Dosing and effectiveness of ketamine anesthesia for electroconvulsive therapy (ECT): a case series

Contemporary Anesthetic Evaluation and Management for Electroconvulsive Therapy

Electroconvulsive therapy (ECT) is a medical treatment most often used in patients with severe major depression that has not responded to other treatments. ECT is also indicated for patients with other severe psychiatric conditions, including bipolar disorder, schizophrenia, schizoaffective disorders, catatonia, and neuroleptic malignant syndrome. Contemporary "modified ECT" involves inducing general anesthesia with neuromuscular blockade before inducing the therapeutic seizure. The goal of this review is to combine an evidence-based update with the experience of the author's institution to provide a practical approach to anesthetic care for the patient undergoing ECT.

Real-world effectiveness of ketamine in treatment-resistant depression: A systematic review & meta-analysis

Ketamine is a promising therapeutic option in treatment-resistant depression (TRD). The acute efficacy of ketamine in TRD has been demonstrated in replicated randomised-controlled trials (RCTs), but the generalizability of RCT data to real-world practice is limited. To this end, we conducted a systematic review (Search date: 25/12/2021; 1482 records identified) and meta-analysis of studies evaluating the real-world clinical effectiveness of ketamine in TRD patients. Four overlapping syntheses (Total n = 2665 patients; k = 79 studies) and 32 meta-regressions (Total n = 2050; k = 37) were conducted. All results suggest that the mean antidepressant effect is substantial (mean ± 95% CI, % responded = 45 ± 10%; p< 0.0001, % remitted = 30 ± 5.9%; p< 0.0001, Hedges g of symptomatological improvement = 1.44 ± 0.609; p < 0.0001), but the effect varies considerably among patients. The more treatment-resistant cases were found to remit less often (p < 0.01), but no such effect on response was evident (p > 0.05). Meta-regressions also confirmed that the therapeutic effect does not significantly decline with repeated treatments (p > 0.05). These results demonstrate that even the most treatment-resistant patients may benefit from ketamine, and that mid-to-long term treatment is effective in many patients.

S -ketamine compared to etomidate during electroconvulsive therapy in major depression

Objective of the study was to compare two commonly used anesthetic drugs, S-ketamine and etomidate, regarding their influence on seizure characteristics, safety aspects, and outcome of electroconvulsive therapy (ECT) in major depression. Treatment data of 60 patients who underwent a total number of 13 ECTs (median) because of the severe or treatment-resistant major depressive disorder (DSM-IV) were analyzed. Etomidate, mean dosage (SD) = 0.25 (0.04) mg/kg, was used for anesthesia in 29 participants; 31 patients received S-ketamine, mean dosage (SD) = 0.96 (0.26) mg/kg. Right unilateral brief pulse ECTs were performed. The number of ECTs was individually adjusted to clinical needs, mean (SD) = 13.0 (4.3). Seizure characteristics, adverse events, and the clinical global impression (CGI) scores were compared between the both groups during ECT series. In the S-ketamine group, a lower initial seizure threshold (p = 0.014), stimulation charge (p < 0.001), higher postictal suppression (p < 0.001), EEG ictal amplitude (p = 0.04), EEG coherence (p < 0.001) and maximum heart rate (p = 0.015) were measured. Etomidate was associated with more frequent abortive seizures (p = 0.02) and restimulations (p = 0.01). The CGI scores, the number of sessions within an ECT series, and the incidence of adverse events did not differ between groups. Due to its lower initial seizure threshold, S-ketamine might hold a potential to become a clinically favorable anesthetic agent during ECT. However, the current findings should be interpreted with caution, and further prospective randomized clinical trials are required. Also, specific adverse effects profile of S-ketamine, especially with regard to the cardiovascular risk, needs to be taken into account.

Dexmedetomidine for the management of postictal agitation after electroconvulsive therapy with S-ketamine anesthesia

OBJECTIVES

Postictal agitation (PIA) represents one of the most common complications during a modified electroconvulsive therapy (ECT) course. Its clinical management can be challenging especially in cases with poor response to benzodiazepines. Dexmedetomidine, a highly selective alpha-2 adrenoceptor agonist acting predominantly in the locus coeruleus, exerts sedative effects without causing relevant respiratory depression. To the best of our knowledge, this is the first study that aimed to assess the impact of dexmedetomidine use with S-ketamine anesthesia on PIA reduction in ECT.

