Which of the following adjunct medications will MOST likely increase seizure duration when used during electroconvulsive therapy?

  • (A) Lidocaine
  • (B) Dexmedetomidine
  • (C) Caffeine
Electroconvulsive therapy (ECT) for depression is considered effective if a seizure lasts 15 to 25 seconds after delivery of the shock. Anesthetic management for ECT usually consists of an intravenous injection of a hypnotic drug followed by a paralytic drug. The hypnotic agent is administered to ensure amnesia prior to pharmacological paralysis and ECT. The paralytic medication (often succinylcholine or rocuronium) prevents injury to the patient during ECT and the resulting seizure. The seizure is observed and measured using two methods. Direct recording of the electroencephalogram is done with electrodes positioned on the head. Observation of the motor seizure is accomplished by isolating a limb (usually the foot) from the effects of the paralytic drug using a proximal tourniquet. The time of tonic-clonic contractions of the foot is then measured.

Methohexital and propofol are commonly used hypnotic agents that also have some anticonvulsant effect. Propofol’s anticonvulsant properties lead to a shorter seizure duration. The addition of intravenous lidocaine prior to the injection of propofol, ostensibly to prevent propofol-induced pain on injection, may further decrease seizure duration.

Other adjunctive medications have been investigated that reduce the amount of hypnotic medication needed to ensure amnesia. For instance, dexmedetomidine added to a hypnotic has no direct effect on seizure duration but may reduce increases in blood pressure and heart rate that occur as a result of ECT.

Adjuncts, including glycopyrrolate, labetalol, and esmolol, are used to treat the parasympathetic and sympathetic responses to ECT. Ondansetron may be administered to prevent nausea, and nonsteroidal anti-inflammatory agents are often given to help with muscle pain. Caffeine has been shown to enhance seizure quality and duration when used as an adjunct to ECT.

Answer: C