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

The Effect of Remimazolam on Seizure Profile, Hemodynamics, and Recovery in Patients With Electroconvulsive Therapy Comparison With Propofol and Etomidate: A Retrospective Study

OBJECTIVES

To compare seizure-related, hemodynamic, and recovery outcomes when using remimazolam for ECT with those of other anesthetics, specifically propofol and etomidate.

METHODS

A total of 49 patients who underwent 405 ECT treatment sessions under general anesthesia were retrospectively analyzed. Remimazolam, propofol, and etomidate were used for 93, 138, and 174 ECT sessions, respectively. The primary outcome was durations of motor and electroencephalogram (EEG) seizure activity, whereas secondary outcomes included hemodynamics (ie, mean arterial pressure [MAP] and heart rate [HR] at various time points from induction to postanesthesia care unit [PACU] discharge), antihypertensive drugs administration after electrical stimulus, and recovery profiles (ie, length of PACU stay and incidence of postictal confusion).

RESULTS

Durations of motor and EEG seizures were shorter for remimazolam than etomidate (motor, P < 0.001; EEG, P = 0.003) but similar compared with propofol (motor, P = 0.191; EEG, P = 0.850). During seizure, remimazolam showed a comparable MAP and HR to etomidate (MAP: P = 0.806; HR: P = 0.116). The antihypertensive drug use was lowest for remimazolam (6.8%), followed by propofol (35.6%) and etomidate (65.6%), and the mean length of PACU stay was comparable for remimazolam (19.7 min), propofol (22.8 min), and etomidate (24.5 min). The occurrence of postictal confusion did not differ among the 3 agents (P > 0.050).

CONCLUSIONS

Remimazolam is a promising anesthetic option for ECT because of its comparable seizure profiles, stable hemodynamics, and comparable PACU stay when compared with propofol and etomidate without additional adverse events.

Assessment of seizure duration and utility of using SedLine® EEG tracing in veterans undergoing electroconvulsive therapy: a retrospective analysis

BACKGROUND

Electroconvulsive therapy (ECT) endures as a definitive treatment for refractory depression and catatonia and is also considered an effective treatment for a number of other severe psychiatric disorders (Lisanby, N Engl J Med 357:1939-1945, 2007)(Weiner and Prudic, Biol Psychiatry 73:105-106, 2013). GA is an essential component of the ECT procedure for various reasons (Lee, Jenkins and Sparkle, Life 11, 2021). Monitoring anesthetic effects on the brain is desirable as anesthetic agents affect seizure duration and recovery (Rasulo, Hopkins, Lobo, et al,  Neurocrit Care 38:296-311, 2023) (Jones , Nittur , Fleming and Applegate,  BMC Anesthesiol 21:105, 2021) (Soehle , Kayser , Ellerkmann and Schlaepfer,  BJA 112:695-702, 2013). Perioperative anesthetic effects on consciousness can be assessed with brain function monitoring using raw electroencephalogram (EEG) traces and processed EEG indices.

OBJECTIVE

We examined the usefulness and utility of the SedLine® anesthetic effect monitor during ECT procedures. We hypothesized that the seizure duration as measured by the EEG tracing of the ECT machine is equivalent to the duration assessed by the SedLine® EEG tracing. A secondary objective was to describe the SedLine® patient state indices (PSI) at different phases of treatment.

METHODS

Following IRB approval, we analyzed the data of the electronic medical records of 45 ECT treatments of 23 patients in an urban VA medical center between July 01, 2021, and March 30, 2022. We compared the seizure duration in minutes and seconds as measured either by the ECT machine EEG tracing or the SedLine® EEG tracing. We then collected SedLine® processed EEG indices at four different stages during the treatment. Appropriate comparative and observational statistical analyses were applied.

RESULTS

There was no significant difference in measured seizure duration between the two methods examined (p < 0.05). We observed a lag of the SedLine PSI value at the time before stimulus delivery and limited PSI utility during the course of ECT.

CONCLUSION

The SedLine® EEG tracing can be an alternative to the machine EEG tracing for the determination of seizure duration. The SedLine® processed EEG indices are not consistently useful before and after ECT delivery. Anesthetic effect monitoring during ECT is feasible.

