The comparative effects of sevoflurane and methohexital for electroconvulsive therapy

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.

The Historical Struggles of Modified Electroconvulsive Therapy: How Anesthesia Came to the Rescue

The complicated history of modified electroconvulsive therapy (ECT) started back before anesthesia was incorporated when unmodified electroconvulsive therapy was not considered humane. When anesthesiologists started working with psychiatrists, ECT gradually regained acceptance by decreasing the obstacles inherent to this therapy despite the complexities of the anesthetics. However, the sociopolitical and medicolegal factors negatively impacted the use of modified ECT leading to a period of time when it was banned from use in the United States. Fortunately, as advances in anesthesia and technology continued to develop, anesthesiologists helped ECT regain widespread usage improving the safety profile, cost effectiveness, quicker onset of seizures, and ease of control despite its stained past. This allowed more accessibility, especially for high-risk medical patients, to a relatively safe and effective treatment for psychiatric diseases.

Electroconvulsive Therapy for Depression Comorbid With Myasthenia Gravis: A Case Report and Review of the Literature

OBJECTIVES

Myasthenia gravis (MG) is a rare but well-described autoimmune disease, which is sometimes comorbid with psychiatric illness. There have been several case reports describing the use of electroconvulsive therapy (ECT) for the treatment of core psychopathology in the context of MG. We sought to review the available published data on ECT in MG and add another case example to the literature.

METHODS

We performed a PubMed search for relevant articles or case reports in English describing ECT in MG and summarized findings.

RESULTS

We identified 7 published cases meeting our inclusion criteria in varying detail with different psychiatric presentations and different anesthetic and ECT technique approaches. In addition, we add our own case.

CONCLUSIONS

Based on the literature and our own clinical experience, ECT seems to be a safe option for the treatment of core psychopathology with comorbid MG as long as appropriate precautions are in place, particularly when choosing an anesthetic approach.

Anesthetic considerations for pediatric electroconvulsive therapy

Electroconvulsive therapy is being used more frequently in the treatment of many chronic and acute psychiatric illnesses in children. The most common psychiatric indications for pediatric electroconvulsive therapy are refractory depression, bipolar disorder, schizophrenia, catatonia, and autism. In addition, a relatively new indication is the treatment of pediatric refractory status epilepticus. The anesthesiologist may be called upon to assist in the care of this challenging and vulnerable patient population. Unique factors for pediatric electroconvulsive therapy include the potential need for preoperative anxiolytic and inhalational induction of anesthesia, which must be weighed against the detrimental effects of anesthetic agents on the evoked seizure quality required for a successful treatment. Dexmedetomidine is likely the most appropriate preoperative anxiolytic as oral benzodiazepines are relatively contraindicated. Methohexital, though becoming less available at many institutions, remains the gold standard for induction of anesthesia for pediatric electroconvulsive therapy though ketamine, propofol, and sevoflurane are becoming increasingly viable options. Proper planning and communication between the multidisciplinary teams involved in the care of children presenting for electroconvulsive therapy treatments is vital to mitigating risks and achieving the greatest therapeutic benefit.

Sevoflurane versus propofol for electroconvulsive therapy: effects on seizure parameters, anesthesia recovery, and the bispectral index

BACKGROUND/AIM

In this prospective randomized cross-over study we compare the effects of sevoflurane versus propofol for electroconvulsive therapy (ECT) anesthesia.

MATERIALS AND METHODS

Twenty four patients (ASA I-III, 18-65 years old) receiving ECT three times per week were included. Anesthesia was induced with either propofol (0.75 mg/kg iv) or 5% sevoflurane in 100% oxygen. Consecutive ECT sessions followed a 2 × 2 crossover design and a 2-day washout period until the 10th ECT. Intravenous succinylcholine (1 mg/kg) was administered while bispectral index (BIS) values were ≤60%.

RESULTS

Electromyogram and electroencephalogram seizure duration, postictal suppression index, BIS values, mean arterial blood pressure (MAP), heart rate, times to start of spontaneous respiration, eye opening, understanding verbal commands, and side effects were compared. No differences were found between the regimens for seizure activity and recovery. At the end of ECT, MAP was higher with sevoflurane. Although BIS values were higher after sevoflurane, no differences between the regimens were found in terms of the need of muscle relaxants and in hypnosis levels.

