Case 17 - ECT Flashcards
what are anesthetic considerations during ECT?
1) safe anesthetic without suppresing the therapeutic seizure
2) manage physiologic effects of tx (symp and parasymp response)
3) manage transient effects of anesthetic (ie airway management)
are there any relative or absolute contraindications to ECT? Suppose you have a severe CAD or recent MI patient undergoing urgent ECT for life-threatneing psychiatric illness?
ECT
- iniitally associated with brief parasymp response -> bradycardia, asystole
- after seizure, associated with extreme sympathetic response -> HTN, Tachy
relative contraindications
- increased ICP (may be exacerabed during tx)
- recent hemorrhagic stroke (< 1 month)
- retinal detachment
- severe CAD (symp surge can cause MI)
CAD or recent MI pts undergoing emergent ECT
- *with CAD or recent MI -> asses risk vs benefit. *
- risk of MI vs benefit of tx a life-threatening suicidal patient. if proceed with ECT, then administer BB and manitain BP and HR with short acting BB and vasodilators (NTG)
how will you manage a pt undergoing ECT who has an ICD?
ICD
- ECT can generate artifacts, which the ICD will sense as a treatable rhythm -> shock the patient
- worst case scenario = inappropraite shock during repolarizatoin = R on T phenomenon -> VFIB
- you can either leave on or turn off
- ON - reason -> even if patient goes into ventric arrhythmia for any reason, ICD is best tx (immediate response, available, no pads palced)
- OFF - avoid R on T. place magnet on ICD to turn off
how will you manage a pt undergoing ECT who has a PPM?
PPM
- learn why it was placed, current settings, underlying rhythm, magnet response
- have external pacing equip readily available
- ECT can cause artifactial interference of PPM resulting in inhibition of PPM output
- Place magnet into asynch mode (not affected by intereference)
what are physiologic effects of ECT?
parasymp response followed by intense symp response
1) parasymp response
- initial ECT dischrage
- bradycardia, asystole
- consider pre-tx with glyco
2) symp surge
* after stimulus termination, intense symp surge -> HTN and tachy
what is an approrpiate anesthetic for ECT? what are your goals for anesthesia during ECT?
Goals:
- rapid onset and rapid termination of anesthetic
- do not increase seizure threshold
- fast acting muscle relaxant
- maintain airway throughout procedure
- ECT is a short procedure
1) IV induction agents
- methohexital = agent of choice
- fast onset, fast emergence, reliable
- does not increase seizure threshold
- sux = agent of choice
- fast onset, fast emergence, reliable
- muscle relax used to prevent patient injury during motor sizures
if no methohexital, use etomidate.
propfol is anticonvulsant and increases seizure thereshold
what are two ways you can get pulmonary edema after ECT?
1) Negative pressure pulm edema
- inspiratoin against a closed glottis
- lax pharyngeal muscles are unable to lift soft tissue out of the way -> upper airway collapse and obstruction
- strong neg inspiratory pressure against an obstruction -> transudation of fluid into alveoli and interstital space
2) neurogenic pulm edema
* intense symp surge after ECT stimulus -> increase LV afterload and myocardial ischemia -> acute L CHF -> flash pulm edema
Tx for both:
- airway support (o2, intubation)
- diuretics
- control elevated BP (neuorgenic cause)
patient undergoes ECT with methohexital and sux. After procedure, you are masking the patient for 15 minutes, and you see no return of spont ventilatoin. You are suspecting a psuedocholinesterase dysfunction. what can be causes?
pseudocholinesterase dysfunctoin
1) genetic
- heterozygous pseudo deficiency - 70 to 120 min
- homozygous psuedo deficiency - up to 8 hours
2) acquired (lasts 10-25 minutes)
- liver disease (decrease synthesis)
- pregnancy (hemodilution)
- echothiophate eye drops (inhibits psuedo enzyme)
- pyridostigmine (MG patients, cholinesterase inhib)
- chemotherapy (cyclophosphasmide -> inhibits activity)
