Etomidate anesthesia increases seizure duration during ECT. A retrospective study

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.

Comparison of effect of etomidate with propofol on hemodynamics during modified electroconvulsive therapy

Background and Aims:

Studies comparing the effect of propofol and etomidate on hemodynamic parameters during electroconvulsive therapy (ECT) have shown ambiguous results. Although some studies observed a larger increase in blood pressure and heart rate during the use of etomidate than propofol in ECT, whereas some studies have shown no difference in hemodynamic parameters with the use of etomidate or propofol. Most of the studies done to compare the hemodynamic effects of etomidate and propofol were limited by small sample size or retrospective in nature. Therefore, we conducted a prospective randomized trial to compare the effects of etomidate and propofol on hemodynamics during ECT.

Material and Methods:

A prospective randomized crossover study was conducted on 30 patients with American Society of Anesthesiologist physical status I and II, between age 18 and 65 years, suffering from a mental disorder as per International Classification of Diseases-10 and requiring bilateral ECT as per clinical decision of consultant psychiatrist. They were randomized to receive both the drugs for their successive ECT sessions and were subjected to evaluation after clubbing together the ECT sessions of propofol or etomidate as anesthetic agent.

Results:

Duration of motor seizures was significantly more in patients receiving etomidate, whereas patients receiving propofol had more stable hemodynamics.

Conclusion:

Though propofol maintains stable hemodynamics during MECT, yet clinical applicability of etomidate outstrips it by a reasonable margin due to its better effect on seizure parameters.

Anaesthesia for electroconvulsive therapy: a role for etomidate

Aims and Method

Three cases are described to illustrate the elective use of etomidate in electroconvulsive therapy (ECT) anaesthesia.

Results

Use of etomidate is described in an individual who was treated with an electrical stimulus at the maximum level for the ECT machine in use; in a person who had severe side-effects with an alternative induction agent; and in a person with severe cardiac disease.

Clinical Implications

The anaesthetic drug should be tailored to the individual needs of the person being treated with ECT. Clinics should involve local anaesthetic departments in reviewing their anaesthetic practice.

Dexmedetomidine Combined With Intravenous Anesthetics in Electroconvulsive Therapy: A Meta-analysis and Systematic Review

OBJECTIVE

The aim of this study was to investigate how the combined use of dexmedetomidine with intravenous anesthetics influences seizure duration and circulatory dynamics in electroconvulsive therapy (ECT).

METHODS

A literature search was performed to identify studies that evaluated the effect of dexmedetomidine on motor- or electroencephalogram (EEG)-based seizure durations and maximum mean arterial pressure (MAP) and heart rate (HR) after ECT. Moreover, recovery time and post-ECT agitation were evaluated.

RESULTS

Six studies enrolling 166 patients in 706 ECT sessions were included. There was no significant difference in motor or EEG seizure duration between dexmedetomidine and nondexmedetomidine groups [motor: 6 studies; mean difference (MD), 1.62; 95% confidence interval (CI), -2.24 to 5.49; P = 0.41; EEG: 3 studies; MD, 2.34; 95% CI, -6.03 to 10.71; P = 0.58]. Both maximum MAP and HR after ECT were significantly reduced in the dexmedetomidine group (MAP: 6 studies; MD, -4.83; 95% CI, -8.43 to -1.22; P = 0.009; HR: 6 studies; MD, -6.68; 95% CI, -10.74 to -2.62; P = 0.001). Moreover, the addition of dexmedetomidine did not significantly prolong recovery time when the reduced-dose propofol was used (4 studies; MD, 63.27; 95% CI, -15.41 to 141.96; P = 0.12).

CONCLUSIONS

The use of dexmedetomidine in ECT did not interfere with motor and EEG seizure durations but could reduce maximum MAP and HR after ECT. Besides, the addition of dexmedetomidine in ECT did not prolong recovery time when reduced-dose propofol was used. It might be worthwhile for patients to receive dexmedetomidine before the induction of anesthesia in ECT.

Anaesthesia and epilepsy

Epilepsy is the most common serious neurological disorder, with a prevalence of 0.5-1% of the population. While the traditional antiepileptic drugs (AEDs) still play a significant role in treatment of seizures, there has been an influx of newer agents over the last 20 yr, which are now in common usage. Anaesthetists are frequently faced with patients with epilepsy undergoing emergency or elective surgery and patients suffering seizures and status epilepticus in the intensive care unit (ICU). This review examines perioperative epilepsy management, the mode of action of AEDs and their interaction with anaesthetic agents, potential adverse effects of anaesthetic agents, and the acute management of seizures and refractory status epilepticus on the ICU. Relevant literature was identified by a Pubmed search of epilepsy and status epilepticus in conjunction with individual anaesthetic agents.

