings masses?
- Adrenal tumours = if not invading renal vein or vena cava
- high morbidity but can cure
- Pituitary tumours = survival improving
What is the aetiology of addisons (hypoadrenocorticism)?
- 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
What animals are disposed to hypoadrenocorticism?
- Middle aged female dogs
- Nova scotia duck tolling retriever (x10 more common)
- poodle, Gt dane, portugese waterdogs, rottie, WHWT
What are clinical signs of addisons?
- Vague malaise
- Vomiting (haematemesis) and diarrhoea/Melaena
- Lethargy, weakness
- Pu, Pd
- Abdominal pain
- Hypovolaemic collapse
What would you expect on physical exam of addisons?
- Weak pulses
- Increased CRT
- Dehydration
- Bradycardia
- Abdominal pain
- Collapse/syncope
What would be seen on bloods with addisons?
- Mild non-regenerative anaemia
- Mild hypercalcaemia
- Pre-renal azotaemia
- Lymphocytosis +/- eosinophilia
- Na:K ratio <27:1
- Hyperkalaemia and hyponatraemia
- Isosthenuric to hypesthenuric urine
- Acidosis
What are differentials for hyperkalaemia + hyponatraemia?
- 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
What happens to ECGs with addisons?
- Bradycardia
- Tall, narrow T waves
- Prolonged QRS interval
- Decreased P wave amplitude
- Prolonged P-R interval
- Absent P wave
- Complete heart block
- Ventricular arrhythmias
How can you test for addisons?
- Single cortisol = if normal = rules out addisons
- <55nmol/l will detect 100% of addisons (+37% fale positives)
What is Tx of addisons?
- Fluid therapy - v hypovolaemic (EMERGENCY)
- tx hyperkalaemia = dextrose saline + insulin
- dexamethasone sodium phosphate
- prednisolone (if stress) - for life
- DOCP - Desoxycorticosterone pivalate - for life
What can go wrong with treatment of addisons?
- 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
What are signs of phaeochromocytoma?
- anxiety
- tachycardia
- tachypnoea
- vomiting
- diarrhoea
- weight loss
- hypertension (retinal detachment)
How are Phaeochromocytoma diagnosed + treated?
- Dx = Radiography or Ultrasound
- Tx = Radical excision (high risk), antihypertensive medication
What are signs of hyperaldosteronism? Tx?
- PUPD
- weakness
- neck ventroflexion (hypokalaemia)
- hypertension (sodium retention)
- Tx =
- restrict sodium and supplement potassium
- surgical excision
- spironolactone (aldosterone antagonist)
