Endocrine Flashcards
What it the typical presentation of Hyperthyroidism?
Feline older than 8 years
excessive production of thyroxine
unilateral or bilateral adenomatous hyperplasia
What are the clinical signs associated with hyperthyroidism?
Irritable Anorexic weight loss Polyphagia PU/PD Vomiting/ diarrhoea Goitre heart disease -hyperthrophic cardiomyopathy -tachycardia Kidney disease -chronic renal insufficiency -can be masked by hyperthyroidism
What are the three options of treatment for Hyperthyroidism?
Medical management
Surgical removal
Radiotherapy
How is a thyroidectomy carried out?
Stabilise with medical management first
Removal of one or both of the thyroid glands
preservation of the parathyroid tissue
What post-operative care should be considered in the hyperthyroid cat?
Fluid therapy analgesia Monitor kidney problems(can arise once metabolism lowered after removal of the thyroid) Monitor hypocalcemia laryngeal paralysis Horners syndrome Recurrent hyperthyroidism hypothyroidism
What is hypocalcemia and how should it be monitored in the hyperthyroid cat after surgery?
Look at the calcium levels in the blood lower than normal
monitor 2-7 days after surgery check ionized calcium levels
What are the clinical signs of Hypocalcemia?
Muscle twitching
Facial pruitis
Seizsures
What is the treatment of hypocalcemia?
10% calcium gluconate 0.25-1.5ml/kg slow iv over 10-20 minutes
maintained on a calcium drip 10ml/10% calcium gluconate in 250mls of hartmanns solution at 60ml/kg over 24 hours
oral vitamin D and calcium
taper medication over 4-10 weeks, monitor ionized calcium
Describe the anatomy of the parathyroid glands?
Above the thyroid glands two glands either side
secrete parathyroid hormone
increases calcium concentration in the blood and decreases phosphorus
What are the typical presentation of parathyroid tumours?
Older dog
Adenoma or adenomatous hyperplasia
causes increased secretion of parathyroid hormone and loss of normal inhibition- primary hyperparathyroidism
increased calcium levels hypercalcemia
How do you diagnose a parathyroid tumour?
Hypercalcemia
PU/PD
parathyroid mass on u/s
rule out lymphoma and anal sac adenocarcinoma
How do you treat parathyroid tumours?
Pre-treat, diuresis IVFT saline +/- diuretic
Surgical removal of the mass
parathyroidectomy
Partial thyroidectomy
What are the post-operative care considerations for the parathyroidectomy patient?
Monitor ionized calcium levels (once or twice daily 2-7 days)
Monitor renal parameters
routine fluid therapy and analgesia
How should you treat a post-parathyroidectomy patient that has hypocalcemia?
10% calcium gluconate 0.25-1.5 mg/kg slow iv over 10-20 minutes
Continue on calcium spiked drip 10ml of 10% calcium gluconate in 250mls hartmanns 60ml/kg over 24 hours
Oral vitamin D and calcium
Taper oral calcium over 2-4 months, then vitamin D assuming calcium stable
What is the pancreatic endocrine function?
Beta cells produce insulin
regulates the glucose metabolism
Insulin decreases blood glucose levels and causes storage of glucose
What is an insulinoma?
Carcinoma or adenoma of the pancreas cells
Secretes insulin
aggressive biological behaviour (metastasis)
Causes hypoglycemia
What are the clinical signs of an insulinoma?
Lethargy Improves after feeding Ataxia Seizures Muscle weakness Mild initial onset gradual worsening of symptoms
How is an insulinoma diagnosed?
Mass on u/s
Low blood glucose levels
Fasting blood glucose less than 2.2mmol/l
improvement in signs following feeding or administration of glucose
increase serum insulin
CT
How do you treat and insulinoma?
Sugar solution, glucose iv 0.25g/kg Medical management -frequent meals -glucocortocid steroids -diazoxide
How is the surgery to remove the insulinoma carried out?
Removal of nodule via partial pancreatectomy
5% dextrose infusion to prevent hypoglycemia
monitor glucose peri-operative
post-operative care insulinoma
Monitor glucose transient hypeglycemia persistent hypoglycemia pancreatits (ANALGESIA) 785 days will metastasise aggressive tumour
What is the function of the adrenal glands?
Adrenal cortex -Cortisol production -Aldosterone -sex hormones Adrenal medulla -catecholamines (noradrenaline, adrenaline)
What types of adrenal tumours can you get?
Adenoma/ adenocarcinoma fuctional vs non-fuctional tumours of the adreanl cortex -cushings -conns syndrome (hyperaldosteronism) Tumours of the adrenal medulla Phaeochromocytoma
What do adreoncotical tumours do?
Most common Secrete cortisol Create cushings -PU/PD, pot bellied, lethargy, muscle weakness, alopecia, polyphagia -low dose dexmethasone test
What do phaeochromocytoma cause and what are the clinical signs associated with them?
Release of catecholamines typical signs -generalised weakness -collapse -panting -tachycardia -muscle wasting -intermittent hypertension
How are phaeochromocytoma diagnosed?
U/s mass on adrenal glands
CT
How are adrenocortical tumours medically treated?
Trilostane before surgery
How are phaechromocytoma treated medically?
Phenooxybenzamine 2-3 weeks before surgery (reduces effects of adrenaline)
Propranolol (beta adrenergic antagonist) can help with persistent tachycardia
What are the surgical considerations for adrenocoritcal tumours?
May have delayed healing
pulmonary thromboembolism
What are the surgical considerations for phaechromocytoma?
Surgical manipulation can cause a surge in catecholamine release -hypertension -tachycardia -arrythmias -cardia arrest Close anaesthetis monitoring Propranolol for tachycardia Lidocaine for arrythmias
What surgical approached can you take to remove an adrenal tumour?
Midline
Flank
Laproscopic
What is a risk of adrenal tumour removal?
Haemorrahage
Blood type before surgery
What post-operative care should you consider after adrenal tumour removal?
Fluids and analgesia
Monitor arrythmias
Monitor hypoadrenocortisim
Dogs require steroid supplementation during and after surgery (dexmethasone pre-op, prednisalone post-op)
Supplementation mineralcorticoids
Monitor electrolytes (decreased sodium and increased potassium)
Fludrocortisone
What adrenal tumours are more common in cats and what clinical conditions do they cause?
Adrenocortical conns syndrome hyperaldosetronism increased sodium and water retention hypertension Hypokalaemia episodic muscle weakness collapse
