Effects of the concurrent use of a reduced dose of propofol with divided supplemental remifentanil and moderate hyperventilation on duration and morphology of electroconvulsive therapy-induced electroencephalographic seizure activity: A randomized controlled trial

Study objective: The clinical adequacy of electroconvulsive therapy (ECT) depends on not only seizure duration but also seizure amplitude and postictal suppression. The objective of this study was to evaluate the effects of combination of a reduced dose of propofol and moderate hyperventilation on seizure duration and electrical stimulus requirement for adequate ictal amplitude and postictal suppression. Design: Prospective, randomized, controlled trial. Setting: Operating room at a municipal hospital. Patients: Sixty ASA physical status I or II patients scheduled to receive a total of >300 Ea treatments. Interventions: Patients were randomly assigned to have the three interventions: the use of a standard dose (1 mg/kg) of propofol and normoventilation (ETCO2 of 40-45 mm Hg) (group P/N), the use of a reduced dose (0.5 mg/kg) of propofol with divided remifentanil injections and normoventilation (group RP/N), and the use of a reduced dose of propofol with divided remifentanil injections and moderate hyperventilation (ETCO2 of 30-35 mm Hg) (group RP/H). Patients in groups RP/N and RP/H received remifentanil 1 pg/kg followed by propofol 0.5 mg/kg for unconsciousness and thereafter remifentanil 1 mu g/kg immediately before the electrical stimulus. Measurements and main results: Patients in group RP/H had significantly longer durations of electroencephalographic (EEG) seizures in the early phase of the ECT course (P < 0.05) and lower intensities of electrical stimulus in the late phase of the Ea course (P < 0.05) than those in groups P/N and RP/N. Conclusion: A reduced dose of propofol combined with divided supplemental remifentanil under moderate hyperventilation during ECF may contribute to reduced electrical dosage due to the ability of its augmentation of seizure amplitude and postictal suppression in the late phase of the Ea course. (C) 2016 Elsevier Inc. All rights reserved.