Acute and Prophylactic Management of Postictal Agitation in Electroconvulsive Therapy

ABSTRACT

Postictal agitation (PIA) is a common adverse effect of electroconvulsive therapy (ECT), a treatment used for a variety of psychiatric disorders. Because of risk of harm to patients and health providers when patients develop PIA, its acute management and prophylaxis are of vital importance for ECT practitioners. This article describes PIA risk factors, as well as practical steps to manage this ECT complication. Nonpharmacologic patient safety interventions are critical components of PIA management. Benzodiazepines, antipsychotics, and additional anesthetic doses are discussed as acute treatment interventions. Prophylactic pharmacologic choices described include antipsychotics, postseizure anesthetics, and dexmedetomidine. Exploratory choices such as melatonin and intranasal formulations of sedatives are also discussed. This review suggests that common medication like olanzapine and propofol are cost-effective considerations to decrease PIA incidence and/or severity after ECT. In addition, dexmedetomidine presents a management alternative for treatment-resistant PIA. This literature review outlines treatment choices while suggesting future directions for considering effective treatments of postictal agitation in clinical settings.

The influence of anaesthetic choice on seizure duration of electroconvulsive therapy; etomidate versus methohexital

Background

Many of the anaesthetic drugs used for electroconvulsive therapy have anticonvulsant properties and may influence efficacy of electroconvulsive therapy. With this study we aim to provide more information on the effect of etomidate and methohexital on seizure duration. We explore the relationship between induction drug, motor and electroencephalography seizure duration. Moreover, we study the relationship of seizure duration and number of therapies.

Methods

In this retrospective study we collected data from patient records from 2005 until 2016. Inclusion criteria were the use of etomidate and/or methohexital and documentation of dosage, electroconvulsive therapy dosage and seizure duration. Exclusion criteria were missing data on either induction drug, dosage or seizure duration.

Results

Thirty seven patients were analysed. The mean age was 52 years and seventy six percent were female. Most patients were suffering from affective disorders (81%). Motor and electroencephalography seizure duration were analysed in 679 and 551 electroconvulsive therapies, respectively. Compared to methohexital, motor and electroencephalography seizures under etomidate were 7 and 13 s longer, respectively. Furthermore, there was a negative association between seizure duration and number of treatment and a negative association between seizure duration and electroconvulsive therapy dosage.

Conclusions

This study demonstrates significant longer motor and electroencephalography seizure duration using etomidate compared to methohexital. Etomidate might therefore increase the effectiveness of electroconvulsive therapy. Moreover, we observed a negative association between seizure duration, number of treatment and electroconvulsive therapy dosage. With this study we contribute to the available literature comparing methohexital and etomidate as induction agents for electroconvulsive therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01745-y.

The superiority of ketofol and etomidate against propofol or thiopental anesthesia for ECT

OBJECTIVES

Most anesthetic drugs used for electroconvulsive therapy (ECT) have dose-dependent anticonvulsive effects, counter-acting seizure induction, lowering seizure quality. However, a consummate drug for ECT anesthesia has not yet been established. Therefore, in this study, we aimed to investigate the effects of etomidate, thiopental, propofol and co-administration of ketamine-propofol (ketofol) on seizure quality and hemodynamic safety.

METHODS

Registries of 121 patients (1077 sessions) were retrospectively evaluated. The effects of anesthetics on ECT-related parameters (stimulation charge, central seizure duration, number of failed stimulation trials, mean arterial pressure, and peak heart rate) were analyzed via linear mixed-effects models.

RESULTS

Overall, the seizure duration decreased, and the stimulation charge increased in time with continuing sessions within a course of ECT. The decrease in seizure duration and the increase in required stimulation charge was significantly lower with etomidate and ketofol. Additionally, ketofol was significantly related to a lower number of failed stimulation trials compared to propofol. Ketofol and propofol use was associated with a significantly lower postictal mean arterial pressure.

CONCLUSION

Ketofol and etomidate were equivalently superior in the rate of decrease in seizure duration and the required elevation in stimulus charge, which would interpret into valuable clinical guidance, especially for "seizure resistant" patients, and their use may potentially lower ECT related cognitive side effects.

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.

