Effect of methohexitone and propofol with or without alfentanil on seizure duration and recovery in electroconvulsive therapy

Alfentanil Pretreatment for Electroconvulsive Therapy-Associated Hemodynamic Lability: A Prospective Randomized Crossover Trial

OBJECTIVES

Electroconvulsive therapy (ECT) is frequently associated with significant hemodynamic changes that increase myocardial oxygen demand including significant hypertension poststimulus. This raises concern about the cumulative effect of repetitive stress from ECT. Historically, various agents have been used to blunt this response and reduce hemodynamic fluctuations in these patients with varying degrees of efficacy. We hypothesized that bolus alfentanil administration timed with the ECT stimulus may reduce near-term hypertension and heart rate (HR) increases in patients undergoing ECT.

METHODS

A randomized, double-blind, placebo-controlled AB/BA crossover trial of 87 patients 18 years or older with mood disorders was carried out. Patients received a standardized anesthetic regimen including induction with methohexital and succinylcholine and were randomized to receive either 20 μg/kg ideal bodyweight of alfentanil or placebo 60 seconds before the ECT stimulus for the first treatment and then crossed over to the other group for the second treatment. The primary outcome was the within-individual difference in preinduction systolic blood pressure and the first systolic blood pressure after the ECT stimulus.

RESULTS

Eighty-seven patients completed the protocol. The primary outcome of increase in systolic blood pressure pre-ECT to post-ECT was 16.9 mm Hg less in the alfentanil group than the placebo group (95% confidence interval, -26.0 to -7.8; P < 0.001). The maximum HR was 6.5 beats per minute lower (95% confidence interval, -12.1 to -0.9; P = 0.024) when patients received alfentanil compared with placebo.

CONCLUSIONS

Premedication with alfentanil reduces poststimulus hypertension and increased HR in patients receiving ECT and therefore, may reduce morbidity related to this in susceptible patients.

A Narrative Overview of Current Anesthetic Drugs in Electroconvulsive Therapy

Electroconvulsive therapy (ECT) is a definitive treatment for patients with psychiatric disorders that are severe, acute, or refractory to pharmacologic therapy. Providing anesthesia for ECT is challenging, as the effect of drugs on hemodynamics, seizure duration, comfort, and recovery must be considered. We highlight and aim to review the common anesthetics used in ECT and related evidence. While drugs such as methohexital, succinylcholine, and etomidate have been used in the past, other drugs such as dexmedetomidine, ketamine, and remifentanil may provide a more balanced anesthetic with a greater safety profile in select populations. Overall, it is essential to consider the patient’s co-morbidities and associated risks when deciding on an anesthetic drug.

Comparison of the target-controlled infusion and the manual infusion of propofol anesthesia during electroconvulsive therapy: an open-label randomized controlled trial

BACKGROUND

Target-controlled infusion (TCI) of propofol is a well-established method of procedural sedation and has been used in Japan for anesthesia during electroconvulsive therapy (ECT). However, the usefulness of the TCI of propofol for ECT has yet to be determined. This study aimed to compare the TCI and manual infusion (MI) of propofol anesthesia during ECT.

METHODS

A total of forty psychiatric inpatients receiving bitemporal ECT were enrolled in the present study and randomized into the TCI group (N = 20) and the MI group (N = 20). Clinical Global Impression (CGI) and Montreal Cognitive Assessment (MoCA) scores were measured before and after ECT. The clinical outcomes, anesthesia-related variables, and ECT-related variables were compared between the two groups. Generalized estimating equations (GEEs) were used to model the comparison throughout the course of ECT.

RESULTS

A total of 36 subjects completed the present study, with 18 subjects in each group. Both the groups didn't significantly differ in the post-ECT changes in CGI and MoCA scores. However, concerning MoCA scores after 6 treatments of ECT, the MI group had improvement while the TCI group had deterioration. Compared with the MI group, the TCI group had higher doses of propofol, and longer procedural and recovery time. The TCI group seemed to have more robust seizures in the early course of ECT but less robust seizures in the later course of ECT compared with the MI group.

CONCLUSIONS

The present study does not support the use of TCI of propofol for anesthesia of ECT.

TRIAL REGISTRATION

(ClinicalTrials.gov): NCT03863925 . Registered March 5, 2019 - Retrospectively registered.

Thiopental is better than propofol for electroconvulsive therapy

Background and aim of the work:

electroconvulsive therapy is a psychiatric procedure requiring general anesthesia. The choice of the hypnotic agent is important because the success of the intervention is associated to the occurrence and duration of motor convulsion. However, all available anesthetic agents have anti-convulsant activity. We compared the effect of thiopental and propofol on seizures.

Methods:

We designed a retrospective study at Mood Disorders Unit of a teaching Hospital. Fifty-six consecutive patients undergoing electroconvulsive therapy were enrolled. Patients received fentanyl followed by either thiopental or propofol. We evaluated the incidence and the duration of seizure after electric stimulus at the first session of electroconvulsive therapy for each patient. Adverse perioperative effects were recorded.