Recovery after ECT: comparison of propofol, etomidate and thiopental

OBJECTIVES

To compare post anesthetic time for patient recovery after electroconvulsive therapy, as measured by the post anesthetic Recovery Score of Aldrete and Kroulik, using three different types of hypnotic drugs (propofol, etomidate and thiopental).

METHOD

Thirty patients were randomized to receive one of the three drugs (n = 10 in each group), during a course of electroconvulsive therapy treatment. Patients and raters were blinded to which drug was received. Main treatment characteristics were recorded (as total electric charge received seizure threshold, number of treatments, and the mean time for recovery) along the whole treatment.

RESULTS

Thiopental and propofol were associated with a significance increase in charge needed to induce a seizure (p < 0.0001) when compared to etomidate, as well as a significant decrease of time for recovery (p = 0.042).

CONCLUSIONS

These findings suggest that, although there seems to be no difference in the clinical outcome across these three drugs, propofol offers the best recovery profile. However, it makes a higher mean electric charge necessary.

Cardiovascular effects of anesthesia in ECT: a randomized, double-blind comparison of etomidate, propofol, and thiopental

Cardiovascular alterations during electroconvulsive therapy (ECT) are a major concern for this treatment. Although several studies have been performed to compare the effects of anesthetics on these alterations, the results are mixed and doubt still exists regarding the choice of the best drug. We conducted a randomized, double-blind clinical trial to compare the effects of 3 anesthetics used in ECT: etomidate, propofol, and thiopental. Patients (N=30) were randomized to receive one of these drugs as the anesthetic for the ECT procedure. Cardiovascular evaluation consisted of the measurement of blood systolic and diastolic pressure and heart rate before and immediately after the end of the seizure for each patient during a course of ECT. The results showed that etomidate, propofol, and thiopental were associated with similar cardiovascular effects.

The effects of etomidate on seizure duration and electrical stimulus dose in seizure-resistant patients during electroconvulsive therapy

OBJECTIVE

Methohexital used to be the preferred anesthetic used in electroconvulsive therapy (ECT). Since 1999, there have been supply problems for this drug, and there has been no clear guidance regarding which anesthetic should be used preferably in ECT. Most clinics use thiopental or propofol, although these drugs may increase the seizure threshold. We investigated if etomidate improves seizure duration compared with thiopental in cases where eliciting seizures becomes problematic.

METHODS

During our routine delivery of ECT at a general psychiatric hospital in Cardiff, UK, we observed 5 patients who had ECT courses with thiopental and did not achieve adequate seizure duration despite very high electric stimulation. They later relapsed and received second courses of ECT under etomidate. We compared the seizure duration and the electric charge needed to produce the seizures for a total of 46 pairs of ECT sessions given under the 2 anesthetics on the same patients.

RESULTS

The average electric stimulation dose required to induce seizures was reduced from 638 to 497 millicoulombs (95% confidence interval, 60-221; P = 0.001). Despite the lower dose, the length of observed seizure duration increased by 10.3 seconds (65%) and that of the electroencephalograph-recorded duration increased by 8.7 seconds (41%) (P < 0.001).

CONCLUSIONS

Etomidate has a distinct advantage over thiopental in producing seizures of adequate duration during ECT and should be used as the first-line measure in augmenting seizures in patients who have very high seizure thresholds.

Customized anesthetic preservation of ictal threshold in electroconvulsive therapy: role of adjunctive remifentanil with etomidate

