Unilateral nondominant electrode placement as a risk factor for recall of awareness under anesthesia during electroconvulsive therapy.

BACKGROUND: Awareness under anesthesia can be a frightening experience for patients receiving electroconvulsive therapy (ECT). CASE REPORT: We present a 19-year-old, 62-kg, bipolar woman who was prescribed right unilateral ECT for a treatment-refractory major depressive episode. Her premedication comprised thiopentone sodium (200 mg) and succinylcholine (30 mg). She received 3 treatments uneventfully. A day after the fourth treatment, she described her awareness of paralysis during the last procedure and refused further treatment despite the marked improvement that had resulted with ECT. DISCUSSION: Electroconvulsive therapy is more usually administered with bilateral than with unilateral electrode placement. During ECT, awareness under anesthesia and recall of paralysis (resulting from inadequate doses of anesthesia and/or premature administration of the muscle relaxant) may be more common than is generally realized but may not be reported by patients because bilateral ECT tends to obliterate the memory of the ECT procedure. If this is true, unilateral nondominant ECT, which is relatively memory sparing, may increase the chance of recollection of paralysis when narcosis under anesthesia is incomplete. Careful clinical assessment and monitoring of the depth of anesthesia using the bispectral index can minimize this risk of awareness under anesthesia.