Anesthesia for Endocrine Disorders Flashcards
what is required before emergency anesthesia of a DKA patient
agressive fluid replacement
regular insulin therapy
dextrose and potassium supplementation
T/F DM patients should be scheduled first thing in the morning and not fasted prior to anesthesia
False
they should be scheduled first thing, but they need to be fasted for 8-12 hours and given 1/2 normal insulin dose
what should be checked before induction of a DM patient
blood glucose
treat hypoglycemia as needed - verify normoglycemia before administering anesthetic drugs
which class of drug should be avoided in DM patients
alpha 2 agonists
can cause hyperglycemia via inhibition of insulin release or stimulation of glucagon release
what drug protocol should be used for DM patients
short-acting drugs or those that can be reversed
goal is to resume normal feeding and insulin schedule ASAP
how often should blood glucose be check while under anesthesia
q 30-60 min (depends on initial values)
blood glucose should be maintained between ___________mg/dl
150-250 mg/dl
what fluids should be used in DM patients
1-5% dextrose in balanced electrolyte solution as needed (NOT D5W)
have 2 bags prepaired - one with dextrose and one without (used for bolus)
How often should BG be check post op in DM patients
q 1-2 hours until patient is eating
continue fluids with dextrose PRN
why do you not want to over supplement dextrose in insulinoma patients
high blood glucose stimulates insulin release from the tumor
patients are adapted to low BG
where should you keep blood glucose in insulinoma patients
>50 mg/dl
T/F adding glucocorticoids may be necessary to maintain BG in insulinoma patients
True
what should you consider giving if you are unable to maintain BG with dextrose and glucocorticoids in insulinoma patients
glucagon
promotes gluconeogenesis and glycogenolysis
what drugs are contraindicated in insulinoma patients
none - no specific contraindications
what should be monitored before induction and q 1 hour if abnormal in DI patients
Na
maintain <160 mEq/L
what happens if Na is increased/decreased faster than 0.5 mEq/L/hour
may cause fatal brain damage (central pontine myelinolysis)
DO NOT DO THIS…..EVER!
__________ fluids should be used as necessary in DI patients
hypotonic
- 5% dextrose in water (D5W)*
- 0.45% NaCl + 2.5% dextrose*
bradycardia, hypothermia, and hypoventilation are more likely in which patients
hypothyroid
drug protocol for hypothyroid animals
conservative doses
reversible drugs
no specific contraindications
why might hyperthyroid animals have a murmur and/or gallop on auscultation
thickened myocardium - thyrotoxic cardiomyopathy
what is possible in hyperthyroid cats that causes an increase in HR, BP, arrhythmias, and hyperthermia
“Thyroid storm” - catecholamine release
how should hyperthyroid animals be treated pre-op
stabilized before elective procedures
minimize stress
Tx of hyperT may unmask renal disease
why should ketamine and routine anticholinergics be avoided in hyperT patients
increase HR, myocardial work, and O2 consumption
anticholinergics should NOT be withheld in bradycardic patients
which drugs can cause significant CV changes and should be avoided in hyperT patients
acepromazine
alpha 2 agonists
why should mask/chamber induction be avoided in hyperT patients
high stress
what can be used to manage HR in hyperT patients
opioids and benzodiazepines
if a hyperT patient is normally hypertensive or has renal compromise, MAP should be kept at ________
>70 mmHg
kidneys used to higher MAP and are less able to compensate for anesthesia induced hypotension (impaired autoregulation)
what can be used for BP support in hyperT patients
dopamine
what should be decreased before anesthesia in hyperPTH patients
serum iCa
Fluid therapy with 0.9% NaCl, Diuretics, Steroids
marked, chronic hyperCa can lead to ________
ventricular arrhythmias
rapid development of V fib possible at the time of induction
what drugs should be avoided in hyperPTH
long-acting
significant CV effects
what frequently happens post-op with hyperPTH patients
hypoCa
monitor in hospital, Tx with Ca gluconate and PO calcium PRN
how recent should bloodwork be preformed in addisonian patients
<24 hours pre-op
primary concern = BG and lytes
T/F PO gluco- or mineralocorticoids should be discontinued the morning of Sx
False
continue administering scheduled PO gluco- or minalocorticoids
what should you consider giving at time of induction of addisonian patients
physiologic dose of steroid IV
0.1-0.2 mg/kg prednisone equivalent
which drug should be avoided with addisonian patients
Etomidate
causes adrenocortical supression
how should addisonian patients be monitored
no additional monitoring needed in well controlled patients
treat and monitor hypoGLU or lyte abnormalities as indicated - hyperK, hypogGLU, or fluid deficit should have been corrected BEFORE induction
post-op protocol for addisonian patients
restart chronic PO steroids ASAP
monitor for signs of adrenal insufficiency
recheck BG and lytes PRN - based on clinical signs
what are some signs of adrenal insufficiency
vomitting, diarrhea, inappetance
lethargy, weakness
how should abnormal BG and lytes be treated in post-op addisonian patients
give injectable steroids or increase PO steroids until stable
what are some clinical issues in cushing’s patients that have an effect on anesthesia
hypertension - loss of autoregulatory control, keep BP higher
hypercoagulability - susceptible to PTE or thrombosis
hepatomegally - pressure on diaphragm→hypoventilation
poor immune function and wound healing
values obtained pre-op in cushings patients
serum CHEM and CBC
baseline BP
what can indicate a PTE in cushing patients
sharp drop in EtCO2
post- op care of cushing patients
patients on adrenal suppressive Tx (trilostane) may develop adrenal insufficiency d/t stress
consider low-dose steroid Tx - depends on CS and lab results
what are some of the risks/complications of pheochromocytoma patients undergoing Sx
tumor produces epi and norepi - tacharrhythmiasm hypertension
high vascularity (adhere to vena cava) & potential caecholemine release d/t tumor handling
what should be done pre-op in pheochromocytoma patients
stabilize BP and HR with phenoxybenzamine (long acting alpha antagonist) for several weeks pre-op
beta blockers may be used to control HR
T/F alpha blockaid must be in place before beta blockers can be used
True
if not - beta blockers result in profound vasoconstriction d/t block of beta 2 induced vasdilation (opposing the tumor-induced alpha 1 constrictor effect)
what drugs should be avoided in pheochromocytoma patients
drugs that cause tachycardia or vasconstriction
ketamine, alpha 2 agonists, pre-anesthetic atropine (do NOT withhold from bradycardic patients)
what is the most common beta blocker used and why
Esmolol
short-acting, treats tachyarrhythmias
what is used to treat intraoperative vasoconstriction in pheochromocytoma patients
phentolamine - inj. alpha blocker
what can occur once tumor is removed in pheochromocytoma patients
acute drop in catecholemines →bradycardia and hypotension
may be refractory d/t pre-exisiting alpha +/- beta blockaid
what drugs are used to treat the acute drop in catecholamines post tumor removal in pheochromocytoma patients
dobutamine, ephedrine, phenylephrine
pheochromocytoma patients shoud be hospitalized for _______ post op and have _______ and _______ monitored closely
pheochromocytoma patients shoud be hospitalized for at least 48 hours post op and have ECG and BP monitored closely
T/F phenoxybenzamine should be discontinued post-op in pheochromocytoma patients
True
T/F post-op pheochromocytoma patients may become hypoGLU and BG should be monitored closely
True
