The comparative effects of propofol versus thiopentone on left ventricular function during electroconvulsive therapy

Influence of valproate on the required dose of propofol for anesthesia during electroconvulsive therapy of bipolar affective disorder patients

BACKGROUND

Propofol is often used as an anesthetic agent for electroconvulsive therapy (ECT). In recent studies, propofol was shown to possess significant seizure-shortening properties during ECT. "Valproate" is a mood stabilizer used mainly in the treatment of bipolar affective disorder. It is reported that valproate, being an anticonvulsant, raises the seizure threshold, thus decreases the efficacy of ECT treatment.

AIM

The purpose of our study was to compare the dose of propofol in valproate-using patients and valproate-free patients.

METHODS

In an open design, 17 patients with bipolar affective disorder manic episodes who were to be treated with valproate and ECT in combination, were compared with 16 manic-episode patients who were to be treated with ECT but not valproate. The two groups were compared on the basis of electroencephalography-registered seizure duration and the propofol dosage required to induce anesthesia.

RESULTS

Valproate, compared with no valproate treatment, results in a decrease in the propofol dose required to induce anesthesia. In the valproate group of study participants, seizure duration was significantly shorter than in the valproate-free group.

CONCLUSION

The results suggest that valproate reduces the dose of propofol required for anesthesia during ECT treatment in patients with bipolar affective disorder manic episodes. Although propofol is a safe and efficacious anesthetic for ECT treatment, lower doses of propofol should be used to induce anesthesia for patients under valproate treatment. When the clinician needs to prolong seizure duration in patients treated with valproate, interruption of the valproate treatment or an anesthetic agent other than propofol should be considered.

Effects of landiolol on left ventricular function during electroconvulsive therapy: a transthoracic echocardiographic study

The purpose of this study was to examine the effects of landiolol on left ventricular (LV) systolic function, using transthoracic echocardiography, during electroconvulsive therapy (ECT). Fourteen patients undergoing ECT were studied. Bilateral ECT was performed after administration of thiopentone (2 mg/kg), succinylcholine (1 mg/kg), and initiation of assisted mask ventilation with 100% oxygen. Patients received a bolus injection of landiolol (0.125 mg/kg) or saline immediately after anesthetic induction and prior to electrical shock. LV systolic function was examined by transthoracic echocardiography prior to anesthetic induction, throughout the ECT procedure, and for 10 min after the seizure. Electrical shock resulted in a significant decrease in fractional area change (FAC) when compared with the awake condition in the control group [FAC when awake: 48 +/- 3%; 1 min after ECT: 38 +/- 4%*; 2 min after ECT: 36 +/- 4%*; 3 min after ECT: 40 +/- 3%*; mean +/- standard deviation, *p < 0.05 compared with awake]. Landiolol infusion stabilized systemic hemodynamics and LV systolic function. The study demonstrated that landiolol is a suitable agent to minimize hemodynamic changes and transthoracic echocardiographic variability after ECT.

Methohexitone, propofol and etomidate in electroconvulsive therapy for depression: a naturalistic comparison study

BACKGROUND

Methohexitone has been the most widely used anaesthetic for electroconvulsive therapy (ECT). However, recent scarcity and erratic availability has led to use of other anaesthetics with differing effects upon ECT. We compared treatment parameters and response to ECT in patients anaesthetised with different anaesthetics in a routine clinical setting.

METHODS

This was a naturalistic retrospective casenote analysis of 81 consecutive courses of ECT (total 659 treatments) for major depression.

RESULTS

Three anaesthetics were compared: methohexitone (n=34), propofol (n=13) and etomidate (n=34). Mean seizure duration was lowest (p<0.0001) for propofol. However, mean stimulus charge was highest in the propofol group (p<0.0001) who required a greater increase in stimulus charge during the course of treatment and also experienced a greater proportion of failed seizures (</=15 s on EEG). Despite differing effects upon treatment parameters, choice of anaesthetic did not appear to significantly affect therapeutic response to ECT. Use of propofol may be associated with longer treatment course that could result in extra cost.

LIMITATIONS

This was a retrospective casenote study, in which patients were not randomised to anaesthetic and standardised outcome measures were not used. The small sample size in the propofol group may have reduced the power of the study to demonstrate other differences between propofol and the other anaesthetic groups. A formal economic analysis was not performed.

CONCLUSION

Individual anaesthetics differentially influence seizure duration and stimulus charge but final response to ECT appears not to be adversely affected.

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

OBJECTIVES

Our primary objective was to conduct a systematic review to determine the differential effects of general anesthetic agents on electroconvulsive therapy (ECT) induced motor and electroencephalogram seizure duration. Our secondary objective was to determine the differential effects of induction agents on emergence time, recovery time, and the occurrence of adverse cardiac events and drug effects.