Results:

Patients were 60±12.1 years old and 64% was female. There was a statistically significant higher number of patients who had motor convulsion activity in the thiopental group when compared to the propofol group (25 vs 13, p=0.023). Seizure duration was statistically significant longer in the thiopental group than in the propofol group (35 sec vs 11 sec, p=0.046). No hemodynamic instability, oxygen desaturation episodes, prolonged recovery time from anesthesia and adverse effects related to anesthesia were recorded.

Conclusions:

Thiopental induction has a favourable effect on seizure when compared to propofol in patients undergoing electroconvulsive therapy. (www.actabiomedica.it)

Premedication effect of dexmedetomidine and alfentanil on seizure time, recovery duration, and hemodynamic responses in electroconvulsive therapy

Introduction:

Electroconvulsive therapy (ECT) is an effective treatment for many mental disorders, especially severe and persistent depression, bipolar disorder, and schizophrenia. The aim of this study is to compare the effect of dexmedetomidine and alfentanil on agitation, satisfaction, seizure duration, and patients hemodynamic after ECT.

Materials and Methods:

In a three phase crossover randomized clinical trial, 75 patients aged between 18 and 50 years and candidate for ECT were enrolled and assigned into three groups (25 patients in each group). All patients, respectively, took premedication of dexmedetomidine, alfentanil, or saline in three consecutive phases. Patients received 0.5 μg/kg dexmedetomidine, 10 μg/kg alfentanil or normal saline intravenously, 10 min before induction. Finally, seizure and recovery duration, satisfaction and agitation score, and hemodynamic parameters were evaluated.

Results:

There was no significant difference about seizure duration, agitation score, and hemodynamic parameters between groups but recovery duration was significantly lower in the control group than dexmedetomidine (P = 0.016) and alfentanil group (P = 0.0001). Patients’ satisfaction was significantly higher in intervention groups (alfentanil and dexmedetomidine groups) (P = 0.0001).

Conclusion:

Given the equal effects of alfentanil and dexmedetomidine, it seems that choosing one of these two drugs for premedication of patients undergoing ECT is appropriate. Drug choice is influenced by numerous factors such as accessibility of each drug and the dominance of anesthesiologist and psychiatrist.

Alfentanil anesthetic augmentation lengthens seizure duration in electroconvulsive therapy with older people

Electroconvulsive therapy (ECT) prescription rates rise with age, making it important that treatments be made as effective and safe as possible (Plakiotis et al., 2012). Older people are vulnerable to post-treatment confusion and to subsequent deficits in attention, new learning, and autobiographical memory (Gardner and O'Connor, 2008). Strategies to minimize cognitive side-effects include unilateral electrode placement and stimulus dose titration whereby electrical charge is individually calibrated to seizure threshold (Sackeim et al., 2000). It remains the case, however, that threshold levels typically rise over the treatment course, leading to an increase both in delivered charge and the risk of adverse sequelae.

The Psychiatric Patient as a Health Resource Consumer: Costs Associated with Electroconvulsive Therapy

BACKGROUND

Clinical practice protocols should consider both the psychological criteria related to a patient's satisfaction as a consumer of health services and the economic criteria to allocate resources efficiently. An electroconvulsive therapy (ECT) program was implemented in our hospital to treat psychiatric patients. The main objective of this study was to determine the cost associated with the ECT sessions implemented in our hospital between 2008 and 2014. A secondary objective was to calculate the cost of sessions that were considered ineffective, defined as those sessions in which electrical convulsion did not reach the preset threshold duration, in order to identify possible ways of saving money and improving satisfaction among psychiatric patients receiving ECT.

METHODS

A descriptive analysis of the direct health costs related to ECT from the perspective of the public health system between 2008 and 2014 was performed using a retrospective chart review. All of the costs are in euros (2011) and were discounted at a rate of 3%. Based on the base case, a sensitivity analysis of the changes of those variables showing the greatest uncertainty was performed.

RESULTS

Seventy-six patients received 853 sessions of ECT. The cumulative cost of these sessions was €1409528.63, and 92.9% of this cost corresponded to the hospital stay. A total of €420732.57 (29.8%) was inefficiently spent on 269 ineffective sessions. A sensitivity analysis of the economic data showed stable results to changes in the variables of uncertainty.

CONCLUSION

The efficiency of ECT in the context outlined here could be increased by discerning a way to shorten the associated hospital stay and by reducing the number of ineffective sessions performed.

Different regimens of intravenous sedatives or hypnotics for electroconvulsive therapy (ECT) in adult patients with depression

BACKGROUND

Depression is a common mental disorder. It affects millions of people worldwide and is considered by the World Health Organization (WHO) to be one of the leading causes of disability. Electroconvulsive therapy (ECT) is a well-established treatment for severe depression. Intravenous anaesthetic medication is used to minimize subjective unpleasantness and adverse side effects of the induced tonic-clonic seizure. The influence of different anaesthetic medications on the successful reduction of depressive symptoms and adverse effects is unclear.

