Effects of remifentanil on convulsion duration and hemodynamic responses during electroconvulsive therapy: a double-blind, randomized clinical trial

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.

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.

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.

A case of malignant catatonia with idiopathic pulmonary arterial hypertension treated by electroconvulsive therapy

BACKGROUND

Idiopathic pulmonary arterial hypertension (IPAH) is a progressive and fatal cardiovascular disease if left untreated. In patients with IPAH with psychiatric illness or other complications, careful attention is required when administering medical therapies that may affect their hemodynamics. Patients suffering from IPAH who undergo anesthesia and surgery have a high mortality and morbidity rate. We describe the treatment of intractable psychiatric symptoms with electroconvulsive therapy (ECT) in a patient with IPAH.

CASE PRESENTATION

A 23-year-old woman with IPAH and type I diabetes mellitus (DM) presented with malignant catatonia. Her heart function was classified as New York Heart Association (NYHA) class III. She required a rapid cure and ECT due to various psychiatric symptoms resistant to conventional medications. Pulmonary hypertensive (PH) crisis is the most concerning complication that can be induced by the sympathetic stimulation of ECT. To avoid PH crisis, we administered oxygen using a laryngeal mask and administered remifentanil for anesthesia. We also prepared standby nitric oxide for possible PH crisis, although it was ultimately not needed. With 14 ECT sessions, her malignant catatonia was ameliorated without physical complications.

CONCLUSION

ECT is an acceptable option for the treatment of medication-refractory psychiatric disturbances in patients with IPAH, provided careful management is assured to prevent or address complications.

The Effect of Adjuvant Remifentanil with Propofol or Thiopentone on Seizure Quality during Electroconvulsive Therapy

In order to optimise outcome to electroconvulsive therapy (ECT), there has been a trend to remifentanil as an adjunct to standard intravenous induction agents. This has allowed a reduction in the dose of anaesthetic agent, and usually an improved response to stimulation. However there have been no previous studies to ascertain whether this improvement is simply as a result of the reduced dose of anaesthetic agent or whether remifentanil itself might possess epileptogenic properties. This retrospective case-controlled study examined ECT outcomes, determined by electroencephalography (EEG) quality analysis, in patients who received ECT with or without remifentanil, where there was no dose reduction in the anaesthetic agent. There were no improvements seen in the measurements of any EEG parameter, including seizure duration. These observations suggest that remifentanil does not possess any intrinsic proconvulsant activity and that any improvement in outcome seen with its use is as a result of dose reduction in the IV anaesthetic agent.

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.