Effects of Propofol and Propofol-Remifentanil Combinations on Haemodynamics, Seizure Duration and Recovery during Electroconvulsive Therapy

Objective

This study aimed to evaluate the effects of adding different doses of remifentanil to propofol treatment compared with propofol alone with regard to parameters, including the seizure duration, haemodynamic changes and recovery time, in patients undergoing electroconvulsive therapy (ECT).

Methods

This study was designed as a self-controlled, prospective, double-blind investigation of 17 patients between the ages of 20 and 65 years who had planned treatment with ECT at a psychiatric clinic. Group P (propofol) was administered 10 mL of normal saline after 0.5 mg kg⁻¹ intravenous (IV) bolus of propofol. Group R I (propofol plus remifentanil-1) was administered 1.5 μg kg⁻¹ of remifentanil, and group R II (propofol plus remifentanil-2) was given 2 μg kg⁻¹ of remifentanil after 0.5 mg kg⁻¹ IV bolus of propofol. The haemodynamic variables after seizure and the seizure duration were recorded. Time to return to spontaneous respiration, eye opening and achieving Aldrete score >9 were recorded.

Results

The electroencephalography seizure duration was significantly longer in groups R I (34.7±13 s) and R II (34.9±12) than in group P (24±7.5). Motor seizure duration was longer in groups R I (29.70±12.8) and R II (28.1±10) than in group P (21±7.3). The amount of total propofol was 121±21 mg in group P, 69.4±2 mg in group R I and 67±17 mg in group R II. Times to eye opening, following simple commands, and achieving Aldrete score >9 were significantly shorter in groups R I and R II than in group P.

Conclusion

ECT is a safe and effective treatment for patients with psychiatric disorders. Propofol-remifentanil anaesthesia prolongs the seizure duration and shortens the recovery time, suggesting that this combination may particularly be well suited for use in this patient group.

Effects of ketamine in electroconvulsive therapy for major depressive disorder: meta-analysis of randomised controlled trials

Background

The use of ketamine in electroconvulsive therapy (ECT) has been examined in the treatment of major depressive disorder (MDD); however, there has been no systematic review and meta-analysis of related randomised controlled trials (RCTs).

Aim

To examine the efficacy and safety of ketamine augmentation of ECT in MDD treatment.

Methods

Two reviewers searched Chinese (China National Knowledge Infrastructure and Wanfang) and English (PubMed, PsycINFO, Embase and Cochrane Library) databases from their inception to 23 July 2019. The included studies' bias risk was evaluated using the Cochrane risk of bias assessment tool. The primary outcome of this meta-analysis was improved depressive symptoms at day 1 after a single ECT treatment session. Data were pooled to calculate the standardised mean difference and risk ratio with their 95% CIs using RevMan V.5.3. We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to assess the whole quality of evidence.

Results

Four RCTs (n = 239) compared ketamine alone or ketamine plus propofol (n = 149) versus propofol alone (n = 90) in patients with MDD who underwent a single ECT session. Three RCTs were considered as unclear risk with respect to random sequence generation using the Cochrane risk of bias. Compared with propofol alone, ketamine alone and the combination of ketamine and propofol had greater efficacy in the treatment of depressive symptoms at days 1, 3 and 7 after a single ECT session. Moreover, compared with propofol alone, ketamine alone and the combination of ketamine and propofol were significantly associated with increased seizure duration and seizure energy index. Compared with propofol, ketamine alone was significantly associated with increased opening-eye time. Based on the GRADE approach, the evidence level of primary and secondary outcomes ranged from very low (26.7%, 4/15) to ‘low’ (73.3%, 11/15).

Conclusion

Compared with propofol, there were very low or low evidence levels showing that ketamine alone and the combination of ketamine and propofol appeared to rapidly improve depressive symptoms of patients with MDD undergoing a single ECT session. There is a need for high-quality RCTs.

Etomidate improves seizure adequacy during electroconvulsive therapy

The purpose of this study was to assess whether switching propofol to etomidate during an electroconvulsive therapy course improves seizure quality in convulsion-resistant patients. A retrospective study of paired cases included thirty-three patients. Seizure variables for each agent were assessed. A generalized linear mixed model (GLMM) for repeated measures was used for the analysis. Anesthesia with etomidate leads to greater seizure duration, improved seizure quality in the EEG register, and prevents further need for restimulation; although did not differ from propofol in the amount of energy delivered or in other automated parameters. These results suggest that this procedure appears to be an adequate strategy to improve seizure quality.