OBJECTIVES

This review evaluated the effects of different regimens of intravenous sedatives and hypnotics on anti-depression efficacy, recovery and seizure duration in depressed adults undergoing ECT.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 12); MEDLINE via Ovid SP (from 1966 to 31 December 2012); and EMBASE via Ovid SP (from 1966 to 31 December 2012). We handsearched related journals and applied no language restrictions.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and cross-over trials evaluating the effects of different intravenous sedatives and hypnotics for ECT. We excluded studies and trials using placebo or inhalational anaesthetics and studies that used no anaesthetic.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. When possible, data were pooled and risk ratios (RRs) and mean differences (MDs), each with 95% confidence intervals (CIs), were computed using the Cochrane Review Manager statistical package (RevMan).

MAIN RESULTS

We included in the review 18 RCTs (599 participants; published between 1994 and 2012). Most of the included trials were at high risk of bias.We analysed the results of studies comparing six different intravenous anaesthetics.Only a few studies comparing propofol with methohexital (four studies) and with thiopental (three studies) could be pooled.No difference was noted in the reduction of depression scores observed in participants treated with propofol compared with methohexital (low-quality evidence). These four studies were not designed to detect differences in depression scores.The duration of electroencephalograph (EEG) and of motor seizures was shorter in the propofol group compared with the methohexital group (low-quality evidence). No difference was seen in EEG seizure duration when propofol was compared with thiopental (low-quality evidence).Time to recovery (following commands) was longer among participants after anaesthesia with thiopental compared with propofol (low-quality evidence).For the remaining comparisons of anaesthetics, only single studies or insufficient data were available. Adverse events were inadequately reported in eligible trials, and none of the included trials reported anaesthesia-related mortality.

AUTHORS' CONCLUSIONS

Most of the included studies were at high risk of bias, and the quality of evidence was generally low. The studies were not designed to detect clinically relevant differences in depression scores. Anaesthetic agents should be chosen on the basis of adverse effect profile, emergence and how these medications affect seizure duration. If it is difficult to elicit an adequately long seizure, methohexital may be superior to propofol (low-quality evidence). If a patient is slow to recover from anaesthesia, propofol may allow a faster time to follow commands than thiopental (low-quality evidence). A factor of clinical concern that was not addressed by any study was adrenal suppression from etomidate. Optimal dosages of intravenous sedatives or hypnotics have not yet been determined.Larger well-designed randomized studies are needed to determine which intravenous anaesthetic medication leads to the greatest improvement in depression scores with minimal adverse effects.

The effect of propofol-remifentanil anesthesia on selected seizure quality indices in electroconvulsive therapy

BACKGROUND

Use of a short-acting opiate to potentiate anesthetic induction agents has been shown to increase seizure duration in electroconvulsive therapy (ECT), but little is known of the effect of this combination on indices of seizure quality.

OBJECTIVE

To determine whether anesthetic modality affects commonly provided indices of seizure quality.

METHODS

Twenty-five subjects were given propofol 2 mg/kg body weight for their first ECT session, at which time seizure threshold was titrated. Subjects thereafter alternated between that anesthetic regimen or propofol 0.5 mg/kg plus remifentanil 1 mcg/kg. Linear mixed models with random subject effect, adjusting for electrode placement, electrical charge, and number of treatments, were fit to estimate effect of anesthesia on seizure duration and several standard seizure quality indices (average seizure energy, time to peak electroencephalography (EEG) power, maximum sustained power, interhemispheric coherence, early and midictal EEG amplitude, and maximum sustained interhemispheric EEG coherence).

RESULTS

Propofol-remifentanil anesthesia significantly lengthened seizure duration and was associated with longer time to reach maximal EEG power and coherence as well as maximal degree of interhemispheric EEG coherence. No effect was seen on early ictal amplitude or average seizure energy index.

CONCLUSIONS

Propofol-remifentanil anesthesia prolongs seizure duration and has a significant effect on some, but not all, measures of seizure quality. This effect may be of some benefit in cases where adequate seizures are otherwise difficult to elicit. Varying anesthetic technique may allow more precise investigation of the relationships between and relative impacts of commonly used seizure quality indices on clinical outcomes and ECT-related cognitive side effects.

The difficult-to-treat electroconvulsive therapy patient - Strategies for augmenting outcomes

BACKGROUND

Several treatment strategies for augmenting outcomes with ECT (concurrent antidepressant treatment, frequency of ECT treatments, hyperventilation and use of remifentanil) are discussed in the context of a difficult clinical case, accompanied by a review of the relevant existing literature.

METHODS

Literature on the above aspects of ECT technique was identified via a PubMed search and was critically reviewed.

RESULTS

There is preliminary evidence that concurrent administration of some antidepressant medications may be useful in the highly treatment resistant patient, though due attention should be given to potential risks in combining these with ECT; reduction of the treatment frequency to twice a week; hyperventilation prior to each treatment; and the use of remifentanil to minimise the dosage of induction anaesthetics with anticonvulsant properties, may be useful strategies to enhance seizure production in cases where a high or rapidly rising seizure threshold is a major impediment to ECT treatment.

