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

An Observational Retrospective Study Investigating Changes in Seizure Adequacy Parameters of Electroconvulsive Therapy and Their Relationships to Clinical Outcome in Schizophrenia and Schizoaffective Disorder

The aim of the current study was to investigate a possible relationship between electroconvulsive therapy (ECT) seizure adequacy parameters and clinical outcome as well as differences between ECT responders and nonresponders in terms of ECT seizure parameters in patients diagnosed with schizophrenia and schizoaffective disorder. First and last ECT records data, sociodemographic variables, and baseline and post ECT Positive and Negative Syndrome Scale scores were obtained. Maximum sustained power was higher in last ECT in favor of responders while peak heart rate was higher in ECT nonresponders than responders in first ECT. Stimulus doses were higher in last ECT than in the first ECT in both groups. No predictor variable was observed among baseline ECT seizure parameters for clinical improvement. Study was insufficient to yield a precise finding pointing a relationship between electrophysiological seizure parameters and clinical outcome in schizophrenia and schizoaffective disorder.

The effects of hyperventilation on seizure length and cerebral oxygenation during electroconvulsive therapy

OBJECTIVE

Previous studies have reported that hyperventilation prolongs seizure length. However, there is no clear consensus in clinical guidelines on how to perform hyperventilation during Electroconvulsive Therapy (ECT). The present study aims to investigate the effects of hyperventilation on seizure length and cerebral oxygenation.

METHODS

Forty patients aged 18-65 and classified as ASA I-II, who would have their first ECT course were included in the study. Ethics committee approval was obtained and all patients' consent was taken. The consecutive patients were randomized into two groups as follows: group H (20 patients; target etCO2: 25-30 mmHg) and group N (20 patients; target etCO2 35-40 mmHg). All patients were ventilated with a facial mask for two minutes and later were ventilated by a laryngeal mask (LMA) for one minute. Vital signs, peripheric oxygen saturation (SpO2), and regional oxygen saturation (rSO2) were measured before general anesthesia induction, on the 3rd minute of ventilation with an LMA (LMA3), on the 1st minute postictal (PI1), on the 5th (PI5), and 10th (PI10) minutes. The motor seizure duration, Richmond sedation-agitation scale, and the time needed to reach Aldrete Score 9 were also recorded.

RESULTS

There was a significant difference between the groups when they were compared concerning seizure length and recovery time. However, when we compared the rSO2 values that were measured at different times in group H, the difference between the measurements was statistically significant. When rSO2 values in group H were compared in doubles, there were significant differences between measurements between the basal and LMA3, basal and PI1, and the basal and PI5. When Richmond agitation scores in both groups are compared, there were no significant differences between the groups.

CONCLUSION

This study found that seizure length was longer, and the recovery time was shorter in group H. There was a contribution of hyperventilation on cerebral oxygenation that was measured on the same person at different times, but cerebral oxygenation was not statistically different from patients that were normoventilated. More studies are required to form a consensus regarding how hyperventilation applies to ECT.

Hyperventilation and electroconvulsive therapy: A literature review

BACKGROUND

Hyperventilation has been proposed as an augmentation strategy in electroconvulsive therapy (ECT) in accordance with its proconvulsant effect.

OBJECTIVE

This study reviews the existing literature on the application of hyperventilation in ECT, its efficacy, and tolerance.

METHODS

A systematic search was performed in PubMed and EMBASE databases. Search terms ('electroconvulsive therapy' and 'hyperventilation', 'ventilation', 'hyperoxygenation', 'hyperoxia', 'hypocapnia') were used to retrieve works from 1966 to June 2016. Works that described hyperventilation manoeuvres in ECT settings and their clinical repercussion were included in the review.

RESULTS

A total of 17 observational and experimental studies were selected. An important heterogeneity in study designs, samples and ECT conditions, was detected. Findings support a positive influence of hyperventilation on seizure duration, which is the main study variable across different works. Effects of hyperventilation on seizure threshold and quality parameters have been less thoroughly studied. Systematic recording of clinical outcomes and adverse effects of hyperventilation is uncommon.

CONCLUSIONS

The literature suggests that hyperventilation may be an effective and safe technique to enhance ECT, but many aspects remain to be studied. Further investigations, especially controlled clinical trials, are necessary and should result in a specific and reliable hyperventilation protocol for ECT settings.

The Effects of Remifentanil on Hemodynamic Response Attenuation After Electroconvulsive Therapy Under Sevoflurane Anesthesia

PURPOSE

We evaluated the effects of a single loading dose of remifentanil (1 μg/kg) administered as an adjunct to sevoflurane, on the duration of seizure activity, recovery times, and hemodynamic profiles, during electroconvulsive therapy.