PATIENTS AND METHODS

We retrospectively analyzed 7 patients who underwent 178 ECT sessions with S-ketamine anesthesia between June 2011 and July 2015 at the Central Institute of Mental Health Mannheim. In 101 sessions, the patients received dexmedetomidine in combination with S-ketamine anesthesia. The decision for dexmedetomidine use was based on individual clinical presentation (patients with positive PIA history). A multivariate repeated measurement logistic regression analysis was conducted to investigate the effect of dexmedetomidine use on the occurrence of PIA. We hypothesized that the use of dexmedetomidine reduced the incidence of PIA also in combination with S-ketamine anesthesia.

RESULTS

The prevalence of PIA in ECT sessions with dexmedetomidine administration was lower (mean per patient, 34% vs 62%). In the multivariate logistic regression analysis, the use of dexmedetomidine predicted the non-occurrence of PIA in a highly significant manner (P=0.001, z=-3.83, odds ratio =0.011-0.303).

CONCLUSION

Adjunctive use of dexmedetomidine to S-ketamine anesthesia in ECT seems to be a promising tool for the management of intractable PIA syndrome.

Mood and neuropsychological effects of different doses of ketamine in electroconvulsive therapy for treatment-resistant depression

BACKGROUND

Treatment-resistant depression (TRD) is a growing clinical challenge. Electroconvulsive therapy (ECT) is an effective tool for TRD treatment. However, there remains a subset of patients who do not respond to this treatment with common anesthetic agent. Ketamine, a noteworthy anesthetic agent, has emerged as an augmentation to enhance the antidepressant efficacy of ECT. Trials of i.v. ketamine in TRD indicated dose-related mood enhancing efficacy. We aimed to explore anesthetic and subanesthetic concentrations of ketamine in ECT for TRD with respect to their impact on mood and neuropsychological effects.

METHODS

Ninety TRD patients (36 males, 54 females; average age, 30.6 years old) were randomly assigned to receive either ketamine (0.8mg/kg) (n=30), subanesthetic ketamine (0.5mg/kg) plus propofol (0.5mg/kg) (n=30) or propofol (0.8mg/kg) (n=30) as an anesthetic and underwent 8 ECT sessions. The primary outcome measures were the 17-item Hamilton Depression Rating Scale (HDRS-17), cognitive assessments and seizure parameters.

RESULTS

The ketamine group had an earlier improvement in HDRS-17, longer seizure duration, lower electric quantity, a higher remission rate, and a lower degree of executive cognitive impairment compared to the ketamine+propofol and propofol groups. The ketamine+propofol group showed earlier improvement in the HDRS-17, a longer seizure duration and a different seizure energy index when compared to the propofol group.

LIMITATIONS

The postoperative dissociative side effect was not assessed.

CONCLUSIONS

Both anesthetic and subanesthetic concentrations of ketamine have rapid mood enhancing actions in ECT for TRD, while anesthetic concentrations results in larger magnitudes of antidepression and cognitive protection. ECT with ketamine anesthesia might be an optimized therapy for patients with TRD.

Further improving the cognitive effect profile of electroconvulsive therapy (ECT): the case for studying carbamylated erythropoietin

Electroconvulsive therapy (ECT) remains the most effective acute treatment for severe depression and several other psychiatric illnesses. However, its use has been limited by concerns about cognitive adverse effects. ECT may cause temporary cognitive impairment in some patients, typically anterograde amnesia for 1-2 weeks after a course of treatment, and circumscribed retrograde amnesia. These cognitive effects largely disappear within days to weeks after treatment. Efforts to find a pharmacological agent to reduce the cognitive effects of ECT have largely been unsuccessful, with the possible exception of thyroid hormone. We review the literature on pharmacological attempts to attenuate ECT's cognitive effects, and propose a novel neuroprotective and neurotrophic agent, carbamylated erythropoietin (CEPO), for this indication.