Anaesthesia for patients with endocrinopathies

Question 1

What should you do before anaesthetising a hyperthyroid cat?

Answer 1

• Stabilise before you anaesthetise!
• Surgery is not without risk (Bleeding, hyper and hypotension, inadvertent removal of parathyroid glands, hypocalcaemia post operatively)
• Minimise stress (gabapentin or trazodone at home, quiet environment, pheromones, careful handling), preoxygenate, premedicate, pre-place cannula
• CKD can be exacerbated after treatment

Question 2

What is a good recipe for premed for a spicy cat with comorbidities?

Answer 2

opioid (methadone), Benzodiazepine (midazolam), alfaxalone (given IV or IM)

Question 3

What drugs should you use in hypothyroid animals?

Answer 3

• Stabilise before you anaesthetise!
• For anaesthesia of an uncontrolled hypothyroid
  ◦ Use short acting drugs
  ◦ Anticipate prolonged recovery & try to avoid and support hypothermia
  ◦ Cardiovascular signs will be common (low HR & contractility)
  ◦ Laryngeal paralysis? (can have difficulty intubating, might be early stages)
• Long period of time to come round from anaesthesia with normal doses
• can be unresponsive to fluid loading

Question 4

How would you approach anaesthesia in hypoadrenocorticism?

Answer 4

• Stabilise before you anaesthetise!
• Unstable dogs cannot mount a stress response
• Therefore, provide exogenous steroids perioperatively (hydrocortisone, dexamethasone or prednisolone)
• Consider postponing elective surgery until stable
• Emergency cases unresponsive to fluids and inotropes (may be Addisonian) – have it as a ddx

Question 5

How would you approach anaesthesia in hyperadrenocorticism?

Answer 5

• Stabilise before you anaesthetise!
• Condition caused by excessive glucocorticoids
• Animals may require GA during treatment
• Prone to hypoxaemia & hypertension - due to high steroids
• Pulmonary thromboembolism can occur - can medicate pre- anaesthesia to reduce clotting
• Thin skin, prone to bruising
• Hepatomegaly & large abdomen - pressure on diaphragm, might affect breathing under anaesthesia, can tilt

Question 6

How would you approach anaesthesia in patients with glucose haemostasis disruption?

Answer 6

DM and insulinoma
* Stabilise before you anaesthetise!
* Aim to avoid hypoglycaemia and prolonged severe hyperglycaemia (ketoacidosis)
* Schedule GA s for the morning
* 25%-50% normal insulin beforehand
* Monitor blood glucose q30-60 mins during anaesthetic
◦ Respond if necessary (glucose, insulin)
◦ rather it was a little hyperglycaemic during anaesthetic
Diabetic patients might be dehydrated, hypovolaemic, or both, especially if fasted or anorexic for long periods of time.