CONCLUSION

Sevoflurane (5%) may be an effective alternative to propofol for induction of anesthesia for ECT.

Sevoflurane/remifentanil versus propofol/remifentanil for electroconvulsive therapy: comparison of seizure duration and haemodynamic responses

OBJECTIVE

To compare the anaesthetic and convulsive effects of sevoflurane/remifentanil versus propofol/remifentanil combination in electroconvulsive therapy (ECT).

METHODS

In this prospective, randomized double-blind study, patients diagnosed with treatment-resistant depression were included for ECT. Prior to treatment, 1 µg/kg remifentanil was intravenously administered to all patients, followed by anaesthetic induction with either 0.5 mg/kg propofol or 8% sevoflurane. Following muscular paralysis with succinylcholine and hypnosis, bitemporal ECT was applied. Vital signs, depth of sedation, recovery parameters, motor and electroencephalography (EEG) convulsion activity and postictal suppression index scores were recorded.

RESULTS

A total of 120 sessions of ECT were administered to 12 patients. Heart rate was higher in the sevoflurane group than the propofol group. Compared with the sevoflurane group, bispectral index level was lower in the propofol group during the induction period and higher during the recovery period. Anaesthetic induction and recovery times were lower, and average motor and EEG convulsion activity was longer, in the propofol group than in the sevoflurane group.

CONCLUSION

Propofol/remifentanil is more successful compared with sevoflurane/remifentanil in anaesthesia management during ECT since it provides quick induction and recovery, longer seizure activity and stable haemodynamics.

Comparison of enflurane and propofol in electroconvulsive therapy, a randomized crossover open preliminary study on seizure duration and anaesthetic recovery

BACKGROUND AND OBJECTIVES

Electroconvulsive therapy (ECT) is commonly used for treatment of depression, mania and affective disorders. Anaesthetics for general anaesthesia during ECT should have rapid onset, rapid emerge, not interfere with seizure activity and not shorten seizure duration. The aim of this study is to compare effects of enflurane, a pro-convulsive anaesthetic agent, and propofol on seizure durations, postictal suppression index and recovery times during electroconvulsive therapy.

METHODS

Unpremedicated subjects were divided into two groups according to induction of anaesthesia. Patients were induced for ECT with 5% enflurane in group E and 1.2mg.kg(-1) propofol in group P until loss of consciousness. The durations of electroencephalogram (EEG) and motor seizures, postictal suppression index, time to spontaneous breathing, duration of eye opening, and obeying commands were recorded.

RESULTS

There was no statistically significant difference between the groups regarding motor and EEG seizure times and postictal suppression index on the EEG records. Recovery times (times of starting spontaneous breathing, eye opening, and obeying command) were significantly shorter in group E compared to group P. No nausea or vomiting were observed and no ECG abnormality was noted except transient sinus bradycardia and sinus tachycardia.

CONCLUSIONS

Although sufficient seizure for the treatment was provided during enflurane anaesthesia, any additional benefit was not revealed regarding seizure times or postictal suppression index when compared to propofol anaesthesia. On the other hand, recovery times after enflurane anaesthesia were shorter than propofol anaesthesia. However, there is still a need for further study in different ETCO(2) levels.

Assessment of QT interval and QT dispersion during electroconvulsive therapy using computerized measurements

BACKGROUND

Electroconvulsive therapy (ECT) used in the treatment of severe psychiatric disorders induces stimulation of the autonomic nervous system with initial parasympathetic outflow immediately followed by a sympathetic response. These responses induce an initial bradycardia, arrhythmias, and hypertension. QT dispersion (QTD), defined as maximal QT interval minus minimal QT interval on 12 leads of the surface electrocardiogram, reflects regional heterogeneity of ventricular repolarization. The effects of electrical stimulus due to ECT on QT interval and QTD are of considerable interest.