LIMITATIONS

It should be noted that empirical evidence for the effectiveness of each of the above strategies in producing better outcomes with ECT is not definitive, pointing to the need for further research in these areas.

CONCLUSIONS

The above strategies may be useful in clinical ECT practice, particularly in patients who are apparently treatment resistant, but the practitioner should be aware that the level of evidence underpinning these approaches is at present, preliminary.

Remifentanil/Thiopental combination and seizure length in electroconvulsive therapy

In an effort to see if use of high-potency opioid combined with lower-than-usual dose barbiturate results in longer seizure length in electroconvulsive therapy, we retrospectively examined data from 56 patients. For each case, 1 seizure with thiopental alone and 1 with thiopental combined with remifentanil were compared. Longer mean electroencephalographic seizure length with the combination slightly missed statistical significance, whereas motor seizure duration was not statistically significantly different between the 2 strategies. We conclude that if thiopental is used for anesthetic induction in electroconvulsive therapy in the dose range described herein, modest dose reduction and combination with remifentanil does not reliably prolong seizure duration.

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.

Effects of the addition of remifentanil to propofol anesthesia on seizure length and postictal suppression index in electroconvulsive therapy

OBJECTIVE

Propofol is a widely used anesthetic agent for electroconvulsive therapy (ECT). However, there are concerns that its anticonvulsant effect may interfere with the efficacy of ECT. We aimed to investigate the effects on seizure activity of the addition of the opiate remifentanil to propofol anesthesia for ECT.

METHODS

A retrospective analysis of 633 treatments in 73 patients was conducted. At each treatment, patients had received anesthesia with propofol alone or propofol plus remifentanil, depending on which anesthetist was providing anesthesia. Analysis of variance was performed to examine the effects of the anesthetic used, the electrode placement, the dose of electricity administered, and the stage in the course of treatment. Dependent variables were electroencephalogram seizure length and postictal suppression index (PSI).

RESULTS

Addition of remifentanil resulted in a small but significantly lower dose of propofol being used to induce unconsciousness. Addition of remifentanil affected seizure length, mainly related to an effect when placement was right unilateral (F = 5.70; P = 0.017). There was also a significantly increased PSI (F = 4.3; P = 0.039), which was not dependent on dose or on placement.

CONCLUSIONS

The data suggest that addition of remifentanil to propofol anesthesia significantly alters seizure indices. This may be secondary to a reduction in the amount of propofol required or to an independent effect of remifentanil. The increase in PSI in particular suggests that addition of remifentanil may improve clinical response. However, this can only be examined in a randomized controlled trial.

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.

Anästhesiologische Aspekte bei Elektrokrampftherapie

Electroconvulsive therapy (ECT) is used in the therapy of severe psychiatric disorders. The treatment, in which a generalized epileptic seizure is provoked by electrical stimulation of the brain, is performed under anaesthesia and muscle relaxation. Considering careful previous clinical examination and anaesthesiological and internal contraindications, ECT is a safe form of treatment. The following review is intended to familiarize with ECT and to provide advice for the anaesthesiological management.

Effects of landiolol on hemodynamic response and seizure duration during electroconvulsive therapy

PURPOSE

This study was done to evaluate the effect of landiolol, an ultra-short-acting beta-blocker, on the hemodynamic response and the duration of seizure activity during electroconvulsive therapy (ECT).

METHODS

We designed a prospective, randomized, double-blinded, placebo-controlled, crossover study. Fourteen psychiatric patients participated. Landiolol (0.1 mg x kg(-1) or 0.2 mg x kg(-1)) or saline (placebo) was administered IV 1 min before the induction of anesthesia. Unconsciousness was induced with propofol 1.0 mg x kg(-1) IV, and muscle paralysis was produced with succinylcholine 0.6 mg x kg(-1) IV. Subsequently, electrical stimulus was administered to elicit a seizure, and the duration of the motor seizure activity was noted.

RESULTS

The heart rate (HR) and rate-pressure product (RPP) before ECT were significantly decreased in the 0.2 mg x kg(-1) landiolol group compared with these parameters in the placebo and 0.1 mg x kg(-1) landiolol groups. Both the 0.1 mg x kg(-1) and 0.2 mg x kg(-1) doses significantly attenuated the degree of tachycardia and RPP after ECT in comparison with the placebo group. Pretreatment with 0.2 mg x kg(-1) landiolol resulted in a significantly shorter duration of motor seizure than that in the placebo group (21 +/- 13 s vs 27 +/- 12 s).

CONCLUSION

As the landiolol dose of 0.2 mg x kg(-1) caused shorter seizure duration, and because the hemodynamic effects after ECT of the 0.1 mg x kg(-1) and 0.2 mg x kg(-1) doses were similar, it was concluded that a 0.1 mg x kg(-1) landiolol bolus was the appropriate dose pretreatment before ECT.

