Impact of Sevoflurane and Thiopental Used Over the Course of Electroconvulsive Therapy: Propensity Score Matching Analysis

Objective

Although anesthetics play an important role in electroconvulsive therapy (ECT), the clinical efficacy and seizure adequacy of sevoflurane in the course of ECT remain unclear. The purpose of this study was to examine the clinical efficacy and seizure adequacy of sevoflurane, compared with those of thiopental, in the course of ECT in patients with mood disorders.

Methods

We conducted a retrospective chart review. Patients who underwent a course of ECT and received sevoflurane (n = 26) or thiopental (n = 26) were included. Factors associated with ECT and treatment outcomes were compared between the two groups using propensity score (PS) matching. Between-group differences were examined using an independent t-test for continuous variables and a χ²-test for categorical variables.

Results

Patients who received sevoflurane needed more stimulations (sevoflurane: 13.2 ± 4 times, thiopental: 10.0 ± 2.5 times, df = 51, p = 0.001) and sessions (sevoflurane: 10.0 ± 2.1 times, thiopental: 8.4 ± 2.1 times, df = 51, p = 0.01) and had more inadequate seizures (sevoflurane: 5 ± 3.9 times, thiopental: 2.7 ± 2.7 times, df = 51, p = 0.015). Remission and response rates were similar in both groups.

Conclusion

The present findings indicate that sevoflurane should be used with caution in ECT and only when the clinical rationale is clear.

Sevoflurane in electroconvulsive therapy: A systematic review and meta-analysis of randomised trials

Sevoflurane is the most commonly used inhaled anaesthetic in electroconvulsive therapy (ECT). The objective of this study was to provide an up-to-date and comprehensive review on how the use of sevoflurane affects seizure adequacy (seizure duration and postictal suppression index [PSI]) and circulatory dynamics in ECT. We performed a meta-analysis of RCTs that investigated seizure adequacy and circulatory dynamics in patients treated with ECT using sevoflurane (sevoflurane group) and intravenous anaesthetics (non-sevoflurane group). A total of 12 RCTs (377 patients and 1339 ECT sessions) were included. Sevoflurane significantly decreased the electroencephalogram (EEG) seizure durations in comparison with intravenous anaesthetics, whereas no significant difference was observed in PSI (EEG: 9 studies, standardized mean difference (SMD) = 0.74, 95% confidence interval (CI) = -1.11 to -0.38, p = 0.0002; PSI: 4 studies, SMD = -0.06, CI -0.13 to 0.25, p = 0.59). The use of sevoflurane in ECT significantly increased heart rate (HR) compared with intravenous anaesthetics (9 studies, SMD = 0.31, CI 012-0.51, p = 0.004). In the pre-planned subgroup analysis, sevoflurane significantly reduced seizure duration compared with other types of anaesthetics, including propofol, barbiturates and ketamine. Furthermore, it was found that the risk of adverse events in ECT with sevoflurane were not significantly different from intravenous anaesthetics (6 studies, risk ratio = 1.33, CI 0.95-1.86, p = 0.09), with agitaion being the most common adverse effects. The results of our study suggest that using sevoflurane for ECT significantly reduces seizure duration, increases maximum HR and brings about no difference in the adverse event risk compared with those using intravenous anaesthetics for ECT. Therefore, there may not be compelling evidence favouring sevoflurane use for ECT, except in cases where intravenous access is difficult.

Remifentanil as an adjunct to anaesthesia for electroconvulsive therapy fails to confer long-term benefits

BACKGROUND

Adding the μ-opioid receptor agonist remifentanil to agents used to induce general anaesthesia in electroconvulsive therapy (ECT) can reduce the required doses of induction agents and their unfavourable effects on seizure threshold and quality. However, whether remifentanil has favourable long-term treatment effects in terms of response and remission rates, speed of response and remission, and side-effects has not been studied.

METHODS

This retrospective, register-based cohort study involved patients with major depression consecutively treated at two units at different hospitals in Norway with the same ECT procedure. Both units used thiopental for ECT anaesthesia, but only one unit added remifentanil (R+; n=47; 541 sessions), whereas the other did not (R-; n=119; 1166 sessions). A Cox proportional hazards model for interval-censored data was conducted to examine the effects of remifentanil on the time to response and remission from depressive symptoms, whilst adjusting for age, sex, and baseline depression score.

RESULTS

Both R+ and R- patients showed substantial reductions of depressive symptoms, with no difference in the response (76% in both groups) or remission (63% vs 65%) rate. However, R+ patients responded (hazard ratio=0.59; 95% confidence interval: 0.4-0.8) and remitted (hazard ratio=0.72; 95% confidence interval: 0.5-1.0) more slowly, and reported more often side-effects of nausea (30% vs 8%; P<0.001), dizziness (22% vs 8%; P=0.027), and headache (48% vs 23%; P=0.004).

CONCLUSIONS

The use of adjunctive remifentanil was associated with more short-term side-effects and no favourable long-term clinical outcomes. The practice of routinely adding remifentanil to barbiturate anaesthesia should therefore be reconsidered.

Remifentanil in electroconvulsive therapy: a systematic review and meta-analysis of randomized controlled trials

In electroconvulsive therapy (ECT), remifentanil is often used concurrently with anesthetics. The objective of this study was to provide an up-to-date and comprehensive review on how the addition of remifentanil to anesthetics affects seizure duration and circulatory dynamics in mECT. We performed a meta-analysis of RCTs that investigated seizure duration and circulatory dynamics in patients treated with ECT using anesthetics alone (non-remifentanil group) and with anesthetics plus remifentanil (remifentanil group). A total of 13 RCTs (380 patients and 1024 ECT sessions) were included. The remifentanil group showed a significantly prolonged seizure duration during ECT compared to the non-remifentanil group [motor: 9 studies, SMD = 1.25, 95 % CI (0.21, 2.29), p = 0.02; electroencephalogram: 8 studies, SMD = 0.98, 95 % CI (0.14, 1.82), p = 0.02]. The maximum systolic blood pressure (SBP) was significantly reduced in the remifentanil group compared to the non-remifentanil group [7 studies, SMD = -0.36, 95 % CI (-0.65, 0.07), p = 0.02]. Substantial heterogeneity was observed for meta-analyses for seizure durations, but a pre-planned subgroup analysis revealed that seizure duration was prolonged only when the use of the anesthetic dose was reduced in the remifentanil group. The results of our study suggest that addition of remifentanil to anesthesia in ECT may lead to prolonged seizure duration when it allows the use of reduced anesthetic doses. Further, the addition of remifentanil was associated with reduced maximum SBP.