Strabismus Changes

Question 1

Premeds for strabismus surgery

Answer 1

consider atropine (20mcg/kg) or glyco (10-20mcg/kg) to decrease secretions and airway hyperresponsiveness (reduced vagal tone) and to anticipate bradycardia events associated with the oculocardiac reflex

• increased aspiration risk 2/2 oculogastric reflex - ondansetron, dexamethasone, ketorolac (decrease opiates), fluid bolus, oral Midaz

Question 2

When to delay a peds case

Answer 2

Increased risk of laryngospasm, bronchospasm, oxygen desaturation

Elective case with 2/2 of URI (fever
4-6 weeks: tempt >38.5, productive cough, muculopurulent secretions, malaise)
2-4 weeks (mild - sneezing, congestion, nonproductive cough)
proceed: not requiring GETA, can use LMA or regional
increased risk: RAD, exposure to smoking, require GETA

Question 3

why don’t we like succs in kids <8 (ESP. males)

Answer 3

unmasked muscular dystrophies (hyperkalemia, rhabdo -> cardiac arrest)

increased exntrajunctional acetylcholine receptors

Question 4

you gave succs but can’t open jaw - why?

Answer 4

IV working, adequate dose
* succs induced masseter muscle rigidity (risk of developing MH is 30-50% after severe MMR reaction)
* undiagnosed myotonic syndrome
* undiagnosed muscular dystrophy
* malignant hyperthermia

Question 5

what can rhabdo cause

Answer 5

hyperkalemia dysrhythmias, ATN, myalgias, peripheral compartment syndrome, obstructive nephropathy

Question 6

what are we monitoring for in suspect MH case

Answer 6

myoglobinuria, electrolyte disturbances, hyper metabolic processes, generalized rigidity, CK >20,000

Question 7

criteria for caffeine halothane contracture test

Answer 7

at least 7 years old
20 kg

Question 8

how to prepare anesthesia machine for MH

Answer 8

• remove all triggering agents
• new circuit/co2 absorbent
• filters
• flush 10L for at least 10 min
• ensure MH cart with dantrolene, cooling agents nearby

Question 9

bradycardia during surgery

Answer 9

• ask surgeon to stop
• ensure proper oxygenation (check vent, tube, ausculate lungs)
• worsened with light anesthesia or deep (cardiac depressant)
• worsened with hypoxemia or hypercarbia so fix these
• atropine 0.02mg/kg
• last resort - have surgeon inject rectus muscle with local anesthetic

Question 10

what is oculocardiac reflex

Answer 10

occurs most commonly with medial rectus but can be any orbital muscle
* afferent 5 (ciliary of ophthalmic of trigeminal)
* e (exit)fferent 10 (vagus)
*subject to fatigue so if treated, less likely to recur

Question 11

MH symptoms

Answer 11

tachycardia, rigidity, hyperthermia, hypotension, arrhythmias, sweating, cyanosis, peripheral mottling

Question 12

how to assess for MH clinically

Answer 12

ABG - PaO2 and looking for mixed respiratory and metabolic acidosis
hyperK
hyperCa
elevated CK
myoglobinuria