We present a case of anesthesia for electroconvulsive (ECT) therapy that was complicated by emetic sensitivity to etomidate, fragile ictal threshold, and mild pseudocholinesterase deficiency. The anesthetic was designed in this patient taking all his issues in consideration. The mild pseudocholinesterase deficiency necessitated a (50-75%) reduction in succinylcholine dosage, careful monitoring of the train of four, and postictal amnestic coverage to prevent paralysis upon waking. The significant emetic response to etomidate prompted substitution to propofol and preemptive ondansetron. Propofol significantly raised the ictal threshold but significantly reduced the postprocedural emesis. Eventually, this clinical challenge was resolved with adjunctive use of low-dose etomidate and remifentanil. This combination preserved the ictal parameters, providing patient comfort, good clinical response, and therapeutic efficacy. Although seizure duration and quality often are restored with hyperventilation and caffeine, this case necessitated a return to etomidate for the restoration of satisfactory ictal parameters. Although this effect of remifentanil has been described with methohexital, and etomidate with alfentanil, to the best of our knowledge, this is the first reported case of adjunctive remifentanil with etomidate for preserving ictal threshold. The outpatient course of ECT was thus completed with all psychiatric and anesthetic goals satisfied: adequate seizure quality and duration, no paralysis upon waking, no post-ECT nausea and vomiting, and patient satisfaction. Anesthesiologists should be aware of factors influencing the seizure duration and, keeping in mind the coexisting medical conditions of the patient, adjustments should be made to get the best possible outcome.

Effets comparés de l’étomidate et du propofol pour l’anesthésie lors de l’électroconvulsivothérapie

OBJECTIVE

Electroconvulsive therapy (ECT) requires repeated short-term anaesthesia with muscle relaxation and deep narcosis and uses several anaesthetic agents. The aim of this study was to assess the quality of the anaesthetic technique applied for ECT by comparing two products: propofol and etomidate.

METHODS

This was a prospective randomised study that included ECT sessions. Patients were distributed into two groups. Patients of Group 1 underwent general anaesthesia with propofol (1.5mg.kg(-1)) and succinylcholine (0.75 mg.kg(-1)). Patients of Group 2 were administered etomidate (0.15 mg.kg(-1)) and succinylcholine (0.75 mg.kg(-1)). None of the patients included had any absolute or relative contraindication to ECT.

RESULTS

104 sessions were included, with 52 sessions per group. Group 1 was composed of 12 patients and Group 2 of 13. The demographical characteristics and indication for ECT were comparable in the two groups. There was no haemodynamic variation (notably drop in blood pressure) between the groups. The duration of seizures was significantly more prolonged in the etomidate group (28.76 +/- 3.29 seconds) than in the propofol group (23.84 +/- 7.18 seconds), with significant difference (p = 0.000018). Awakening was calm in both groups.

CONCLUSION

The pharmacological properties of propofol and etomidate reply precisely to the requirements of anaesthesia for ECT. Nevertheless, no drop in blood pressure was observed with the greater prolongation of seizures in the etomidate group compared with the propofol group.

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

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

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

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

Propofol alone, sevoflurane alone, and combined propofol-sevoflurane anaesthesia in electroconvulsive therapy

Electroconvulsive therapy is an effective treatment for severe and medication-resistant depression. There have been no reports describing how a volatile anaesthetic affects haemodynamic responses, seizure duration, and recovery characteristics during electroconvulsive therapy. We carried out a repeated-measure crossover study to compare the effects on haemodynamic responses, seizure duration, and recovery characteristics of the following types of anaesthesia in electroconvulsive therapy: propofol alone, sevoflurane alone, and propofol combined with sevoflurane. We recruited 50 patients requiring electroconvulsive therapy for depression. For anaesthesia induction, 1.5 mg/kg propofol (condition P), 5% sevoflurane in oxygen following a vital capacity rapid inhalation induction (condition S), or 1.5 mg/kg propofol followed by 5% sevoflurane in oxygen (condition PS) was administered. Succinylcholine 1.5 mg/kg was then given. Electrical stimulation was administered after fasciculation. Measurements were obtained before anaesthesia induction (baseline), prior to succinylcholine administration, prior to electroconvulsive therapy, and at the peak after electroconvulsive therapy. After electroconvulsive therapy, peak heart rate and peak mean arterial pressure were highest in condition S. Whereas recovery time was longest in condition PS, motor seizure duration was significantly shorter than in either condition P or S. Electroencephalographic seizure duration was significantly shorter in condition PS than in condition P and significantly shorter in condition S than in condition P. Sevoflurane anaesthesia alone is most disadvantageous in terms of haemodynamics. Propofol-sevoflurane anaesthesia is advantageous in terms of haemodynamics, but disadvantageous in terms of seizure duration and recovery time. Propofol alone is most advantageous in terms of seizure duration.

Fetal heart rate decelerations during ECT-induced seizures: is it important?

Electroconvulsive therapy (ECT) is sometimes indicated during pregnancy and may offer advantages over pharmacotherapy for the patient and the fetus (1,2). However, very little data is available on the impact of epileptic or ECT-induced seizures on the fetus. We report a case of brief fetal heart rate decelerations in a fetus associated with maternal ECT-induced convulsions.