Bispectral index-controlled anaesthesia for electroconvulsive therapy*

BACKGROUND

The suggested induction dose of methohexital for electroconvulsive therapy (ECT) varies widely influencing efficacy of ECT and safety of anaesthesia. Bispectral index (BIS), a monitor of consciousness, may be useful to assure adequate hypnosis with optimized methohexital dose.

METHODS

Patients with medically resistant major depression (ICD10), scheduled for multiple ECT's, were studied. Depth of anaesthesia was BIS controlled. ECT was not performed until BIS dropped below 50. Initially anaesthesia was induced with methohexital 1.0 mg kg(-1), and stepwise reduced by 0.1 mg kg(-1) during consecutive treatments. If BIS did not drop below 50, the methohexital was supplemented by further boluses of 0.5 mg kg(-1), until the desired level of hypnosis was reached. The adequacy of the anaesthetic recommendation for methohexital (1.0-1.5 mg kg(-1)) as well as the psychiatric recommendation (0.75-1 mg kg(-1)) was investigated.

RESULTS

One-hundred and nine ECT's in 14 patients were studied. The recommended anaesthetic dose (1.0-1.5 mg kg(-1)) was inadequate in 40% of the treatments, with 12% exceeding 1.5 mg kg(-1), and 28% below 1.0 mg kg(-1). Psychiatric recommendation (0.75-1.0 mg kg(-1)) was inadequate in 49%, with 39% exceeding 1.0 mg kg(-1) and 10% undershooting at 0.75 mg kg(-1).

CONCLUSIONS

Methohexital for ECT showed a great variability, exceeding as well as undershooting the dosage recommendations widely. BIS monitoring may be useful to secure adequate hypnosis during muscle relaxation and treatment and may optimize ECT efficacy.

Guide to anaesthetic selection for electroconvulsive therapy

Electroconvulsive therapy (ECT) is used in the treatment of severe psychiatric disorders. It involves the induction of a seizure for therapeutic purposes by the administration of a variable-frequency electrical stimulus via electrodes applied to the scalp. The original application of ECT in non-anaesthetised patients resulted in many traumatic effects and was replaced, in the early 1960s, with a modified ECT regimen that used anaesthesia with neuromuscular blockade. This remains the worldwide standard today. The development of modern ECT devices, with improved impulse modes, has also reduced the incidence of post-interventional cognitive adverse effects. The variety of centrally-acting co-medications administered and the cardiovascular effects occurring during the procedure make patients receiving ECT a challenge for the anaesthetist. The efficacy of ECT depends on the production of adequate seizures; however, the anaesthetic agents commonly used during ECT suppress the generation of convulsions. Therefore, the efficacy of ECT requires knowledge of anaesthetic precepts, understanding of the interaction between anaesthetic drugs and seizure activity, and awareness of the physiological effects of ECT as well as the treatment of those effects. Successful and safe ECT depends on the correct choice of anaesthetic drugs for the individual patient, which have to be chosen with respect to the individual concomitant medication and pre-existing diseases. This review provides information for the optimal selection, set-up and practice of anaesthetic drug treatment in ECT.

Effects of remifentanil and alfentanil on seizure duration, stimulus amplitudes and recovery parameters during ECT

BACKGROUND AND OBJECTIVE

Propofol may decrease seizure duration in electroconvulsive therapy. Although not proven, prolonged seizures may be more efficacious. The goal of this study was to evaluate and compare effects of alfentanil and remifentanil on seizure duration, recovery parameters and degree of stimulus amplitude in patients undergoing electroconvulsive therapy.

METHODS

Twenty-four ASA I-II patients enrolled in this prospective, randomized trial, each receiving a total of seven electroconvulsive therapies. Patients were randomized to receive only Propofol, group P (0.75 mg kg-1, n=8), Propofol with alfentanil, group A (10 microg kg-1 alfentanil+0.5 mg kg-1 Propofol, n=8) and Propofol with remifentanil, group R (1 microg kg-1 remifentanil +0.5 mg kg-1 propofol, n=8) via an iv route. Supplemental doses of propofol were given as required to achieve loss of consciousness. Succinylcholine 0.5 mg kg-1 iv was given to all groups for muscular paralysis. We recorded hemodynamic parameters, cortical and motor seizure durations, and recovery parameters.

RESULTS

Mean motor seizure duration was found to be significantly longer in patients receiving propofol-remifentanil anesthesia (53.3+/-13.6 s) and propofol-alfentanil anesthesia (52.2+/-0.4 s) compared with propofol anesthesia (37.6+/-9.2 s) (P=0.001). Recovery parameters and stimulus amplitudes were similar in groups A and R; significantly different from group P (P=0.001).

CONCLUSIONS

Adding 10 microg kg-1 alfentanil or 1 microg kg-1 remifentanil to reduced doses of propofol provided unconsciousness and increased seizure durations. For patients who need higher stimulus amplitudes for longer seizure durations, combining low-dose propofol with alfentanil or remifentanil may be good alternative regimens for ECT.

