In general, medications that would interfere with the seizure (anticonvulsants and benzodiazepines) should be minimized, and medications that optimize the patient’s medical condition (most importantly antihypertensives and antireflux medi-cations) should be given before the treatment.1,5 There has been a recent revival of interest in concomitant use of antidepressant medications and ECT: the goal is improved antidepressant efficacy and protection against relapse when the course of ECT is completed.6 Certain medications, including MAO inhibitor antidepressants, lithium(Drug information on lithium), and theophylline(Drug information on theophylline), present specific issues that may require modifications in ECT, anesthesia technique, or patient instructions.7-9 The full range of concomitant medication issues is covered elsewhere.1,10,11
The 2 most commonly used anesthetic agents for ECT in the United States are methohexital(Drug information on methohexital) and propofol(Drug information on propofol). Less commonly used anesthetics are thiopental sodium(Drug information on thiopental sodium), etomidate(Drug information on etomidate), and ketamine(Drug information on ketamine). An optimal anesthetic for ECT should put the patient to sleep quickly but for a short time and not interfere too much with the induction of the ECT seizure.
Methohexital is an ultrashort-acting barbiturate that has become the anesthetic of choice in ECT practice. It renders the patient unconscious quickly (in about 45 seconds) and lasts just long enough for the ECT procedure. Because it is a barbiturate, it has some anticonvulsant properties, but not enough to interfere with ECT. It is easy to dose, administered as an intravenous bolus of about 1 mg/kg of patient weight. It is quite inexpensive and is available as a generic.
Propofol is probably the second most commonly used anesthetic for ECT. It is a milky white liquid that is also given by intravenous bolus. Advantages over methohexital include a “smoother wake up” and a somewhat more favorable hemodynamic profile. Disadvantages are its much greater anticonvulsant effect and higher cost.
Etomidate is an alternative agent that has less anticonvulsant effect than methohexital. It is sometimes used when seizures are short or hard to elicit.
Ketamine is a very interesting agent that is slightly proconvulsant and has intrinsic antidepressant properties. Disadvantages include hypertension and occasional transient dissociative symptoms on wake up. If its antidepressant qualities prove to be additive with ECT, its use could increase.12-14
Muscle relaxation to eliminate the motor component of the ECT-induced seizure has been a feature of ECT since the 1950s. Muscle relaxation during the application of the stimulus, as well as for the duration of the motor portion of the seizure, prevents musculoskeletal injury. Because of the short duration of ECT, succinylcholine is the drug of choice for neuromuscular blockade, although for patients in whom its use is contraindicated, rocuronium or other nondepolarizing agents are alternatives.15 Succinylcholine is a depolarizing neuromuscular blocker with an ultrashort duration of action, slightly less than that of the anesthetic agent. The duration of muscle paralysis is thus very brief, and spontaneous respirations return shortly after the seizure ends.