Augmentation of seizure induction in electroconvulsive therapy: a clinical reappraisal

OBJECTIVE

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

METHOD

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

RESULTS AND CONCLUSIONS

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

A switch from propofol to etomidate during an ECT course increases EEG and motor seizure duration

INTRODUCTION

Of 58 patients treated at our electroconvulsive therapy (ECT) unit early in the year 2000, 12 patients under propofol did not achieve a seizure duration of >30 s [electroencephalogram (EEG)] with a maximum stimulation charge of 504.0 mC (100%).

METHOD

A switch from propofol to etomidate was therefore undertaken in these patients at the next treatment to achieve longer seizure duration.

RESULTS

In 11 of the 12 patients, a remarkable increase in seizure duration was recorded after the change of anesthetic. The mean seizure duration increased from 18.6 to 43.4 s and remained at that level for the following ECT session. The increase was highly significant (t11 = 3.772, p < 0.001). The mean motor seizure also changed from 11.6 to 27.5 s (t11 = 5.560, p < 0.003) and remained there for the next treatment.

DISCUSSION

Our data show that the switch more than doubles EEG seizure duration and suggest that etomidate can be used instead of methohexital as an alternative in patients with short seizure duration. It is also a potential option to avoid the pain frequently associated with the injection of propofol.

Effects of propofol anesthesia on cognitive recovery of patients undergoing electroconvulsive therapy

The effects of different doses of propofol on post-electroconvulsive therapy (ECT) cognitive recovery were evaluated together with the effects on seizure duration and hemodynamic changes during ECT in 15 depressive patients. Propofol attenuated the increase in arterial blood pressure and heart rate in a dose-dependent manner compared with thiamylal. Propofol showed a clinically significant anticonvulsant effect during ECT in a dose-dependent manner. There were no significant differences among the four different induction groups in the mean recovery time from anesthesia, however, a low dose of propofol suppressed the early recovery of cognitive function. For early cognitive recovery after ECT, a deep anesthetic level is necessary when the traditional ECT apparatus is used which produces sine curve wave stimuli.

The comparative effects of methohexital, propofol, and etomidate for electroconvulsive therapy

The intravenous anesthetics which are commonly used for electroconvulsive therapy (ECT) possess dose-dependent anticonvulsant properties. Since the clinical efficacy of ECT depends on the induction of a seizure of adequate duration, it is important to determine the optimal dose of the hypnotic for use during ECT. We compared the duration of seizure activity and cognitive recovery profiles after different doses of methohexital, propofol, and etomidate administered to induce hypnosis prior to ECT. Ten outpatients with major depressive disorders receiving maintenance ECT participated in this prospective, randomized, cross-over study. Patients were premedicated with glycopyrrolate, 0.2 mg intravenously (i.v.), and labetalol, 20-30 mg i.v., and hypnosis was induced with an i.v. bolus injection of methohexital or propofol (0.75, 1.0, and 1.5 mg/kg), or etomidate (0.15, 0.2, and 0.3 mg/kg), administered over 10-15 s. Adequate muscle paralysis was achieved with succinylcholine, 1.0-1.4 mg/kg i.v. Each patient's seizure threshold was determined prior to enrollment in the study and the electrical stimulus variables were kept constant throughout the study period. After delivery of a bilateral electrical stimulus, the duration of the resulting electroencephalographic (EEG) and motor seizures were recorded. A total of 90 ECT treatments were evaluated. The durations of EEG and motor seizures were longest after etomidate and shortest after propofol. There were no significant dose-related differences in motor and EEG seizure durations (means +/- SD) after the low, intermediate, and high doses of etomidate of 44 +/- 11 and 77 +/- 19, 43 +/- 10 and 76 +/- 34, 42 +/- 16 and 78 +/- 56 s, respectively. Conversely, both methohexital and propofol, 0.75, 1.0, and 1.5 mg/kg, produced dose-dependent decreases in motor and EEG seizure durations (i.e., 37 +/- 10 and 58 +/- 12, 36 +/- 8 and 62 +/- 24, and 29 +/- 13 and 48 +/- 20 for methohexital; 34 +/- 15 and 56 +/- 29, 31 +/- 8 and 50 +/- 17, and 20 +/- 6 and 33 +/- 12 for propofol, respectively). The awakening times were similar, regardless of the hypnotic or dose administered.(ABSTRACT TRUNCATED AT 250 WORDS)