The comparative hemodynamic effects of methohexital and remifentanil in electroconvulsive therapy

Remifentanil is a short acting opioid frequently used to supplement general anesthesia for brief procedures. Narcotic agents are known for their ability to blunt autonomic responses to stimuli such as laryngoscopy and intubation and do not alter seizure threshold. We hypothesized that the combination of remifentanil and methohexital for induction would produce favorable suppression of sympathetic response during electroconvulsive therapy (ECT). With Institutional Review Board approval and informed consent, patients were enrolled in a prospective, randomized, double-blind, crossover study of methohexital alone versus remifentanil with an adjuvant of low-dose methohexital. One hundred ten ECT treatments were evaluated and subjects were treated in an alternating fashion with one of two induction protocols: Methohexital alone in an 80-100 mg IV bolus or remifentanil 500 mcg IV bolus combined with methohexital 40 mg IV. Bilateral ECT was performed in standard fashion and systolic blood pressure and heart rate were recorded throughout the procedure. No significant differences were found in baseline hemodynamic values between the two groups. Heart rate was significantly lower in the remifentanil group versus methohexital group at one minute post-induction and just prior to ECT stimulus. Pre-ECT systolic blood pressure was not significantly different between the two groups. Heart rate remained lower in the remifentanil group at all measured timepoints during the treatment and continuously for five minutes after the seizure. Systolic blood pressure was significantly lower at one minute following the end of seizure and five minutes after end of seizure. Remifentanil's short duration of action, favorable side effect profile, potential proconvulsant activity and ability to suppress hemodynamic response make it a potential novel drug for ECT induction.

A retrospective comparison of remifentanil versus methohexital for anesthesia in electroconvulsive therapy

The electroconvulsive therapy (ECT) service at West Virginia University conducted a retrospective analysis of 24 patients who received bilateral ECT between November 1998 and December 2003. Patients were treated with a standard methohexital-based anesthetic. Twenty-four patients became completely or relatively refractory to maximum settings on the ECT device and were then switched to remifentanil as the sole induction agent. Seizure threshold was established by stimulus dose retitration. Stimulus dose in total charge (mC) and dynamic energy (J) was significantly lower with the remifentanil anesthetic versus methohexital. (P < 0.0001) Resulting motor and EEG seizure duration in patients was significantly longer receiving the remifentanil anesthetic versus methohexital. (P < 0.0001) Previous reports describe a rise in seizure threshold in patients for repeated ECT. Although this rise occurred during the treatment course using a methohexital anesthetic, this effect was greatly diminished when remifentanil was used as the sole anesthetic agent. We conclude that remifentanil can provide improved seizure response to ECT in patients who are refractory to seizure induction after a standard methohexital anesthetic. We also conclude that the increase in stimulus dose typically required with repeated treatments is related to the anesthetic regimen.

Combination propofol-alfentanil anesthesia for electroconvulsive therapy in patients receiving monoamine oxidase inhibitors

Two patients who had failed outpatient treatment of depression were given electroconvulsive therapy while simultaneously being treated with monoamine oxidase inhibitors. Both were administered propofol-alfentanil anesthesia without complications.

Double-blind placebo controlled study of the effects of etomidate-alfentanil anesthesia in electroconvulsive therapy

The effect of etomidate and alfentanil on heart rate, systolic arterial pressure, diastolic arterial pressure, and mean arterial pressure was compared with etomidate and placebo during electroconvulsive therapy (ECT). We also studied the influence of alfentanil on seizure duration using both the cuff method and 2-lead electroencephalographs on the prevention of myoclonus induction by etomidate, on duration of apnea and on postictal agitation after ECT. We enrolled 21 consecutive patients in a prospective placebo-controlled, within patient blocked randomized study. Alfentanil significantly reduced heart rate, diastolic arterial pressure, and mean arterial pressure both before and after the stimulus. The increase in these variables during the convulsion was not affected, compared with placebo. Alfentanil had no effect on seizure duration. However, apnea duration was prolonged during the alfentanil sessions as compared with placebo (73 seconds). Alfentanil did not significantly reduce the occurrence of myoclonus after etomidate as compared with placebo, nor did postictal agitation after ECT appear more often with alfentanil. Alfentanil could be useful to reduce tachycardia and hypertension during ECT in high-risk patients without effects on seizure duration. Alfentanil itself has no proconvulsive effect in combination with etomidate.

The comparative effects of sevoflurane and methohexital for electroconvulsive therapy

The standard anesthetic agent for electroconvulsive therapy (ECT) has been methohexital. We compared sevoflurane, a short-acting halogenated anesthetic, to methohexital for induction in ECT. Twelve subjects received sevoflurane or methohexital on alternating treatment days. Seizure duration, time to administering ECT, emergence and recovery, as well as several hemodynamic measures were recorded. A total of 69 treatments were analyzed. When sevoflurane was used, seizure durations recorded by observation and by EEG, were shorter by 10 and 23 seconds, respectively. With sevoflurane, seizure duration remained, however, within a clinically acceptable range. Methohexital allowed faster administration of ECT and discharge from the recovery room (3.8 vs. 6.2 minutes and 40.8 vs. 47.0 minutes, respectively). No difference in the post-ECT hemodynamic changes was found between the two treatments. We conclude that, when indicated, sevoflurane could provide a suitable alternative treatment option to methohexital, but some limitations, including shortened seizure duration and potential side effects, should be kept in mind.

