Endocrine Flashcards
Effects of hyperglycemia
Impaired immune response leading to inc risk of infection, impaired wound healing, dehydration, electrolyte disturbances (hyperK)
Should an MG patient continue their pyridostigmine the morning of surgery?
No clear answer but continuing could help avoid resp difficulties prior to surgery.
The disadvantage however is possibility of prolonged NMB with Sux and developing cholinergic crisis.
How would you evaluate a patient’s Carcinoid?
Functional vs. non-functional
- flushing, diarrhea, bronchospasm, BP swings or palpitations, murmurs
Dx = Urinary 5-HIAA
What are your anesthetic concerns for a patient with Carcinoid?
- Cardiac concerns - right sided heart lesions, heart failure
- Pulmonary concerns - bronchospasm, dyspnea, etc
- Avoid triggering a crisis
- avoid meperidine, morphine, sux, atracurium, mivacurium (histamine)
- avoid fasciculations from sux or vigorous abdominal scrubbing
- avoid exogenous catecholamines - epi, levo, stress, anxiety, pain, hypotension, hypothermia, laryngoscopy
- things high in serotonin/histamine - coffee, cheese, etOH,
How would you evaluate a pheochromocytoma patient’s readiness for surgery?
Volume status - CBC for hemoconcentration
BP trends
SOB or chest pain
EKG - LVH, t-wave and ECHO esp w/ dec energy level (catecholamine induced cardiomyopathy)
Started and alpha 10-14 days–> beta blockers
Roizen criteria
- supine BP <160/90
- orthostatic hypotension <80/45
- EKG w/o ST, T wave changes
- no more than 1 PVC every 5 minutes
How is a Pheo diagnosed?
Plasma metanephrines
Urinary catecholamines
Urinary VMA
What drugs would you avoid in a Pheo?
- Drugs that stimulate tumor cells
- Sux from fasiculations
- Morphine and atracurium from histamine - Drugs that inc sympathetic activity
- atropine, ketamine, ephedrine - Drugs that sensitize myocardium to catecholamines
- halothane, droperidol, metoclopramide, ephedrine —-> HTN
Tx BG 356
? Developed DKA - any N/V, abdominal pain 10U insulin NS fluid replacement Urinary and serum ketones ABG Anion gap Insulin gtt to dec by 75-100 per hour (avoid cerebral edema) Add 5% dextrose at bg250 Replace potassium, mag
Even a short delay to resolve acidosis, hypovolemia and hypokalemia reduce the risk of cardiac arrthymia and hypotension
Flow volume loop for large thyroid mass
Fixed obstruction - flattening of both inspiratory and expiratory limbs
How would you optimize hyperthyroid patient for surgery?
Consult endocrine Continue PTU - inhibits peripheral conversion T4->T3 Administer beta blockade (normal HR) Glucocorticoids (dec conversion of T4) Hydration Normal electrolytes
How would you differentiate between MH, thyroid storm and NMS?
All manifest with tachycardia, hyperthermia and AMS
MH and NMS - metabolic acidosis, profound hypercarbia, muscle rigidity
NMS usually slower development than MH
NMS flaccid paralysis with ND-NMBS
Tx immediately with dantrolene
How would you treat thyroid storm?
Acetaminophen Active cooling Beta blockers Fluids Correct electrolytes PTU Hydrocortisone
Hormones produced by pituitary
ACTH Prolactin GH TSH FSH LH
ADH
Oxytocin
What are the mechanisms of bromocriptine and octreotide
Bromo - D2 agonist inhibits secretion of GH and prolactin
Octreotide - somatostatin analogue that dec release of GH
Systemic manifestations of RA
Pericardial thickening, effusion
Valve fibrosis, ischemia, diastolic dysfunction, nodules cause dysrhythmias
Pleural effusions, pulm fibrosis
neuropathies
liver and kidney dysfunctions
Dry eyes and mouth
Pathophysiology of myasthenia gravis
Antibodies or destruction of post-synaptic Ach receptors —> weakness, easy fatiguability
Ptosis, dysarthria, dysphagia, resp insufficiency, aspiration
Tx = anticholinesterase (pyridostigmine)
Should you use sux with myasthenia gravis?
