Factors Associated With Seizure Adequacy Along the Course of Electroconvulsive Therapy

Does Lidocaine Shorten Seizure Duration in Electroconvulsive Therapy?

BACKGROUND

Electroconvulsive therapy (ECT) is an effective short-term treatment for schizophrenia and depression, amongst other disorders. Lidocaine is typically added to reduce pain from intravenous propofol injection. However, depending on the dose used in the ECT setting, it can shorten seizure duration. The aim of this study was to investigate the effect of lidocaine dose on seizure duration.

METHODS

This retrospective, naturalistic cohort study included 169 patients treated with ECT. We examined 4714 ECT sessions with propofol or propofol plus lidocaine. Ictal quality was manually rated by visual inspection. The main outcome of this study was the relation of lidocaine with seizure duration after controlling for socio-demographic, ECT, and other anesthetic variables.

RESULTS

There was a significant negative association between lidocaine usage and seizure duration. Multivariate analyses showed that seizure duration was shortened by an average of 3.21 s in sessions with lidocaine. Moreover, in this subgroup, there was a significant negative dose-dependent association between lidocaine dose and seizure length. Complementarily, a significant positive association between preictal BIS and seizure length was found in the subgroup of sessions where preictal was used.

CONCLUSIONS

We provide additional evidence highlighting the importance of caution regarding lidocaine dosing due to the effect on seizure length in the ECT setting. It is advisable for clinicians to exercise caution when administering lidocaine regarding its dosing and seizure length in ECT settings. Future investigation is needed to assess causal relationships by studying certain vulnerable groups or employing other charge calculation techniques, such as the titration method.

Relationship Between Anesthesia Depth and Quality of Seizures in Patients Undergoing Electroconvulsive Therapy: A Prospective Observational Study

OBJECTIVES

Electroconvulsive therapy under general anesthesia is an established treatment for mood disorders, such as therapy-resistant depression. As most anesthetic drugs used for induction of anesthesia increase the seizure threshold, adequate depth of anesthesia without diminishing the therapeutic efficacy of interventions is crucial. The aim of this study was to investigate whether anesthesia depth as assessed by Narcotrend (NCT) monitoring correlates with maximum seizure quality.

METHODS

An observational study was performed in psychiatric patients undergoing multiple interventions of electroconvulsive therapy. Seizure quality of each attendance was assessed evaluating electroencephalogram end point, electromyogram end point, postictal suppression index, the midictal amplitude, and a 3-step overall graduation. Narcotrend was used to assess anesthesia depth according to index-based electroencephalogram findings. Measurements were obtained before induction of anesthesia, before stimulation, and after arousal. Data were analyzed by means of linear mixed models and generalized estimating equations models.

RESULTS

A total of 105 interventions in 12 patients were analyzed. Anesthesia depth before stimulation was significantly associated with seizure quality (standardized β = 0.244, P = 0.010), maximum sustained coherence (β = 0.207, P = 0.022), and electroencephalogram duration (β = 0.215, P = 0.012). A cutoff value of 41 or greater versus 40 or less for the NCT index was found appropriate to differentiate between good and less satisfactory overall seizure quality.

CONCLUSIONS

Anesthesia depth index assessed by NCT monitoring was positively associated with seizure quality. Narcotrend monitoring may be useful in assessment of optimal anesthesia depth before stimulation.

Changes in seizure duration during acute course electroconvulsive therapy

BACKGROUND

Seizure duration has long been measured as a potential marker of ECT treatment efficacy, with concern that short seizures may be clinically ineffective. Relatively small studies have documented a trend towards shorter seizures during acute course ECT, but data from large cohorts would help provide normative data on seizure duration changes during treatment.

OBJECTIVE

This study analyzes the effects of age, sex, ECT dose, and treatment number on the duration of electrographic seizures during acute course ECT in a large single-center cohort.

METHODS

A single-center retrospective chart review was conducted of adult patients receiving a first course of ECT from 2000 to 2017 at a large freestanding psychiatric hospital.

RESULTS

3648 patients met inclusion criteria, receiving 32,879 acute course ECT treatments. There was a shortening of mean ECT seizure duration over the acute course, with the greatest decrease in duration over the first 3 treatments but continuing decreases over the entire acute course. Older age, higher ECT dose, and increasing treatment number were all associated with shorter seizures, while sex was not significantly associated. Increasing treatment dose was associated with shorter seizures relative to no dose increase, with those patients receiving the highest cumulative doses also having the shortest cumulative seizure time.

CONCLUSIONS

Among patients undergoing acute-course ECT treatment, seizure duration decreased over the treatment course, and increases in applied electrical charge were associated with shorter seizures.