OBJECTIVE

: This study was designed to investigate the effects of electrical stimulation caused by ECT on RR interval, QT interval, the rate-corrected QT (QTc) interval, QTD, and the rate-corrected QTD (QTcD) under general anesthesia using computerized measurements.

METHODS

Thirty psychiatric patients scheduled for ECT were studied under propofol anesthesia. A 12-lead electrocardiogram was monitored to measure parameters. Muscle paralysis was achieved by administering succinylcholine 1 mg/kg intravenously, and the efficacy of ECT was determined by the tourniquet technique.

RESULTS

The RR interval and QT interval decreased significantly immediately after electrical stimulus, and returned to the baseline level 1 minute after electrical stimulus. In 25 out of 30 patients, the baseline value of QTc interval was higher than the normal limits, and the QTc interval decreased significantly for 2 minutes after electrical stimulus. In 27 out of 30 patients, the baseline values of QTD and QTcD were higher than the normal limits, and the QTD and QTcD increased significantly from immediately after electrical stimulus to 5 minutes after electrical stimulus.

CONCLUSIONS

The QTc interval, QTD, and QTcD, which were associated with increased risks of ventricular arrhythmias, increased significantly before anesthetic induction in patients with major depression. Electrical stimulus during ECT induced further increases of the QTD and QTcD.

Effects of general anesthetic agents in adults receiving electroconvulsive therapy: a systematic review

OBJECTIVES

Our primary objective was to conduct a systematic review to determine the differential effects of general anesthetic agents on electroconvulsive therapy (ECT) induced motor and electroencephalogram seizure duration. Our secondary objective was to determine the differential effects of induction agents on emergence time, recovery time, and the occurrence of adverse cardiac events and drug effects.

MATERIALS AND METHODS

We searched 4 electronic databases for randomized, crossover, and parallel trials. The weighted mean difference was calculated for continuous variables, whereas the risk difference was assessed for dichotomous variables. We combined crossover- and parallel-designed trials using the inverse variance method, and the random-effects model was used throughout.

RESULTS

Forty-one randomized trials involving 14 induction agents were included. The quality of trials was poor. Clinical and statistical heterogeneity were identified throughout. The most commonly studied comparison was methohexital versus propofol, where the mean motor seizure duration with methohexital was longer compared with that of propofol (weighted mean difference, 9.06 seconds; 95% confidence interval, 5.72-12.40). However, combining methohexital or propofol with a short-acting opioid prolonged seizure duration. Small but significant variations in emergence and recovery times were identified. Inadequate data were available to draw conclusions regarding adverse cardiac events and drug effects. No deaths were reported.

CONCLUSIONS

Whereas the relationship between ECT seizure length and efficacy remains unclear, all of the available induction agents in this review would be appropriate for ECT. When the clinician needs to prolong seizure length, methohexital or the addition of a short-acting opioid to methohexital or propofol should be considered. The small variations in emergence and recovery times should not govern the choice of an induction agent.

Cognitive impairment following electroconvulsive therapy--does the choice of anesthetic agent make a difference?

The range of drugs available to provide anesthesia for patients undergoing electroconvulsive therapy (ECT) is ever increasing. Initially, anesthetic agents were selected on the basis of their capacity not to antagonize the induced seizure. This was not always a simple task because almost all general anesthetic agents have "in built" antiepileptic activity. Nonbarbiturate agents such as propofol have been successfully used as alternatives to thiopental and methohexitone, but this drug too has antiepileptic properties. Most recently, opioid-like drugs such as remifentanil have been used, and there has been renewed interest in ketamine, a phencyclidine derivative. Attention has also focused on whether the anesthetic agent selected may affect the cognitive impairment seen after ECT. Studies in this area are limited, but early results suggest that agents such as ketamine may have particular benefit. This article reviews the current literature dealing with anesthesia and postoperative cognitive impairment in general and with regard to ECT in particular.

