A comparison of propofol and thiopentone use in electroconvulsive therapy: cognitive and efficacy effects

Anesthetic Influence on Electroconvulsive Therapy: A Comprehensive Review

The prevalence of severe mental disorders has been rising annually. Electroconvulsive therapy (ECT) is considered a valuable treatment option in psychiatry for conditions such as schizophrenia and medication-resistant depression, especially when other treatments have proven insufficient. ECT rapidly improves patients' mood, alleviates symptoms, and demonstrates significant therapeutic effects. Currently, the form of ECT used in clinical practice is modified electroconvulsive therapy (mECT), which is administered under general anesthesia. Accumulative evidence has confirmed that different anesthetic drugs, anesthetic-ECT time interval, anesthetic depth, and airway management can impact the outcomes of ECT. Therefore, this review aims to summarize the current impact of anesthesia factors on ECT, providing reference for clinical anesthesia during ECT procedures.

Comparative efficacy and tolerability of different anesthetics in electroconvulsive therapy for major depressive disorder: A systematic review and network meta-analysis

Electroconvulsive therapy (ECT) is one of the most effective treatments for major depressive disorder. Modern ECT is conducted with anesthesia, however, the optimal anesthetic agent for ECT is yet to be understood. This study is aimed to compare the effects of different anesthetic agents on antidepressant efficacy and tolerability in depressed individuals undergoing ECT. We searched MEDLINE, EMBASE, the CENTRAL and PsycINFO for randomized controlled trials from database inception until Nov 13, 2022 (PROSPERO: CRD42022375407). Global and local inconsistencies, heterogeneity and publication bias were assessed. Rankings were calculated with the surface under the cumulative ranking curve. A total of 33 studies involving 1898 patients were enrolled. Remission rates were higher for ketamine anesthesia as compared to adjunctive ketamine and propofol. In terms of ranking, ketamine was found to be first in terms of response/remission rates and depressive scores after the 1st, 3rd and 6th ECT and at the end of ECT session, while a higher incidence of adverse events was also observed. No significant advantage of any anesthetic was revealed for the cognitive function after ECT. In summary, based on current evidence, no specific anesthetic is recommended for ECT anesthesia. However, despite more side effects, ketamine monoanesthesia seems to reveal a potential benefit in improving antidepressant efficacy of ECT, and further studies are needed to investigate the relationship between anesthetic agents and the therapeutic effect of ECT.

The concentration of MMP-9 and the effects of intravenous anaesthetics on the efficacy of electroconvulsive therapy in patients with drug-resistant depression

Introduction: This study attempts to assess the concentration of intracellular matrix metalloproteinase (MMP-9) before and after the treatment of depressive episodes with ECT therapy and also to correlate the concentration of this enzyme with the use of commonly used general anaesthetics.

Materials and methods: The study group comprised of 37 patients hospitalized in the Department of Adult Psychiatry in Poznan, with a diagnosis of episodes of drug-resistant depression during the course of bipolar and unipolar affective disorders, and who were being treated using electroconvulsive therapy. For the purpose of inducing anaesthesia during the procedure propofol was used in 10 cases, thiopental in 9 cases. Propofol was alternated with ketamine in a further 10 cases and thiopental was alternated with ketamine in another 9 cases. In order to assess the intensity of depression symptoms, the 17 point Hamilton depression scale was used, immediately before commencing ECT therapy, and one day after its completion. The serum concentration of MMP-9 was determined before and after the series of ECT treatments. In order to assess the serum concentration of MMP-9, an ELISA immunoenzymatic method was applied.

Results: In this study, a significant reduction of MMP-9 concentration was noted after therapy, relative to the starting concentration, in the serum of patients suffering from depressive episodes resulting from either unipolar or bipolar affective disorders. These results correlated with improved psychiatric state, as assessed by the Hamilton scale. A significantly lower MMP-9 concentration was noted in the serum of patients given alternating thiopental and ketamine anaesthesia.

Conclusions: This study suggests the importance of the enzyme as a biological marker for the effective treatment of depression. Furthermore, the choice of general anaesthetic applied during ECT also plays a role.