METHODS

The patients were randomly allocated to receive sevoflurane-saline (Group SS) or sevoflurane-remifentanil (Group SR). Sevoflurane (8%) was initiated for anesthesia induction in both groups until loss of consciousness was achieved. Remifentanil was then administered to Group SR via a 1-μg/kg intravenous bolus. Patients in Group SS received saline in the same manner. Mean arterial pressure (MAP) and heart rate (HR) were recorded before anesthetic induction (T1), at the loss of consciousness (T2), and at 0, 1, 3, and 10 minutes after the electrical stimuli were completed (T3, T4, T5, and T6, respectively).

RESULTS

Compared with the baseline values, HR increased significantly in Group SS at times T2 and T4 to T6 and decreased significantly in Group SR at time T2. When the groups were compared, we found that HR decreased significantly in Group SR at T2 and T4 to T6. Compared with baseline, MAP increased in Group SS between T3 and T6, and MAP decreased in Group SR at T2 and increased at T3 to T4. Mean arterial pressure decreased to a greater extent in Group SR than in Group SS during the T2 to T6 period. There were no group differences in seizure duration or recovery time.

CONCLUSIONS

The addition of 1-μg/kg remifentanil to anesthetic induction with sevoflurane attenuated the acute hemodynamic response to electroconvulsive therapy under sevoflurane anesthesia without adversely affecting the duration of seizure activity or the recovery profile.

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.

Does remifentanil improve ECT seizure quality?

Studies have reported that co-adjuvant remifentanil can enhance electroconvulsive therapy (ECT) seizure quality, putatively by allowing a reduction in the dosage of the main anaesthetic agents, as the latter have anticonvulsant properties. However, whether remifentanil also has direct effects on ECT seizure quality, and by implication, treatment efficacy, is unknown. This is the first study examining the effect of adjuvant remifentanil on ECT seizure quality when the dose of conventional anaesthesia remained unchanged. A total of 96 ECT sessions (from 36 patients) were retrospectively analysed. Subjects received ECT with and without remifentanil (1 µg/kg), while the dose of thiopentone (3-5 mg/kg) or propofol (1-2 mg/kg) was unchanged. Seizure quality indices (time to slow wave activity or TSLOW, amplitude, regularity, stereotypy, post-ictal suppression) and duration were assessed through a structured rating scale by a single trained blinded rater. Linear mixed-effects models with random subject effects analysed the effect of remifentanil on seizure parameters, controlling for other variables that can affect seizure quality or duration. Remifentanil was given in 47.9 % of the ECT sessions. Co-adjuvant remifentanil had no effects on any of the seizure quality parameters analysed [TSLOW (E = -0.21, p > 0.1), amplitude (E = 0.08, p > 0.5), regularity (E = -0.05, p > 0.5), stereotypy (E = -0.02, p > 0.5), suppression (E = -0.3, p > 0.05)] or on seizure duration (E = -0.25, p > 0.1). While adjuvant remifentanil may be a useful strategy for reducing anaesthetic dosage in ECT, present evidence suggests that remifentanil does not have intrinsic properties that enhance ECT seizures.

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.

Anaesthetic interventions for prevention of awareness during surgery

BACKGROUND

General anaesthesia is usually associated with unconsciousness. 'Awareness' is when patients have postoperative recall of events or experiences during surgery. 'Wakefulness' is when patients become conscious during surgery, but have no postoperative recollection of the period of consciousness.

OBJECTIVES

To evaluate the efficacy of two types of anaesthetic interventions in reducing clinically significant awareness:- anaesthetic drug regimens; and- intraoperative anaesthetic depth monitors.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, ISSUE 4 2016); PubMed from 1950 to April 2016; MEDLINE from 1950 to April 2016; and Embase from 1980 to April 2016. We contacted experts to identify additional studies. We performed a handsearch of the citations in the review. We did not search trial registries.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of either anaesthetic regimens or anaesthetic depth monitors. We excluded volunteer studies, studies of patients prior to skin incision, intensive care unit studies, and studies that only randomized different word presentations for memory tests (not anaesthetic interventions).Anaesthetic drug regimens included studies of induction or maintenance, or both. Anaesthetic depth monitors included the Bispectral Index monitor, M-Entropy, Narcotrend monitor, cerebral function monitor, cerebral state monitor, patient state index, and lower oesophageal contractility monitor. The use of anaesthetic depth monitors allows the titration of anaesthetic drugs to maintain unconsciousness.

DATA COLLECTION AND ANALYSIS

At least two authors independently scanned abstracts, extracted data from the studies, and evaluated studies for risk of bias. We made attempts to contact all authors for additional clarification. We performed meta-analysis statistics in packages of the R language.