Anaesthesia for electroconvulsive therapy - new tricks for old drugs: a systematic review

OBJECTIVE

The objective of this review is to investigate existing literature in order to delineate whether the use of anaesthesia and timing of seizure induction in a new and optimised way may improve the efficacy of electroconvulsive therapy (ECT).

METHODS

PubMed/MEDLINE was searched for existing literature, last search on 24 June 2015. Relevant clinical studies on human subjects involving choice of anaesthetic, ventilation and bispectral index (BIS) monitoring in the ECT setting were considered. The references of relevant studies were likewise considered.

RESULTS

Propofol yields the shortest seizures, etomidate and ketamine the longest. Etomidate and ketamine+propofol 1 : 1 seems to yield the seizures with best quality. Seizure quality is improved when induction of ECT is delayed until the effect of the anaesthetic has waned - possibly monitored with BIS values. Manual hyperventilation with 100% O2 may increase the pO2/pCO2-ratio, which may be correlated with better seizure quality.

CONCLUSION

Etomidate or a 1 : 1 ketamine and propofol combination may be the best method to achieve general anaesthesia in the ECT setting. There is a need for large randomised prospective studies comparing the effect of methohexital, thiopental, propofol, ketamine, propofol+ketamine 1 : 1 and etomidate in the ECT treatment of major depressed patients. These studies should investigate safety and side effects, and most importantly have antidepressant efficacy and cognitive side effects as outcome measures instead of seizure quality.

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.

The Role of GABA Receptor Agonists in Anesthesia and Sedation

GABA (γ-aminobutyric acid) receptors, of which there are two types, are involved in inhibitory synapses within the central nervous system. The GABA_A receptor (GABAAR) has a central role in modern anesthesia and sedation practice, which is evident from the high proportion of agents that target the GABAAR. Many GABAAR agonists are used in anesthesia practice and sedation, including propofol, etomidate, methohexital, thiopental, isoflurane, sevoflurane, and desflurane. There are advantages and disadvantages to each GABAAR agonist currently in clinical use. With increasing knowledge regarding the pharmacology of GABAAR agonists, however, newer sedative agents have been developed which employ 'soft pharmacology', a term used to describe the pharmacology of agents whereby their chemical configuration allows rapid metabolism into inactive metabolites after the desired therapeutic effect(s) has occurred. These newer 'soft' GABAAR agonists may well approach ideal sedative agents, as they can offer well-controlled, titratable activity and ultrashort action. This review provides an overview of the role that GABAAR agonists currently play in sedation and anesthesia, in addition to discussing the future role of novel GABAAR agonists in anesthesia and sedation.

Intravenous theophylline is the most effective intervention to prolong EEG seizure duration in patients undergoing electroconvulsive therapy

BACKGROUND

Seizure duration in electroconvulsive therapy (ECT) is positively related with patients' outcome. This study sought to investigate the impact of anesthetic management on seizure duration, and the impact of selected drugs (theophylline, remifentanil, S-ketamine) on seizure duration.

METHODS

Retrospective analysis of all patients undergoing ECT at our institution from January 2011 to April 2012 was performed based on electronic medical chart and review of existing quality improvement data. Patient data (N = 78), including gender, age, height, weight, and administered drugs, energy levels, and electroencephalic seizure duration were analyzed. Statistical analysis was performed using a generalized linear model.

RESULTS

A total of 78 patients (male = 39, female = 39, age 51 ± 12 years) were included. Average number of session was 10 ± 6 (1-30). In our patient population, theophylline administration was the only parameter, which significantly prolonged seizure duration, whereas S-ketamine, remifentanil, thiopental, age, sex, session or energy level had no significant effect.

CONCLUSION

Theophylline can be a useful adjunct for patients with inadequate seizure duration. If there is a concomitant beneficial effect on patients' outcome needs to be investigated in further studies.

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.

