More Endocrinopathies Flashcards
How can hypocalcaemia be treated prior to anaesthesia?
Slow administration (10-20 mins) of 10% calcium gluconate at a rate of 0.5-1.5ml/kg (or 50-150mg/kg) iv (L&J)
There are often no clinical signs with hyperparathyroidism, but those that show signs, what are they?
PU/PD, lower urinary tract inflammation, calcium containing uroliths, CKD
Hyperparathyroidism can be treated by removing the affected gland. What is a possible post op complication?
Post op hypocalcaemia can occur due to the remaining 3 glands being atrophied by long term exposure to elevated calcium levels.
What is a pheochromocytoma?
A catecholamine (primarily noradrenaline) secreting tumour of the adrenal medulla.
What are the common signs seen with pheochromocytoma?
Weakness, collapse, tachypnoea, tachyarrhythmias, hypertension and seizures.
What is the treatment for pheo?
Treatment with phenoxybenzamine, an alpha -1 adrenergic receptor antagonist (with some alpha 2 activity as well). Usually administered for 1-2 weeks (at optimum dose) prior to surgery for tumour excision. It aims to reduce catecholamine induced hypertension.
Pheoxybenzamine can significantly improve mortality rate.
If beta blockers are required for pre op tachycardia, they should only be given once there has been treatment with phenoxy.
What is the effect of chronic sympathetic (pheo) stimulation on blood vessels?
Chronic vasoconstriction which can result in intravascular volume depletion and so hyrdration status should be assessed and corrected prior to GA.
What drugs should be avoided with pheo?
Drugs with sympathomimetic or vagolytic effects…ketamine, alpha 2 agonists, nitrous, desflurane, anticholinergics. Morphine and atracurium for histamine realease.
What drug protocol can be used for pheo?
Premed and induction with an opioid that doesn’t cause histamine release (methadone, fentanyl - not morphine). A benzodiazepine and propofol or alfaxalone. For pain intraop - fentanyl, remifentanyl.
What are the anaesthesia considerations for pheo?
- Hypertension & post excision hypotension (reduced catecholamines and residual phenoxy effects) - IBP
- Haemorrhage - possible infiltration of vena cava (more so right side)
- Tachyarrhythmias - treat with lidocaine
- Multiple IV access - fluids, blood products, drugs
- Catecholamine spikes during tumour manipulation
- Hypoglycaemia can occur following rapid drops in catecholamines
What are insulinomas?
Insulin secreting malignant tumours of the pancreatic beta cells
What is the recommendation for starving pre GA for insulinomas?
No more than 6 hours as there is risk of hypoglycaemic seizures
Why do you need to be careful about feeding with insulinoma in the pre op period?
Feeding can cause an insulin spike, resulting in worse hypoglycaemia
What is catabolism?
Breakdown of complex molecules into simpler ones, releasing energy
What is anabolism?
Building of complex molecules from simpler ones, requiring energy i.e ATP from catabolic processes