Frequency and Duration of Course of ECT Sessions: An Appraisal of Recent Evidence

AIMS AND METHOD

This paper aims to review the recent literature regarding factors influencing the frequency and number of sessions during a course of electroconvulsive therapy (ECT) for different psychiatric disorders. We systematically reviewed English-language papers of clinical trials of ECT published since the year 2000 in terms of frequency and number of sessions of ECT.

RESULTS

None of the 30 studies meeting our inclusion criteria were specifically designed to study frequency or number of sessions of ECT. A preliminary inference may be drawn regarding the number of sessions from the information available in these papers. For depression, patients receiving brief-pulse ECT needed fewer sessions than those receiving ultra-brief ECT when these were delivered at 8-times the threshold with unilateral electrode placement or at 2.5-times the threshold with bilateral placement. For schizophrenia, those receiving bifrontal ECT and ECT at 4-times the threshold-level stimulus needed fewer sessions than those receiving bitemporal ECT and 2-times the threshold-level stimulus, respectively. There were no clinical trials of the frequency of ECT sessions.

CLINICAL IMPLICATIONS

As there is a dearth of studies specifically examining frequency and number of ECT sessions, broad recommendations from professional bodies should continue to guide practice.

The use of ketamine in ECT anaesthesia: A systematic review and critical commentary on efficacy, cognitive, safety and seizure outcomes

OBJECTIVES

This review will discuss ECT efficacy and cognitive outcomes when using ketamine as an ECT anaesthetic compared to other anaesthetics, taking into account important moderator variables that have often not been considered to date. It will also include information on safety and other ECT outcomes (seizure threshold and quality).

METHODS

A systematic search through MEDLINE, PubMed, PsychINFO, Cochrane Databases and reference lists from retrieved articles was performed. Search terms were: "ketamine" and "Electroconvulsive Therapy", from 1995 to September 2016. Meta-analyses, randomised controlled trials, open-label and retrospective studies published in English of depressed samples receiving ECT with ketamine anaesthesia were included (n = 24).

RESULTS

Studies were heterogeneous in the clinical populations included and ECT treatment and anaesthetic methods. Frequently, studies did not report on ECT factors (i.e., pulse-width, treatment schedule). Findings regarding efficacy were mixed. Tolerance from repeated use may explain why several studies found that ketamine enhanced efficacy early in the ECT course but not at the end. The majority of studies did not comprehensively examine cognition and adverse effects were not systematically studied. Only a minority of the studies reported on seizure threshold and expression.

CONCLUSIONS

The routine use of ketamine anaesthesia for ECT in clinical settings cannot yet be recommended based on published data. Larger randomised controlled trials, taking into account moderator variables, specifically reporting on ECT parameters and systematically assessing outcomes are encouraged.

Retrospective comparison of effectiveness of right unilateral ultra-brief pulse with brief pulse ECT in older adults (over 65) with depression

BACKGROUND

To compare response, remission and switch (to other pulse width and/or electrode placement) rates and number of treatments between groups receiving right unilateral ultra-brief (RUL-UB), Bitemporal brief (BT), Bifrontal Brief (BF) and Right unilateral brief (RUL-B).

METHOD

Data was collected from case notes in three centers. There were 133 in total, grouped as RUL-UB (50), BT (43), BF (23), RUL-B (17). Two of the three centers had a preferred electrode placement and pulse width.

RESULTS

Apart from age, the groups did not differ significantly on sex distribution, proportion of bipolar depression and psychotic symptoms. 56% of patients in RUL-UB switched compared to 12.5% in RUL-B, 4.9% in BT and none in BF (p value < 0.0001). When we considered patients who switched as treatment failures, remission rates were significantly different (p value < 0.0001) 40% in RUL-UB, 81.3% in RUL-B, 73.9% in BF and 78.0% in BT. Mean number of treatments in each group was significantly different (p value < 0.0001); 12.02 in RUL-UB, 10.2 in RUL-B, 7 in BF and 7.5 in BT. Post-hoc analysis indicated that RUL-UB differed significantly from BT and BF. Final response and remission rates including patients who switched were 98% and 82% in RUL-UB, 100% and 93.8% in RUL-B, 100% and 73.9% in BF and 97.7% and 83.7% in BT.