Clinical Applicability of Monitoring the Time Interval Between Anesthesia and Electroconvulsive Therapy

The anesthetic-electroconvulsive therapy (ECT) time interval (time interval elapsed from the beginning of anesthesia injection to the beginning of ECT stimulus) has been reported to have an important impact on seizure quality outcomes, because it is an indirect measure of the anesthetic plasma concentration when the ECT electrical stimulus is administered. We report the importance of the routine monitoring of this time interval in clinical settings, as an additional measure to interpret seizure quality outcomes at each ECT session, to further assist on ECT dosing decisions during the treatment course.

Anaesthesia for electroconvulsive therapy: An overview with an update on its role in potentiating electroconvulsive therapy

Despite advances in pharmacotherapy, electroconvulsive therapy (ECT) remains a mainstay treatment option in psychiatry since its introduction in 1930s. It can be used primarily in severe illnesses when there is an urgent need for treatment or secondarily after failure or intolerance to pharmacotherapy. The 'unmodified' technique of ECT was practised initially, with a high incidence of musculoskeletal complications. Several modifications including general anaesthesia and muscle relaxation are used to increase the safety and patient acceptability of ECT. Various anaesthetic techniques including medications are considered to provide adequate therapeutic seizure, simultaneously controlling seizure-induced haemodynamic changes and side effects. A brief review of literature on choice of these anaesthetic techniques is discussed. This article is intended to reinforce the knowledge of clinicians, who may have limited exposure to ECT procedure. Importance is given to the recent updates on the role of induction agents in potentiating therapeutic response to ECT in psychiatric disorders.

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.

Use of Orally Disintegrating Olanzapine During Electroconvulsive Therapy for Prevention of Postictal Agitation

A major medical problem for patients undergoing electroconvulsive therapy (ECT) is the occurrence of postictal agitation (PIA). This phenomenon is associated with confusion and disorientation that can have severe clinical implications for the safety of the patient and health care professionals. Many different pharmacological strategies have been used to prevent PIA. We present data on 40 patients who suffered from PIA after a course of ECT and evaluate the prophylactic use of orally disintegrating olanzapine in the prevention of PIA in subsequent ECT treatments.

Which anesthetic agents for ambulatory electro-convulsive therapy?

PURPOSE OF REVIEW

There have been a considerable number of research articles published in the last 10 years outlining possible advances in the provision of electro-convulsive therapy (ECT) anaesthesia. This has resulted in a range of new drugs having been proposed as useful in the ECT setting. In particular, the use of adjuvant drugs that might improve outcomes to treatment has been investigated.

RECENT FINDINGS

There is a high level of interest in ketamine and remifentanil as agents that may alter response in ECT anaesthesia, by reducing cognitive effects, and minimizing the dose of induction agent. The numbers of patients involved in current trials have been small, and it is not possible to give a definitive answer as to the usefulness of these drugs at this stage.

SUMMARY

This review covers the major recent trials involving new and emerging treatments in ECT, and brings the reader up to date with state of knowledge of ECT anaesthesia and pharmacology.

The Anaesthetic-ECT Time Interval in Electroconvulsive Therapy Practice--Is It Time to Time?

BACKGROUND

Because most common intravenous anaesthetics used in ECT have anticonvulsant properties, their plasma-brain concentration at the time of seizure induction might affect seizure expression. The quality of ECT seizure expression has been repeatedly associated with efficacy outcomes. The time interval between the anaesthetic bolus injection and the ECT stimulus (anaesthetic-ECT time interval) will determine the anaesthetic plasma-brain concentration when the ECT stimulus is administered.

OBJECTIVE

The aim of this study was to examine the effect of the anaesthetic-ECT time interval on ECT seizure quality and duration.

METHODS

The anaesthetic-ECT time interval was recorded in 771 ECT sessions (84 patients). Right unilateral brief pulse ECT was applied. Anaesthesia given was propofol (1-2 mg/kg) and succinylcholine (0.5-1.0 mg/kg). Seizure quality indices (slow wave onset, amplitude, regularity, stereotypy and post-ictal suppression) and duration were rated through a structured rating scale by a single blinded trained rater. Linear Mixed Effects Models analysed the effect of the anaesthetic-ECT time interval on seizure quality indices, controlling for propofol dose (mg), ECT charge (mC), ECT session number, days between ECT, age (years), initial seizure threshold (mC) and concurrent medication.

