What medications are used for induction of anesthesia for Electroconvulsive Therapy (ECT)?

Medications Used for Induction of Anesthesia for ECT

Methohexital at 1.0 mg/kg IV is the preferred anesthetic agent for ECT induction, with acceptable alternatives including etomidate, thiopental sodium, ketamine, and propofol. 1, 2

Primary Anesthetic Agents

First-Line Agent

• Methohexital is the most commonly used and recommended anesthetic agent at a standard dose of 0.75-1.0 mg/kg IV 1, 2, 3
• This barbiturate provides rapid induction with appropriate seizure characteristics and recovery profiles 3

Alternative Anesthetic Agents

When methohexital is contraindicated or unavailable, the following alternatives are acceptable:

• Etomidate: Produces longer seizure durations than methohexital (24% longer mean wakeup time), with comparable hemodynamics but higher incidence of injection pain 2, 4
• Thiopental sodium: Acceptable barbiturate alternative 1
• Ketamine: Produces the longest seizures and may have proconvulsant properties 2, 5
• Propofol: Results in the shortest seizure durations and may require higher stimulus dosing, more bilateral treatments, and more total ECT sessions, particularly with unilateral electrode placement 5, 6

Important caveat: Propofol should be used cautiously as it is associated with significantly shorter seizures, higher restimulation rates for brief seizures, and increased need for bilateral ECT compared to methohexital 6

Muscle Relaxants

• Succinylcholine at 0.5-1.0 mg/kg IV is the standard muscle relaxant 1, 2, 3
• Atracurium and mivacurium are acceptable alternatives 1, 2

Anticholinergic Medications

• Atropine (IV) or glycopyrrolate should be administered immediately before ECT to prevent bradycardia, arrhythmia, or cardiac asystole 1, 2
• These agents are required before seizure threshold determination by dose titration and before the first treatment with right unilateral electrode placement to protect against vagal discharge 1, 2

Adjunctive Agents for Hemodynamic Control

For patients at risk from tachycardia and hypertension during ECT:

• Nitroglycerin, propranolol, hydralazine, or other sympatholytic agents should be used to attenuate cardiovascular responses 3
• Remifentanil (500 mcg IV bolus) combined with low-dose methohexital (40 mg IV) significantly reduces heart rate and blood pressure responses throughout the procedure 7

Ventilation Protocol

• 100% oxygen must be administered via ventilation before electrical stimulus delivery 1, 2
• Manual hyperventilation with 100% oxygen may improve seizure quality by optimizing the pO2/pCO2 ratio 5

Special Considerations for Combination Therapy

• Ketamine + propofol (1:1 ratio) may yield seizures with the best quality characteristics 5
• This combination balances propofol's anticonvulsant properties with ketamine's proconvulsant effects 5

Agents for Terminating Prolonged Seizures

If seizures exceed 180 seconds (occurring in 0-10% of treatments):

• Additional methohexital, diazepam, or lorazepam can effectively terminate prolonged seizures 2, 8