Seizure duration with remifentanil/methohexital vs. methohexital alone in middle-aged patients undergoing electroconvulsive therapy

BACKGROUND

The object of this study was to test whether substituting part of the methohexital dose with the short-acting opioid remifentanil would prolong seizure duration in middle-aged patients while providing a similar depth of anesthesia as with methohexital alone. This has been reported for the combined use of methohexital and remifentanil in elderly patients, but has not been investigated in middle-aged patients likely to require a higher total dose of methohexital for inducing anesthesia.

METHOD

Seven patients (42+/-10 years; mean +/-SD) receiving electroconvulsive therapy (ECT) were anesthetized with methohexital (1.25 mg kg-1) or with methohexital (0.625 mg kg-1) plus remifentanil (1 micro g kg-1) in this randomized, double blind, crossover study. Additional methohexital was given as needed until loss of eyelash reflex was observed. Suxamethonium (1 mg kg-1) was used for muscular paralysis.

RESULTS

Motor and EEG seizure durations were significantly longer after induction with methohexital plus remifentanil (45+/-14 and 58+/-15 s) than with methohexital alone (31+/-11 and 42+/-18 s). A methohexital dose of 1.2+/-0.3 and 1.9+/-0.3 mg was necessary to achieve loss of eyelash reflex if methohexital was used with and without remifentanil. Peak heart rate after ECT was significantly higher if remifentanil was coadministered with methohexital (148+/-12 vs. 126+/-24 b.p.m).

CONCLUSION

Substituting part of the methohexital dose with remifentanil is a useful anesthetic technique to prolong seizure duration in middle-aged patients requiring a 1.5-fold higher induction dose of methohexital than elderly patients, the only population studied to date for the combined use of methohexital and remifentanil in ECT.

The effect of remifentanil on seizure duration and acute hemodynamic responses to electroconvulsive therapy

We designed this prospective, randomized, double-blinded, placebo-controlled, crossover study to evaluate the effect of different doses of remifentanil on the acute hemodynamic response and duration of seizure activity after a standardized electroconvulsive therapy (ECT) stimulus. Twenty consenting patients with major depressive disorders receiving maintenance ECT participated in this study. Eighty ECT treatments were evaluated. All patients were premedicated with glycopyrrolate 0.2 mg IV, unconsciousness was induced with methohexital 1 mg/kg IV, and muscle paralysis was produced with succinylcholine 1.2 mg/kg IV. Subsequently, patients received 1 of 3 different doses of remifentanil 25, 50, and 100 microg or saline (control) in a random sequence immediately after methohexital at 4 consecutive ECT treatments. Labetalol, in 5-mg IV boluses, was used as a rescue antihypertensive medication. A fixed suprathreshold electrical stimulus was administered to elicit a seizure, and the times from the stimulus to the cessation of the motor and electroencephalographic (EEG) seizure activity were noted. Pre- and post-ECT blood pressure values were significantly decreased in the 100- microg remifentanil group compared with the control group. The durations of motor (38 +/- 9 s to 43 +/- 15 s) and EEG (55 +/- 29 s to 60 +/- 21 s) seizure activity were not significantly different among the four groups. Similarly, recovery times to eye opening, obeying commands, and discharge from the recovery room did not differ among the four study groups. The requirement for labetalol after ECT was nonsignificantly decreased in the remifentanil groups. In conclusion, remifentanil 100 microg IV attenuated the acute hemodynamic response to ECT. Furthermore, remifentanil had no adverse effect on the duration of ECT-induced seizure activity. Finally, adjunctive use of remifentanil did not prolong recovery times or increase post-ECT side effects.

IMPLICATIONS

Remifentanil (100 microg IV) attenuated the acute hemodynamic response after electroconvulsive therapy (ECT) without adversely affecting the length of the ECT-induced seizure activity or prolonging recovery times.

Augmentation of seizure induction in electroconvulsive therapy: a clinical reappraisal

OBJECTIVE

Missed or abortive seizures during electroconvulsive therapy (ECT) may preclude completion of an effective course of treatment in some cases. Seizure augmentation, using proconvulsant agents, has been used to overcome resistance to the induction and continuation of seizure activity. In this review, we analyze published clinical data on the effects and safety of seizure augmentation techniques.

METHOD

Clinical studies and case reports were obtained through a MEDLINE literature search from 1966 to 2001, cross-referencing ECT and proconvulsant agents. Article references were also scanned for relevant studies.