MAIN RESULTS

We included 160 studies with 54,109 enrolled participants; 53,713 participants started the studies and 50,034 completed the studies or data analysis (or both). We could not use 115 RCTs in meta-analytic comparisons because they had zero awareness events. We did not merge 27 of the remaining 45 studies because they had excessive clinical and methodological heterogeneity. We pooled the remaining 18 eligible RCTs in meta-analysis. There are 10 studies awaiting classification which we will process when we update the review.The meta-analyses included 18 trials with 36,034 participants. In the analysis of anaesthetic depth monitoring (either Bispectral Index or M-entropy) versus standard clinical and electronic monitoring, there were nine trials with 34,744 participants. The overall event rate was 0.5%. The effect favoured neither anaesthetic depth monitoring nor standard clinical and electronic monitoring, with little precision in the odds ratio (OR) estimate (OR 0.98, 95% confidence interval (CI) 0.59 to 1.62).In a five-study subset of Bispectral Index monitoring versus standard clinical and electronic monitoring, with 34,181 participants, 503 participants gave awareness reports to a blinded, expert panel who adjudicated or judged the outcome for each patient after reviewing the questionnaires: no awareness, possible awareness, or definite awareness. Experts judged 351 patient awareness reports to have no awareness, 87 to have possible awareness, and 65 to have definite awareness. The effect size favoured neither Bispectral Index monitoring nor standard clinical and electronic monitoring, with little precision in the OR estimate for the combination of definite and possible awareness (OR 0.96, 95% CI 0.35 to 2.65). The effect size favoured Bispectral Index monitoring for definite awareness, but with little precision in the OR estimate (OR 0.60, 95% CI 0.13 to 2.75).We performed three smaller meta-analyses of anaesthetic drugs. There were nine studies with 1290 participants. Wakefulness was reduced by ketamine and etomidate compared to thiopental. Wakefulness was more frequent than awareness. Benzodiazepines reduces awareness compared to thiopental, ketamine, and placebo., Also, higher doses of inhaled anaesthetics versus lower doses reduced the risk of awareness.We graded the quality of the evidence as low or very low in the 'Summary of findings' tables for the five comparisons.Most of the secondary outcomes in this review were not reported in the included RCTs.

AUTHORS' CONCLUSIONS

Anaesthetic depth monitors may have similar effects to standard clinical and electrical monitoring on the risk of awareness during surgery. In older studies comparing anaesthetics in a smaller portion of the patient sample, wakefulness occurred more frequently than awareness. Use of etomidate and ketamine lowered the risk of wakefulness compared to thiopental. Benzodiazepines compared to thiopental and ketamine, or higher doses of inhaled anaesthetics versus lower doses, reduced the risk of awareness.

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.

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

BACKGROUND/AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Ketofol (Mixture of Ketamine and Propofol) Administration in Electroconvulsive Therapy

The aim of this study was to evaluate the effect of a ketamine:propofol combination (‘ketofol’) for electroconvulsive therapy on seizure activity, haemodynamic response and recovery parameters, and to compare with these with the effects of propofol alone. Twenty-four patients underwent a total of 144 electro-convulsive therapy sessions, allocated in this prospective, double-blind, crossover study. Patients were randomly assigned to receive 1 mg/kg ketofol (0.5 mg/kg propofol plus 0.5 mg/kg ketamine) or 1 mg/kg propofol 1% for anaesthesia induction. Seizure duration and quality, haemodynamic data, recovery parameters and side-effects were recorded and analysed between groups. Both motor and electroencephalography seizure durations in the ketofol group (29±17 and 41±17 seconds, respectively) were similar to that in the propofol group (28±13 and 38±16 seconds, respectively). Postictal suppression index was higher in the ketofol group (89.63±7.88) than in the propofol group (79.74±14.6) (P P <0.05). There were no untoward psychological reactions following ketofol. Although no superiority to propofol in terms of seizure duration, haemodynamic or recovery parameters was found, the ketofol mixture selected in our study provided better seizure quality than propofol. We conclude that ketofol can be an alternative strategy to enhance the seizure quality and clinical efficiency of electroconvulsive therapy.

Augmentation strategies in electroconvulsive therapy

Electroconvulsive therapy (ECT) is a highly effective treatment, but strategies to enhance therapeutic outcomes are occasionally needed. This review examines the evidence for approaches used for enhancing seizure production: hyperventilation, pretreatment with xanthines, and use of remifentanil or ketamine in ECT anesthesia. Hyperventilation may be a useful strategy to enhance seizure production, but its effects on ECT outcomes have not been systematically studied and require further research. Pretreatment with caffeine, theophylline or aminophylline (xanthines) prolongs the duration of ECT seizures but has not been clearly shown in controlled trials to increase efficacy. Caution is also warranted because their use may be associated with significant adverse effects. There are case reports of the usefulness of remifentanil in assisting seizure induction by reducing the dose of barbiturate anesthetic required, but there are no controlled data on whether it independently enhances efficacy outcomes. Preliminary evidence suggests that ketamine and ECT may have synergistic antidepressant effects, although this needs to be further examined in randomized controlled trials.