CONCLUSION

Majority commencing RUL-UB switched and received 4-5 more treatments compared to bilateral placements. RUL-UB ECT appears less effective and might not be appropriate as first line for all older adults as some patients at higher anaesthetic risk would benefit from having reduced number of treatments.

A Bayesian framework systematic review and meta-analysis of anesthetic agents effectiveness/tolerability profile in electroconvulsive therapy for major depression

The aim of this study was to assess the efficacy and tolerability/acceptability of 6 anesthetic agents in ECT for depressive disorders. We systematically reviewed 14 double-blind randomized controlled trials (610 participants). Efficacy was measured by the mean scores on validated depression scales at 6 ECT (or the nearest score if not available), number of responders at the end of treatment and seizure duration. The acceptability was measured by the proportion of patients who dropped out of the allocated treatment, and the tolerability by the number of serious adverse events and post-treatment cognition assessment. After excluding the trials responsible for heterogeneity, depression scores of patients who were administered methohexital were found to be significantly more improved than those who received propofol (p = 0.001). On the contrary, those who were administered propofol had lower depression scores than those with thiopental at the end of treatment (p = 0.002). Compared to propofol, methohexital was found to be significantly associated with higher seizure duration (p = 0.018). No difference was found for the acceptability profile (all p > 0.05). In summary, ketamine and methohexital may be preferred to propofol or thiopental in regard of effectiveness in depression scores and increased seizure duration. Further studies are warranted to compare ketamine and methohexital.

Seizure Duration and Hemodynamic State During Electroconvulsive Therapy: Sodium Thiopental Versus Propofol

Introduction:

General anesthesia is required for Electroconvulsive Therapy (ECT) and it is usually provided by a hypnotic agent. The seizure duration is important for the treatment, and it is usually accompanied by severe hemodynamic changes. The aim of this study was to compare the effects of sodium thiopental versus Propofol on seizure duration and hemodynamic variables during ECT.

Methods:

A number of 100 patient-sessions of ECT were included in this randomized clinical trial. The initial hemodynamic state of each patient was recorded. Anesthesia was induced by Sodium thiopental in the 1^st group and with Propofol in 2^nd group. All the patients received the muscle relaxant succinylcholine. The hemodynamic variables after seizure and seizure duration were recorded. The data were analyzed through SPSS 20 and independent t-test. P<0.05 was considered significant.

Results:

The mean duration of seizure in the sodium thiopental group was significantly longer than the Propofol group (40.3±16.6 sec versus 32±11.3 sec) (P=0.001). There was no statistically significant difference between the mean energy level applied in the two groups (20.5±3.81 joules in the sodium thiopental versus 20.2±3.49 joules in the Propofol group). The mean systolic and diastolic blood pressure at all times after seizure and mean heart rate at 3 and 5 minutes after seizure were significantly lower in Propofol than sodium thiopental groups.

Discussion and Conclusion:

Propofol provides a more stable hemodynamic state for the ECT procedures, and its use is highly preferred over sodium thiopental in patients with cardiovascular disease.

The role of APOE-ɛ4 and beta amyloid in the differential rate of recovery from ECT: a review

Individual biological differences may contribute to the variability of outcomes, including cognitive effects, observed following electroconvulsive treatment (ECT). A narrative review of the research literature on carriage of the apolipoprotein E ɛ4 allele (APOE-ɛ4) and the protein biomarker beta amyloid (Aβ) with ECT cognitive outcome was undertaken. ECT induces repeated brain seizures and there is debate as to whether this causes brain injury and long-term cognitive disruption. The majority of ECT is administered to the elderly (over age 65 years) with drug-resistant depression. Depression in the elderly may be a symptom of the prodromal stage of Alzheimer's disease (AD). Carriage of the APOE-ɛ4 allele and raised cerebral Aβ are consistently implicated in AD, but inconsistently implicated in brain injury (and related syndromes) recovery rates. A paucity of brain-related recovery, genetic and biomarker research in ECT responses in the elderly was found: three studies have examined the effect of APOE-ɛ4 allele carriage on cognition in the depressed elderly receiving ECT, and two have examined Aβ changes after ECT, with contradictory findings. Cognitive changes in all studies of ECT effects were measured by a variety of psychological tests, making comparisons of such changes between studies problematic. Further, psychological test data-validity measures were not routinely administered, counter to current testing recommendations. The methodological issues of the currently available literature as well as the need for well-designed, hypothesis driven, longitudinal studies are discussed.