RESULTS AND CONCLUSIONS

Data from clinical trials indicate that augmentation facilitates seizure induction when maximal electrical stimuli fail. Anesthetic modifications, including hyperventilation and substitution with etomidate, ketamine, or other agents, often are successful in overcoming seizure resistance and compare favorably with the use of caffeine. In a few studies, augmentation enabled the use of lower stimulus intensities and fewer treatments without loss of efficacy, even in patients not resistant to seizure induction. However, effects of proconvulsants must be reconciled with increasing evidence of the importance of stimulus dosing relative to seizure threshold and other parameters, now considered key to the efficacy of ECT. Further investigations of pharmacologic augmentation could facilitate the administration of ECT and could provide further insights concerning parameters of seizure efficacy and the mechanism of action underlying convulsive therapies.

Effects of combined methohexitone-remifentanil anaesthesia in electroconvulsive therapy

BACKGROUND

Methohexitone is widely used to provide anaesthesia for patients undergoing electroconvulstive therapy (ECT). Short seizure duration, high blood pressures (BP) and heart rates (HR) are usual in elderly patients. In this study, elderly patients undergoing ECT received low dose methohexitone with remifentanil or methohexitone alone and motor seizure duration, haemodynamic response and recovery time were compared.

METHODS

Ten patients, of mean age 74.3 years, were enrolled in this double-blind, randomised crossover trial, receiving a total of 38 ECTs. Each patient was given the following two i.v. regimens in random order: A) methohexitone 0.5 mg kg(-1) combined with remifentanil 1.0 microg kg(-1) and B) methohexitone 0.75 mg kg(-1). Additional methohexitone was given, if needed, until loss of consciousness, and then suxamethonium 1.0 mg kg(-1) for muscular paralysis.

RESULTS

Mean motor seizure duration was significantly longer with methohexitone-remifentanil (37.6 s (SD 12.0)) than with methohexitone alone (27.1 (SD11.5)) (P=0.0009). Recovery time, time to spontaneous breathing, peak postictal changes in BP and HR were similar with both regimens.

CONCLUSION

A reduced dose of methohexitone combined with remifentanil allows prolonged duration of motor seizures in ECT. We conclude that low dose methohexitone combined with a short-acting opioid is a reasonable alternative for elderly patients undergoing ECT, and for other patients with short seizure duration.

Propofol [correction of propfol] versus methohexital for electroconvulsive therapy: a meta-analysis

A systematic search (Medline, Cochrane library, Embase, bibliographies, to 5.2000, no language restriction) was performed for published reports of randomized comparisons of propofol and methohexital for anesthesia during electroconvulsive therapy. We analyzed 15 trials with data on 706 patients. The duration of motor seizure was shorter with propofol (range, 18-39 seconds) than with methohexital (range, 26-48 seconds, weighted mean difference 8.4 seconds [95% CI, 6.6-10.0]). With both propofol and methohexital, there was little evidence of an association between dose and duration of motor seizure (for propofol: r2 = 0.25, P = .08; for methohexital: r2 = 0.11, P = .27). Two small trials investigated clinical outcome; results were inconclusive. Data on adverse effects were sparse. Duration of seizure was not proven to be a useful measure of treatment success in the study of electroconvulsive therapy with propofol or methohexital. The impact of the technique of anesthesia on the underlying disease needs to be established.

Monitoring of the central nervous system

Clinical studies have shown a close relationship between variables such as hypoxia, increased intracranial pressure, arterial hypotension, or seizures and neurological outcome. This indicates the need for monitoring techniques of the central nervous system including measurements of cerebral blood flow, cerebral oxygenation and neuronal function. Semiquantitative changes in cerebral blood flow can be measured continuously using transcranial Doppler sonography. Measurements of jugular venous oxygen saturation or tissue oxygenation reflect the balance between cerebral oxygen delivery and cerebral oxygen demand. Near-infrared spectroscopy appears to be a technology with potential for non-invasive measurements of cerebral oxygen saturation and mitochondrial oxygen availability. The current technology is, however, of limited clinical utility. Brain electrical monitoring techniques such as electroencephalogram and evoked potentials are sensitive and specific to detect changes in neuronal function caused by cerebral ischaemia. Electroencephalogram and evoked potential measurements of depth of anaesthesia and specific electroencephalogram patterns for pharmacodynamic quantification of drug effects may gear the dosage of anaesthetics according to the anaesthetic effect.

Endogenous opiates: 1997

This paper is the twentieth installment of our annual review of research concerning the opiate system. It summarizes papers published during 1997 that studied the behavioral effects of the opiate peptides and antagonists, excluding the purely analgesic effects, although stress-induced analgesia is included. The specific topics covered this year include stress; tolerance and dependence; eating and drinking; alcohol; gastrointestinal, renal, and hepatic function; mental illness and mood; learning, memory, and reward; cardiovascular responses; respiration and thermoregulation; seizures and other neurologic disorders; electrical-related activity; general activity and locomotion; sex, pregnancy, and development; immunologic responses; and other behaviors.