RESULTS

Longer anaesthetic-ECT time intervals lead to significantly higher quality seizures (p < 0.001 for amplitude, regularity, stereotypy and post-ictal suppression).

CONCLUSIONS

These results suggest that the anaesthetic-ECT time interval is an important factor to consider in ECT practice. This time interval should be extended to as long as practically possible to facilitate the production of better quality seizures. Close collaboration between the anaesthetist and the psychiatrist is essential.

Post-electroconvulsive therapy recovery and reorientation time with methohexital and ketamine: a randomized, longitudinal, crossover design trial

OBJECTIVES

Methohexital, a barbiturate anesthetic commonly used for electroconvulsive therapy (ECT), possesses dose-dependent anticonvulsant properties, and its use can interfere with effective seizure therapy in patients with high seizure thresholds. Ketamine, an N-methyl-d-aspartate antagonist with epileptogenic properties not broadly used for ECT inductions, is a commonly used induction agent for general anesthesia. Recent studies suggest that the use of ketamine is effective in allowing successful ECT treatment in patients with high seizure thresholds without an increase in adverse effects. In this preliminary study, we directly compared the recovery and reorientation times of subjects receiving ketamine and methohexital for ECTs.

METHODS

Twenty patients were randomized in a crossover design to receive methohexital and ketamine for ECT inductions in alternating fashion in 6 trials. Primary outcome measures were recovery time (voluntary movement, respiratory effort, blood pressure, consciousness, and O2 saturation) and reorientation time. Secondary outcome measures were individual recovery variables, adverse effect occurrence, and seizure duration.

RESULTS

Overall recovery time was not significantly different between the 2 treatment arms (F(1, 17) = 0.72; P = 0.41). Reorientation time was faster in the methohexital arm (F(1, 17) = 9.23; P = 0.007).

CONCLUSION

Ketamine inductions resulted in higher number of adverse effects, higher subject dropout rates, and a longer reorientation time with respect to methohexital inductions. No significant difference in postanesthesia recovery time was found between the ketamine and methohexital arms. Intolerability to ketamine affected a significant proportion of subjects and suggests that ketamine should remain as an alternative or adjunctive agent for patients with high seizure thresholds.

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.

[Anesthesia for electroconvulsive therapy]

Electroconvulsive therapy is a well-established form of treatment for a broad spectrum of severe psychiatric disorders. The treatment, in which a generalized epileptic seizure is provoked by electrical stimulation of the brain, is performed with the patient under anesthesia and muscle relaxation. Therefore, sufficient knowledge of the physiological and pharmacological characteristics is an essential requirement for safe anesthesia. The following review is intended to provide some new aspects of the procedure and management of anesthesia.

Ketofol in electroconvulsive therapy anesthesia: two stones for one bird

PURPOSE

Propofol and ketamine have become progressively popular in electroconvulsive therapy (ECT) anesthesia, although propofol shortened seizure duration and ketamine might cause cardiotoxicity, psychotic episodes, and delayed recovery. Ketofol is a combination of ketamine and propofol, and the current study was designed to evaluate the effect of ketamine, propofol, and ketofol on hemodynamic profile, duration of seizure activity, and recovery times in patients undergoing ECT.

METHODS

Ninety patients (44 women, mean age 27.8 ± 7.2 years) in one ECT session were enrolled and randomized to the propofol, ketamine, or ketofol group. Hemodynamic profile duration of seizure activity and recovery times were recorded.

RESULTS

Motor seizure duration in the propofol group was significantly decreased compared to other groups (p < 0.001), whereas spontaneous breathing time in the ketamine group statistically increased compared to the propofol group (p = 0.001), and also eye-opening time (p < 0.001) and obeying-command time (p < 0.001) was significantly increased in the ketamine group compared to other groups. Heart rate (HR) at induction (ketamine 91.2 ± 13.6 vs. propofol 77 ± 13.4 and ketofol 79.9 ± 15.6; p < 0.013; p < 0.08, respectively) was statistically significantly increased in the ketamine group compared to other groups, and HR at the third minute (ketamine 92 ± 12.9 vs. propofol 79.4 ± 9.3 and ketofol 81.5 ± 14.2; p < 0.012, p < 0.048) was also statistically significantly increased in ketamine group compared to other groups.

