مقایسه متاهکسیتایل و اتومیدیت به عنوان عوامل بیهوشی برای الکتروشوک درمانی در اختلالات عاطفی و روانی

Background ECT is a well-established treatment for severe depression. The available data on psychosis are limited, but reliable. Its therapeutic potential relies on the induction of a generalized seizure. Besides other narcotics, methohexital and etomidate are used for general anesthesia in ECT. Since prolonged seizures have been reported following the use of etomidate, it can be deduced that the substances might differ in their anticonvulsant properties, resulting in a lower increase in stimulus intensity during the course of treatment under etomidate. Besides this hypothesis, we aimed to investigate the differential effects of etomidate and methohexital on clinical features, ECT parameters and side effects of the treatment. Methods We performed a retrospective analysis of treatment data of patients with affective and psychotic diagnosis who received general anesthesia for ECT either with etomidate or with methohexital. Results ECT with etomidate and methohexital was equally effective. During the course of therapies the administered electric charge increased significantly and equally in both treatment groups. In the methohexital group, but not in the etomidate group, electroencephalographic seizure duration had a declining trend during the course of therapies. We observed more side effects during and immediately after ECT in the methohexital group than in the etomidate group. Limitations The limitations of this study are that the patients received various psychotropic co-medications, which influence ictal parameters differently, and, secondly, the study is based on a retrospective analysis. Conclusion The results of our analysis suggest that etomidate and methohexital affect ictal parameters to different extents. Longer seizure duration and fewer side effects are in favor of etomidate.

Electroconvulsive therapy (ECT) is a well-established, highly effective treatment for severe depression. The available data on psychosis are limited, but reliable (The UK ECT Review Group, 2003; Zervas et al., 2012). Although the exact therapeutic mechanisms remain to be clarified, repeated induction of a generalized seizure is viewed as decisive for a therapeutic response (Sackeim et al., 1991). General anesthesia and muscular relaxation are performed in order to prevent injuries during the seizure. Cognitive-mnestic impairments are the most frequent severe side effects (The UK ECT Review Group, 2003). Although these impairments have been shown to be fully reversible (The UK ECT Review Group, 2003), they are usually perceived by patients as being very defacing, and sometimes to such an extent as to render a further administration of ECT impossible. Besides electrode placement, the electric charge needed for seizure induction has been shown to be a pivotal parameter influencing cognitive side effects (Weiner et al., 1986). Thus, all measures that lead to a reduction of the electric charge might also help reduce cognitive side effects. There is widespread consensus that a generalized seizure of sufficient duration is necessary for the therapeutic effect of the treatment (American Psychiatric Association, 2001), but this alone is likely not sufficient (Robin and De Tissera, 1982; Sackeim et al., 2000). While recent studies have sought to identify EEG measures that are able to predict ECT outcome (Perera et al., 2007), the notion that ictal parameters influence therapeutic properties of ECT continues to persist. Higher amplitudes of the ictal EEG, especially in the δ-band, greater ictal coherence, stronger postictal suppression and a higher peak seizure heart rate are associated with greater success of the treatment (Perera et al., 2004; Folkerts, 1996). There is no relationship between seizure duration and ECT-effectiveness (Swartz, 2001). Since seizures are longer under the influence of etomidate than under the influence of methohexital (Eranti et al., 2009), it can be assumed that the anticonvulsant effect seen by the gain of electric charge necessary to elicit a sufficient seizure is smaller after etomidate than after methohexital. One of the aims of this study was to test this hypothesis. Besides this, we wanted to test if the choice of the narcotic had an effect on other ictal and treatment parameters. Since the choice of the narcotic might influence both the main effect and the side effects induced by ECT, a better characterization of the narcotics used in ECT is needed for further optimization of this treatment. Here we present a retrospective study with subjects who underwent ECT for clinical reasons in order to treat their affective disorder or their schizophrenia. One part of the patients received general anesthesia with methohexital, a short acting barbiturate, while the other part of the patients received etomidate, a non barbiturate. We sought to evaluate if these two patient groups differed in electric stimulation dose, main effect and the treatment's side effects. Moreover, we examined whether the group that improved better during ECT differed from the one that improved less in any other aspect.

Acknowledging the caveats listed above, our study was able to show that ECT with etomidate and methohexital is equally effective. However, there were significantly fewer side effects with etomidate than with methohexital. In particular, there were fewer cardiovascular side effects, like bradycardia, cardiac arrhythmia and hypertension, requiring acute intervention. This aspect is of clinical relevance, especially with regard to the treatment of the elderly, who suffer from cardiovascular comorbidities more frequently. For these patients, etomidate should be preferred as a narcotic.