MATERIALS AND METHODS

We searched 4 electronic databases for randomized, crossover, and parallel trials. The weighted mean difference was calculated for continuous variables, whereas the risk difference was assessed for dichotomous variables. We combined crossover- and parallel-designed trials using the inverse variance method, and the random-effects model was used throughout.

RESULTS

Forty-one randomized trials involving 14 induction agents were included. The quality of trials was poor. Clinical and statistical heterogeneity were identified throughout. The most commonly studied comparison was methohexital versus propofol, where the mean motor seizure duration with methohexital was longer compared with that of propofol (weighted mean difference, 9.06 seconds; 95% confidence interval, 5.72-12.40). However, combining methohexital or propofol with a short-acting opioid prolonged seizure duration. Small but significant variations in emergence and recovery times were identified. Inadequate data were available to draw conclusions regarding adverse cardiac events and drug effects. No deaths were reported.

CONCLUSIONS

Whereas the relationship between ECT seizure length and efficacy remains unclear, all of the available induction agents in this review would be appropriate for ECT. When the clinician needs to prolong seizure length, methohexital or the addition of a short-acting opioid to methohexital or propofol should be considered. The small variations in emergence and recovery times should not govern the choice of an induction agent.

Effects of antihypertensive medication on left ventricular function during electroconvulsive therapy: study with transthoracic echocardiography

STUDY OBJECTIVE

To characterize the effects of antihypertensive medications on cardiac function using transthoracic echocardiography during electroconvulsive therapy (ECT).

STUDY DESIGN

Randomized, double-blind study set at a university hospital.

PATIENTS

30 American Society of Anesthesiologists (ASA) physical status I and II patients undergoing ECT.

INTERVENTIONS

Patients were given thiopental sodium (two mg/kg) and succinylcholine (one mg/kg), and mask ventilation was initiated with 100% oxygen before bilateral ECT. Patients received a bolus injection of one of several different antihypertensive medications: 0.08 mg/kg alprenolol, 0.01 mg/kg nitroglycerin, 0.02 mg/kg nicardipine, or saline immediately after anesthesia induction and before electrical shock.

MEASUREMENTS

Cardiac function was examined through transthoracic echocardiography before anesthesia induction, throughout the ECT procedure, and for 10 minutes after the seizure.

MAIN RESULTS

Electrical shock resulted in a significant change in fractional area change when compared with the awake condition. Further fractional area change at one minute after ECT was significantly higher in patients who received nicardipine than in the other groups (means +/- SD): control group, 43% +/- 10%; nitroglycerin group, 46% +/- 8%; nicardipine group, 65% +/- 6% (P < 0.05 vs the other three groups); and alprenolol group, 51% +/- 7%. Systolic blood pressure/end-systolic area-end-diastolic area at one minute after the electrical shock was higher in the control, nitroglycerin, and alprenolol groups but not in the nicardipine group when compared with the awake condition (means +/- SD): control group, 39 +/- 8 mmHg/cm(2) (P < 0.05 vs the other three groups); nitroglycerin group, 32 +/- 9 mmHg/cm(2); nicardipine group, 29 +/- 7 mmHg/cm(2); alprenolol group, 31 +/- 6 mmHg/cm(2).

CONCLUSIONS

Specific antihypertensive drugs produced different hemodynamic effects during ECT. Our data suggest that alprenolol was the most appropriate agent for minimization of changes in heart rate and transthoracic echocardiographic variables after ECT.

Indications for the use of propofol in electroconvulsive therapy

BACKGROUND

Propofol is an anesthetic agent commonly used for ambulatory surgery because is associated with rapid recovery and a benign side effect profile. In electroconvulsive therapy (ECT), its use is limited because of its seizure-shortening effects, and is recommended only for patients with preexisting cardiac conditions requiring attenuated hemodynamic response during treatment. We have identified two additional significant indications for propofol: to induce shorter seizures in patients with prolonged seizures and to minimize post-ictal nausea and vomiting.

METHODS

We reviewed the records of 340 patients treated with ECT. We identified 28 patients who were switched from methohexital to propofol anesthesia due to adverse effects or to avoid prolonged seizures.

RESULTS

Twenty-two patients were switched from methohexital anesthesia to propofol because they had already experienced long seizures. Nine patients had seizures longer than 180 seconds requiring termination with a benzodiazepine. The switch resulted in an average shortening of the EEG recorded seizures by 38.7%. Eight of the 22 (36.4%) patients were adolescents. These 8 comprised 53% of the total of 15 adolescents treated with ECT in our service. Five of the 15 (33%) had seizures longer than 180 seconds. Finally, 7 of the 28 patients were switched to propofol because of nausea and vomiting, which was significantly reduced. No side effects were noted, and none of these patients needed to switch back to methohexital.

CONCLUSION

Propofol may be a useful alternative to methohexital for the treatment of patients who have excessively long seizures and/or severe nausea and vomiting after ECT. Such seizures are more common among adolescents.