CONCLUSION

The ketofol 1:1 mixture is associated with longer mean seizure time than propofol, and shorter mean recovery times than ketamine, with better hemodynamic stability, without any important side effects in ECT anesthesia.

Beat-to-beat hemodynamic monitoring during electroconvulsive therapy

OBJECTIVES

Rapid parasympathetic and sympathetic hemodynamic effects during electroconvulsive therapy (ECT) may pose vulnerable patients to significant risk for cardiovascular complications. Here, we evaluated the clinical feasibility of noninvasive beat-to-beat arterial blood pressure (BP) measurements in patients undergoing ECT.

METHODS

Beat-to-beat hemodynamic effects were measured with a noninvasive BP monitor in 24 individual patients undergoing ECT during general anesthesia. Heart rate, systolic (SBP), and diastolic BP (DBP) as well as cardiac output (CO) were measured continuously. A significant increase in pulse rate and/or BP was treated with intermittent administration of esmolol and ketanserin. Data are presented as mean ± SD.

RESULTS

The ECT stimulus induced a transient drop in BP and pulse rate, followed by a sharp rise in both parameters. The parasympathetic phase lasted 17 ± 9 seconds and was characterized by a drop in heart rate from 89 ± 15 to 42 ± 24 beats per minute, in SBP from 143 ± 22 to 91 ± 31 mm Hg, in DBP from 82 ± 13 to 54 ± 22 mm Hg, and in CO from 5.7 ± 2.3 to 1.4 ± 1.0 L/min, respectively. During the subsequent sympathetic phase, the heart rate increased to 125 ± 26 beats per minute, the SBP to 192 ± 33 mm Hg, the DBP to 113 ± 21 mm Hg, and the CO to 7.4 ± 4.3 L/min. The time interval between the lowest and highest SBP was 60 ± 48 seconds.

CONCLUSIONS

Noninvasive beat-to-beat BP measurements are feasible during ECT and may be used to guide rapid therapeutic interventions during ECT-induced hemodynamic effects.

General anesthetic actions on GABA(A) receptors

General anesthetic drugs interact with many receptors in the nervous system, but only a handful of these interactions are critical for producing anesthesia. Over the last 20 years, neuropharmacologists have revealed that one of the most important target sites for general anesthetics is the GABA_A receptor. In this review we will discuss what is known about anesthetic – GABA_A receptor interactions.

Randomized comparison of ultra-brief bifrontal and unilateral electroconvulsive therapy for major depression: clinical efficacy

BACKGROUND

It has been suggested that electroconvulsive therapy (ECT) with an ultra-brief pulse width in combination with a bilateral electrode placement has diminished antidepressive efficacy, as compared to unilateral ultra-brief pulse ECT.

OBJECTIVE

The antidepressive efficacy of bifrontal and right unilateral ultra-brief pulse (0.3 ms) ECT were compared.

METHOD

Eighty-one patients with a medication refractory depressive episode were treated with a course of bifrontal ultra-brief pulse ECT at 1.5 times seizure threshold or unilateral ultra-brief pulse ECT at 6 times seizure threshold by random assignment. The 17 item-Hamilton Rating Scale for Depression (HRSD), Beck Depression Inventory, Clinical Global Impression and Patient Global Impression were administered at baseline and repeated weekly during and 1 and 6 weeks after the course, by a blinded rater.

RESULTS

64/81 patients (79%) completed the study, half of which were treated with bifrontal ECT. At the end of the course, 78.1% of the BF group and 78.1% of the UL group responded, whereas, 34.38% (N=11) of the BF group and 43.75% (N=14) of the UL group achieved strict remission criteria (HRSD-score < or = 7). There were no significant differences between the patients given bifrontal ECT and those given unilateral ECT, although patients receiving unilateral ECT achieved response/remission-criteria after a smaller number of treatments.

LIMITATIONS

Relatively small number of subjects.

CONCLUSIONS

Using an ultra-brief pulse width, both BF and UL-ECT are efficacious, although patients receiving UL-ECT achieve response/remission-criteria after a smaller number of treatments.

TRIAL REGISTRY

http://www.controlled-trials.com/

REGISTRATION NUMBER

ISRCTN56570426.