Electroconvulsive TherapyElectroconvulsive Therapy

Presented by 許仲寬 91-09-17

Current condition in Current condition in 西址 西址 OROR

Monitor setup, EEG Preoxygenation, bite protection Rapifen 1ml, Pentothal 150mg~250mg One lower leg isolated with tourniquet Succinylcholine 60~80mg ECT discharge Recovering (Trandate if necessary) Recheck v/s, pupil reflex

ECTECT

Programmed electrical stimulation of the CNS to initiate seizure activity. The precise mechanism remains unknown.

The electrical stimulus results in generalized tonic activity for approximately 10 seconds, followed by generalized clonic activity for a variable period ranging from a few seconds to more than 1 minute.

Overall seizure duration is a primary determinant of treatment efficacy

25~50s optimal, <15s, >120s ineffectiveDuration depends on age, energy of

stimulus delivered, electrode placement, seizure threshold, and medications administered, including anesthetics.

Electrodes may be placed bilaterally or unilaterally. Bilateral is more effective, but results in greater cognitive side effects

Indication of ECTIndication of ECT

severe and medication-resistant depression and mania

schizophrenic patients with affective disorders, suicidal drive, delusional symptoms, vegetative dysregulation, inanition, and catatonic symptoms

75~85% favorable response

Mortality: 1 per 10,000 (1997, APAC) Cause – cardiovascular decompensation,

prolonged apnea, status epilepticus, cerebral herniation

Morbidity: cardiovascular complication, bone fractures, musculoskeletal injuries, oral injuries

Side effect: headache, muscle pain, nausea Cognitive dysfunction: amnesia, Postictal

Delirium

PhysiologyPhysiology Initial parasympathetic discharge,10~15s,

manifested by bradycardia, occasional asystole, and/or premature atrial and ventricular contractions. Hypotension and salivation may be noted.

Followed by sympathetic discharge, associated with tachycardia, hypertension, premature ventricular contractions, and rarely ventricular tachycardia. The tachycardia peaks at 2 minutes after stimulus and is normally self-limited.

ECG changes including ST-segment depression and T-wave inversion may also be seen, without myocardial enzyme changes consistent with myocardial infarction.

SBP is transiently increased by 30%–40%, and HR is increased by 20% or more, resulting in a two- to fourfold increase in the rate-pressure product (RPP), an index of myocardial oxygen consumption

Increases in cerebrovascular resistance followed immediately by increased cerebral blood flow and cerebral metabolic rate

Hyperventilation-induced hypocapnia appears to augment the HR and RPP responses compared with normocapnic conditions

DRUGSDRUGS

Methohexital: gold standard 0.75-1 mg/kg Thiopental 1.5-2.5mg/kg: shorten duration,

increase bradycardia & PVC, higher MCA flow velocity than propofol

Etomidate 0.15-0.3 mg/kg: longer duration, accentuate hemodynamic response

Propofol 0.75 mg/kg: potent anticonvulsant, cardiovascular depressant, in larger dose 1.5mg/kg, duration shortened but improvement not affected

Ketamine: intrinsic sympathomimetic activity, shortened duration

Benzodiazepine: avoided, anticonvulsantSevoflurane: 1.7% Sev + 50% nitrous

oxide, or 3.4% Sev alone, similar to thiopental, for late stages of pregnancy to reduce uterine contraction

Succinylcholine: 0.5, 0.75-1.5 mg/kg, avoided in malignant hyperthermia, neuroleptic malignant syndrome

Mivacurium 0.2mg/kg: most often alternative

Atracurium 0.5mg/kg: onset 6 min, recovery 16min

Rocuronium: no clinical reports

Glycopyrrolate: drug of choice, reduce oral secretion and bradycardia

Esmolol 1-1.3 mg/kg Labetalol 0.1-0.2 mg/kg Sublingual nifedipine 10mg, 20 min before NTG 3ug/kg 2 min before Nitroprusside + b-blocker: for intracranial

aneurysm, dissecting aortic aneurysm, aortic stenosis

Opioid: Alfentanil 10ug/kg prolong Fentamyl 1.5ug/kg shorten

Suggested TechniqueSuggested Technique

NPO overnight, clear fluid allowed 1 h before To prevent myalgias, aspirin, acetaminophen,

ketorolac given as premedication Oral airway required for both ventilation and

protection EEG, EMG, tourniquet technique to isolate an

extremity for seizure activity quantification

Special conditionSpecial condition

Cerebral aneurysm- propofol, atenolol 50mg, nitroprusside 30ug Subdural hemorrhage, intracranial mass- unilateral electrode away from the lesion- pretreat with steroid, diuretic, hyperventilation Cardiovascular disease- B-blocker for CAD- Anticoagulation for AF- Atropine & avoid large dose SCC for bradycardia- Pheochromocytoma should be excluded

NMS

- Avoid succinylcholine & sevoflurane Pregnancy

- tocolytic, sevoflurane, rapid sequence induction Inadequate seizure activity

- etomidate, reduced methohexital in combination with alfentanil / remifentanil, aminophylline, caffeine

ReferencesReferences

Anesthesia for electroconvulsive therapy (Anesth Analg 2002;94:1351-64)

Treatment of Psychiatric Disorders (Glen O. Gabbard, p1267-1293)

Anesthesia (Miller, Ch.70 p2269-2273) Clinical Anesthesiology (Morgan, Ch 27, p594-

596) Clinical Anesthesia Procedures of MGH (Hurford,

Ch 31, p558-561)