Can use Sux when indicated
Typically RESISTANT to sux
If on anticholinesaterase therapy, duration may be prolonged (dec plasma cholinesterase activity)
Not on therapy/undiagnosed –> profound sensitivity of ND-NMBDs
MG patient - After getting neostigmine, resp effort improves but 45 min later complains of weakness and dyspnea. What is the cause?
Myasthenic crisis vs. cholinergic crisis
Give 10mg edrophonium —> improved strength, mydriasis = myasthenic
What is Carcinoid syndrome and why doesn’t it manifest with all carcinoid tumors?
Complex of signs and symptoms that result when vasoactive substances are released from carcinoid tumors –> flushing, bronchoconstriction, diarrhea, right sided heart disease
Most are GI –> portal circulation and removed by liver. Syndrome develops when bypass portal system (mets to liver or outside GI tract
How would you optimize a patient with carcinoid for surgery? Induce?
Diarrhea –> fluid resuscitation
Ocreotide –> dec release of vasoactive substances
Anxiolytic –> dec stress-induced release
H1, H2, steroids –> dec systemic effects of substances
Slow controlled, deep induction to avoid tumor release of vasoactive substances
What are the signs and symptoms of thyrotoxicosis?
Tachycardia Inc CO Dec SVR, PVR Anxiety, agitation, tremors Weakness, sweating, heat intolerance, weight loss Dec TSH, Inc free T3, T4
Cholinergic crisis vs. Anticholinergic crisis
Cholinergic
- DUMBELS
- Organophosphates
- Tx = 2-4mg Atropine, pralidoxime
Anticholinergic
- Hot, Blind, Mad, Dry
- Atropine
- Tx = Physostigmine
Atropine dose
Adults
- 0.5 - 1mg q2-3min
- Max 3mg
Peds
- 0.02mg/kg
- Min 0.1mg –> max 0.5mg
- Max 3mg total
Flumazenil dose
0.2 q 15s
1mg q2min
Max 5mg
How would you assess if a myasthenia patient is optimized for surgery?
I would asses for severity of her symptoms
- ocular only –> respiratory, laryngeal muscles by talking , swallowing
Any issues with previous anesthetics, prolonged intubations
Any episodes of myasthenia crisis
Stability of symptoms over past year
Assess B/L motor strength in extremities and look for pharyngeal muscle involvement
How would you induce a MG patient? Would you use NMBs? If so, which ones? How would you dose? Would you use a twitch monitor?
Assuming a reassuring airway I would
- apply monitors
- Pre O2
- slow controlled induction with short acting agents - remi, prop, lidocaine
I would avoid NMBs if possible because they are highly sensitive to ND-NMBDs. I would use very small dose and titrate or SUX 1.5-2mg/kg due to resistance to sux
I would use a twitch monitor recognizing that may not be reliable. Weakness is uneven and may exhibit fade baseline
What is myasthenic crisis and what are the precipitating factors?
Severe bulbar or respiratory symptoms from progression of disease or other factors.
- infection
- surgery
- stress
- hypothermia
- acidosis
- hypoK
- hypoMag
- aminoglycosides
- flouroquinlones
- clindamycin
- BBs
- CCBs
- NMBDs
- Anticholinergics
Post-op from Pheo resection patients BG is 35. What would you do?
Recheck quickly to confirm
Start D5 infusion
Verify hemodynamically and neurologically stable
Surge of insulin sensitivity following low serum catecholamine levels
How would you address hypothyroidism pre-operatively?
Ideally delay until euthyroid
Inc aspiration risk Inc sensitivity to opioids Hypoglycemia Hypotension Adrenal insufficiency Delayed emergence
MG patient with fever pre-op, is this a concern? Would you give anti-pyretics?
Yes, this could be indicative of a myasthenia crisis or an infection like PNA or C.diff (common in MG).
Therefore I would order blood, sputum or stool cultures based on any other symptoms or perform a Tension test to rule out myasthenia crisis.
I would give anti-pyretics because fever can induce a MG crisis. I would verify any antibiotics are not know to cause MG crisis before administering.