Anesthesia outcomes in a randomized double-blind trial of sevoflurane and thiopental for induction of general anesthesia in electroconvulsive therapy

The purpose of the study was to compare hemodynamics and postanesthetic tolerability of sevoflurane versus thiopental in electroconvulsive therapy (ECT). The design was a randomized double-blind trial in the ECT suite of a tertiary referral medical center. Thirty-one patients were randomized to either sevoflurane or thiopental induction of anesthesia for up to 6 of each subject's ECT treatments. Measurements included hemodynamics (heart rate and blood pressure), arrhythmias, posttreatment orientation, time to first breath, and posttreatment side effects. Sevoflurane compared favorably with thiopental in terms of hemodynamics and time to first breath, although there was a slightly nonsignificant trend toward faster recovery with sevoflurane. Sevoflurane was associated with significantly better postictal orientation 20 minutes after the treatment. We conclude that inhalational anesthesia with sevoflurane presents a well-tolerated alternative for ECT anesthesia.

Propofol and methohexital as anesthetic agents for electroconvulsive therapy: a randomized, double-blind comparison of electroconvulsive therapy seizure quality, therapeutic efficacy, and cognitive performance

BACKGROUND

Propofol is often used as an anesthetic agent for electroconvulsive therapy (ECT). Whether the relatively short seizure duration, resulting from the medication, deteriorates the seizure quality and therapeutic outcomes, or whether propofol might be associated with small but significant post-ECT cognitive impairments, is still a subject of controversy. The purpose of our study was to test these hypotheses in comparison with methohexital.

MATERIALS AND METHODS

In a double-blind, controlled study, 50 patients with severe major depression who were to be treated with ECT were randomly assigned to anesthesia with propofol (120.9 +/- 50.0 mg) or methohexital (83 +/- 26.3 mg) and were observed for 2 months. The 2 drugs were compared on the basis of electroencephalography-registered seizure duration, mean blood pressure, as well as pulse frequency, seizure efficacy index, and postictal suppression. Systolic and diastolic blood pressure, and seizure duration and quality were recorded consecutively during ECT treatments. Changes in depressive symptoms and cognitive functions were measured at 5 time points, pre-ECT, after the third to fifth ECT, post-ECT treatment, and at a follow-up examination 2 and 8 weeks after the last ECT treatment.

RESULTS

Patients on propofol showed a significantly lower increase in blood pressure post-ECT (P < 0.001), their seizure duration was comparable to patients on methohexital (P = 0.072), and seizure quality was significantly superior, as was measured by the Postictal Suppression Index (P = 0.020), and comparable to the methohexital group as measured by the Seizure Efficacy Index (P = 0.160). The improvement of depressive symptoms and the improvement in cognitive functions were similar in both groups (with the exception of the results from 2 cognition tests).

CONCLUSIONS

Propofol, as compared with methohexital, results in a more moderate increase in blood pressure and shorter seizure duration. The seizure quality did not differ significantly between the 2 groups. We detected a tendency toward improved cognitive performance after anesthesia with propofol as compared with methohexital, but with statistical significance in only 2 cognition trials. Therefore, propofol is a safe and efficacious anesthetic for ECT treatment.

Seizure length with sevoflurane and thiopental for induction of general anesthesia in electroconvulsive therapy: a randomized double-blind trial

In general, seizure length does not correlate with clinical outcome with electroconvulsive therapy (ECT), but whether markedly short seizures are still therapeutic is unknown. Furthermore, seizure length effects on clinical outcome in ECT may be different among the various anesthetic agents available. Several studies have investigated the use of inhalational anesthesia in ECT with sevoflurane. In general, seizure length when reported has been in the range of typical values encountered in practice. We recently completed a randomized double blind trial with sevoflurane induction compared with thiopental. Seizure duration with sevoflurane anesthesia was 8 seconds shorter than with thiopental for electroencephalogram and 6.4 seconds shorter for motor, the latter just barely missing statistical significance. Absolute values for seizure duration with both sevoflurane and thiopental are well within typical ranges for those seen with the more commonly used methohexital as anesthetic.