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.

Comparing ECT data of two different inpatient clinics: propofol or thiopental?

OBJECTIVE

This study compares the data of (modified) electroconvulsive theraphy (ECT) applications from two different inpatient clinics in Turkey: Kocaeli Derince Training and Research Hospital (Clinic-I) and Kocaeli University (Clinic-II).

METHODS

Recorded files of patients from the two clinics were compared in terms of ECT indications, number and duration of seizures, and anesthetic agents used (propofol vs. thiopental). ECT applications occurring between January 2011 and January 2013 were included in the study.

RESULTS

A total of 86 patients (9.5% of the inpatients) received ECT in Clinic-I and 103 patients (21.1% of the inpatients) in Clinic-II during the period studied. The yearly ECT rate (treated person rate per 10,000 per year) was 0.59/10,000 for Kocaeli (Turkey) as a whole. The overall number of ECT applications was 539 in Clinic-I and 999 in Clinic-II, and the average number of ECT sessions for each patient was 6.4 ± 2.33 in Clinic-I and 9.69 ± 4.66 in Clinic-II. The majority of indications were depressive disorders and insufficient response to medicine. Patients in the clinic which utilized thiopental as the anesthetic agent experienced more cardiovascular and respiratory side effects than the one which used propofol. The number of ECT sessions required was greater for patients with schizoaffective disorder than for others.

CONCLUSIONS

The administration of ECT was considered to be a reliable method of treatment in these clinics. With respect to specific anesthetic agents, propofol was found to have less hemodynamic side effects and shorter seizure durations than thiopental.

Propofol and thiopental as anesthetic agents in electroconvulsive therapy: a retrospective study in major depression

OBJECTIVE

To determine the influence of propofol and thiopental as anesthetics in electroconvulsive therapy (ECT), as regards, seizure duration, electrical charge, clinical efficacy, cardiovascular profile, and presence of adverse cognitive effects.

METHODS

A retrospective design including 127 patients who received bilateral ECT for the treatment of a major depressive episode.

RESULTS

The mean seizure duration in the propofol group was significantly shorter than in the thiopental group (21.23±6.09 versus 28.24±6.6 7s, P<.001). The mean stimulus charge was 348.22 mC in the propofol group, and 238 mC in the thiopental group (P<.001). Propofol was associated with a lower increase in blood pressure. There were no differences between groups in treatment response or presence of adverse effects.

CONCLUSIONS

The anesthetic agent used in ECT might determine differences in parameters such as seizure duration or electrical charge. However, this does not seem to be translated into differences in clinical efficacy or the pattern of adverse effects observed.

Objective cognitive performance associated with electroconvulsive therapy for depression: a systematic review and meta-analysis

BACKGROUND

Electroconvulsive therapy (ECT) is the most acutely effective treatment for depression, but is limited by cognitive side effects. However, research on their persistence, severity, and pattern is inconsistent. We aimed to quantify ECT-associated cognitive changes, specify their pattern, and determine progression.

METHODS

MEDLINE, EMBASE, PsycArticles, PsychINFO, PsychLIT, and reference lists were systematically searched through January 2009. We included all independent, within-subjects design studies of depressed patients receiving ECT where cognition was assessed using standardized tests. Main outcome was change in performance after ECT relative to pretreatment scores with respect to delay between finishing ECT and cognitive testing. We explored potential moderators' influence, e.g., electrode placement, stimulus waveform.