The clinical utility of inhalational anesthesia with sevoflurane in electroconvulsive therapy

Anesthesia in electroconvulsive therapy (ECT) almost always is induced with intravenous agents, typically barbiturates, etomidate, or propofol. There are, however, circumstances in which an inhalational agent would be preferable for induction of general anesthesia. These uncommon clinical scenarios include severe needle stick phobia, agitation preventing insertion of an intravenous catheter, and poor tolerance of intravenous induction agents. Among the inhalational agents available, sevoflurane has several properties that make it the most desirable. In this case series, we describe several patients in our ECT practice in whom inhalational induction of general anesthesia with sevoflurane was deemed appropriate. In all patients, this method was well tolerated and offered distinct advantages compared with an intravenous induction agent. We conclude that ECT practitioners should keep this option in mind for select patients.

Sevoflurane as an alternative anaesthetic for electroconvulsive therapy

OBJECTIVES

The aim of this study was to investigate the effects of sevoflurane and propofol used in electroconvulsive therapy (ECT) on hemodynamic variables and duration of seizure activity and recovery profiles.

METHODS

Sixteen patients who were not premedicated, with a mean age 27.1 years, were enrolled in this prospective open trial, receiving a total of 64 ECT treatments. Each patient was given the following 2 anesthetic regimens in random order: In group S, anesthesia was induced with 7% sevoflurane in 100% oxygen at 6 L min fresh gas flow until the loss of consciousness and 1.5 mg kg propofol in group P. Adequate muscle relaxation was achieved with suxamethonium, 1.0 - 1.2 mg kg. Noninvasive mean arterial pressure (MAP) and heart rate (HR) values, duration of motor seizure activity, and recovery times were recorded.

RESULTS

The mean motor seizure duration was significantly longer with sevoflurane (mean [SD]: 43.09 [16.6] s) than with propofol (28.91 [7.9] s; P < 0.05). The MAP 1 minute and 10 minutes after ECT (101.25 [7.5] mm Hg and 100.16 [11.0] mm Hg, respectively) was significantly increased compared with before ECT (94.56 [6.9] mm Hg) in sevoflurane group (P < 0.05). Time to spontaneous breathing, eye opening and obeying commands, and changes in MAP and HR during and after ECT were similar in both regimens.

CONCLUSION

Induction with 7% sevoflurane allows prolonged duration of motor seizures in ECT. We concluded that induction of anesthesia with sevoflurane inhalation is a reasonable alternative for patients undergoing ECT.

Seizure length and clinical outcome in electroconvulsive therapy using methohexital or thiopental

Seizure duration is an extensively studied and controversial indicator of treatment quality in electroconvulsive therapy. Previous research comparing the effect of the barbiturate anesthetics methohexital and thiopental on seizure duration has yielded conflicting results. A recent period of unavailability of methohexital in the United States allowed for retrospective comparison of seizure length as well as clinical improvement in treatment using each agent. Retrospective review was made of 837 treatments administered to 97 patients between January 2, 2002, and May 31, 2003, examining anesthetic, seizure duration, and Global Assessment of Functioning (GAF) scores of inpatients at hospital admission and discharge. Analysis of variance of treatments 2-5 showed no significant effect for anesthetic on seizure duration. Analysis on a treatment-by-treatment basis revealed a marginally significant trend toward shorter EEG seizures in the thiopental group at the second treatment (50.5 +/- 23.6 s vs. 61.1 +/- 27.9 s; P = 0.07) and fifth treatment (41.7 +/- 16.9 s vs. 51.8 +/- 24.0 s; P = 0.07). A difference approaching statistical significance revealed shorter convulsion length in the thiopental group at treatment 5 (29.0 +/- 12.3 s vs. 34.8 +/- 12.3 s; P = 0.07). Comparison of GAF score improvement at hospital discharge revealed no significant difference (GAF increase 26.4 +/- 9.4 for methohexital-treated patients vs. 24.8 +/- 12.0 for thiopental-treated patients; t = 1.00, df = 82, P > 0.1). Trends approaching significance in treatments 2 and 5 revealed shorter seizures in the thiopental group. However, data on clinical recovery reveals no greater improvement in the methohexital group. Thus, this study calls further into question the premise that choice of barbiturate anesthetic may affect clinical efficacy.