RESULTS

Twenty-four cognitive variables (84 studies, 2981 patients) were meta-analyzed. No standardized retrograde amnesia tests were identified. Significant decreases in cognitive performance were observed 0 to 3 days after ECT in 72% of variables: effect sizes (ES) ranging from -1.10 (95% confidence interval [CI], -1.53 to -.67) to -.21 (95% CI, -.40 to .01). Four to 15 days post-ECT, all but one CI included zero or showed positive ES. No negative ES were observed after 15 days, with 57% of variables showing positive ES, ranging from .35 (95% CI, .07-.63) to .75 (95% CI, .43-1.08). Moderators did not influence cognitive outcomes after 3 days post-ECT.

CONCLUSIONS

Cognitive abnormalities associated with ECT are mainly limited to the first 3 days posttreatment. Pretreatment functioning levels are subsequently recovered. After 15 days, processing speed, working memory, anterograde memory, and some aspects of executive function improve beyond baseline levels.

Effects of electroconvulsive therapy and propofol on spatial memory and glutamatergic system in hippocampus of depressed rats

OBJECTIVES

This animal study tested the spatial learning memory of "depressed" rats undergoing electroconvulsive therapy (ECT) or ECT combined with propofol and aimed to reveal the glutamatergic mechanisms in the hippocampus.

METHODS

Sixty Sprague-Dawley rats were randomly divided into 5 groups (n = 12 rats per group): control group, depression group, propofol group, ECT group, and propofol + ECT group. Rats were stressed repeatedly for 21 days to establish depression model. After the model was set up, rats of the propofol group were administrated with propofol (100 mg/kg). Rats of ECT group were administered ECT once on alternate days for 2 weeks. ECT + propofol group rats were given ECT after anesthesia with propofol (100 mg/kg). Spatial memory was assessed by Morris water maze. Glutamate content in hippocampus was measured by chromatometry. N-methyl d-aspartate (NMDA)-NR2B expression was detected by immunohistochemistry.

RESULTS

After treatment, the behavior level of rats in ECT group and ECT + propofol group was higher than that in depression group, and there was no significance between ECT group and ECT + propofol group. The evasive latency of rats detected by Morris water maze got shorter and shorter from the first day to fourth day. The evasive latency in ECT group was longer than that in ECT + propofol group and depression group, and the evasive latency in ECT + propofol group was shorter than that in depression group. Glutamate contents in hippocampus of rats in depression group and propofol group were higher than those in other groups, and glutamate content in ECT group was lower than that in other groups. The content in ECT + propofol group was lower than that in depression group, but higher than that in ECT group. N-methyl d-aspartate-NR2B expression in hippocampus of rats in depression group was lower than that in control group, but the expressions in ECT group and ECT + propofol group were higher than that in control group, and the expression in ECT + propofol group was lower than that in ECT group.

CONCLUSIONS

The glutamate content in hippocampus of depressed rats heightens, and the NMDA-NR2B expression down-regulated, which may cause "depression" symptoms and learning memory impairment. After ECT, the glutamate contents decreased, and NMDA-NR2B expression up-regulated, the depression symptoms improved, and the spatial memory worsened simultaneously. However, propofol inhibited the excessive decrease of glutamate and excessive up-regulation of NMDA-NR2B caused by ECT, and both the depression symptoms and the spatial memory of depressed rats improved.

Therapeutic options for treatment-resistant depression

Treatment-resistant depression (TRD) presents major challenges for both patients and clinicians. There is no universally accepted definition of TRD, but results from the US National Institute of Mental Health's (NIMH) STAR*D (Sequenced Treatment Alternatives to Relieve Depression) programme indicate that after the failure of two treatment trials, the chances of remission decrease significantly. Several pharmacological and nonpharmacological treatments for TRD may be considered when optimized (adequate dose and duration) therapy has not produced a successful outcome and a patient is classified as resistant to treatment. Nonpharmacological strategies include psychotherapy (often in conjunction with pharmacotherapy), electroconvulsive therapy and vagus nerve stimulation. The US FDA recently approved vagus nerve stimulation as adjunctive therapy (after four prior treatment failures); however, its benefits are seen only after prolonged (up to 1 year) use. Other nonpharmacological options, such as repetitive transcranial stimulation, deep brain stimulation or psychosurgery, remain experimental and are not widely available. Pharmacological treatments of TRD can be grouped in two main categories: 'switching' or 'combining'. In the first, treatment is switched within and between classes of compounds. The benefits of switching include avoidance of polypharmacy, a narrower range of treatment-emergent adverse events and lower costs. An inherent disadvantage of any switching strategy is that partial treatment responses resulting from the initial treatment might be lost by its discontinuation in favour of another medication trial. Monotherapy switches have also been shown to have limited effectiveness in achieving remission. The advantage of combination strategies is the potential to build upon achieved improvements; they are generally recommended if partial response was achieved with the current treatment trial. Various non-antidepressant augmenting agents, such as lithium and thyroid hormones, are well studied, although not commonly used. There is also evidence of efficacy and increasing use of atypical antipsychotics in combination with antidepressants, for example, olanzapine in combination with fluoxetine (OFC) or augmentation with aripiprazole. The disadvantages of a combination strategy include multiple medications, a broader range of treatment-emergent adverse events and higher costs. Several experimental pharmaceutical treatment alternatives for TRD are also being explored in combination with antidepressants or as monotherapy. These less studied alternative compounds include pindolol, inositol, CNS stimulants, hormones, herbal supplements, omega-3 fatty acids, S-adenosyl-L-methionine, folic acid, lamotrigine, modafinil, riluzole and topiramate. In summary, despite an increasing variety of choices for the treatment of TRD, this condition remains universally undefined and represents an area of unmet medical need. There are few known approved pharmacological agents for TRD (aripiprazole and OFC) and overall outcomes remain poor. This might be an indication that depression itself is a heterogeneous condition with a great diversity of pathologies, highlighting the need for careful evaluation of individuals with depressive symptoms who are unresponsive to treatment. Clearly, more research is needed to provide clinicians with better guidance in making those treatment decisions--especially in light of accumulating evidence that the longer patients are unsuccessfully treated, the worse their long-term prognosis tends to be.

Comparison of propofol and thiopental as anesthetic agents for electroconvulsive therapy: a randomized, blinded comparison of seizure duration, stimulus charge, clinical effect, and cognitive side effects

OBJECTIVES

To compare propofol and thiopental as anesthetic agents for electroconvulsive therapy (ECT) with respect to seizure duration, stimulus charge, clinical effect, and cognitive side effects.

METHODS

Randomized, blinded study of 62 depressed patients treated with bilateral ECT. Algorithm-based charge dosing was used.

RESULTS

The mean seizure duration of the patients in the thiopental group was 36.3 seconds versus 25.7 seconds in the propofol group (P = 0.001). The charge per treatment was 79.5 mC in the thiopental group versus 109.8 mC in the propofol group (P = 0.026). Sixteen patients in the propofol group (52%) reached the highest electrical dose versus 8 patients (26%) in the thiopental group (P = 0.014). No difference in response to treatment or number of treatments was observed. The mean score on Mini-Mental State Examination (MMSE) was 28.9 in the thiopental group versus 26.8 in the propofol group (P = 0.014). However, age distribution of patients completing the study differed between the groups.

CONCLUSIONS

Propofol significantly decreases seizure duration without significant difference in the clinical outcome. Using the employed treatment algorithm, patients anesthetised with propofol received higher electrical charge. Mini-Mental State Examination scores suggest that this results in more severe cognitive side effects. Results, however, might be confounded by the differences in age distribution in the groups.

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.

Cognitive side effects of brief pulse electroconvulsive therapy: a review

Cognitive impairment remains a common side effect of brief pulse electroconvulsive therapy (ECT), and its minimization has been the motivation for many different treatment modifications over the decades. The level of impairment has been shown to vary according to different technical parameters of ECT including, but not limited to, electrode placement, dosage, and waveform, as well as patient factors, such as age and premorbid intellect. Most past research has focused the assessment on memory impairments associated with ECT. Specifically, ECT can result in both anterograde and retrograde memory impairments. However, the study of non-memory cognitive functions after ECT has been relatively neglected. Furthermore, although considerable recovery has been observed within weeks of treatment completion, data are lacking in the longer term. The following article presents an overview of what is currently known about the pattern and recovery of cognitive side effects of ECT. Controversies within the literature and areas requiring further research are highlighted.