A systematic review of modified electroconvulsive therapy (ECT) to treat delirium

Delirium is costly for patients, carers, and healthcare systems. In addition, non-pharmacological and pharmacological management of delirium is challenging. Electroconvulsive therapy (ECT) has been proposed and used as an anecdotal treatment of delirium in clinical practice. However, the efficacy and safety of this approach are not well understood.

To synthesise and review the evidence relating to the safety and efficacy of ECT as a treatment for delirium.

A systematic review was completed according to PRISMA guidelines using the PubMed, CINAHL, Cochrane Library, and PsycINFO databases. Studies were eligible for inclusion if modified ECT was used to treat delirium symptoms. ECT for delirium in people with neuroleptic malignant syndrome, catatonia, or confusional states associated with acute primary psychiatric conditions were excluded. All included records were first ranked using the hierarchy of evidence-based medicine; quality was then assessed using the Joanna Briggs critical appraisal checklists. Pooled data across the cases identified were analysed using descriptive statistics.

Of 1226 records screened, 10 studies met inclusion criteria: six case reports, three case series, and one quasi-experimental study. The literature base was of mixed quality. A single quasi-experimental study was assessed to be of 'fair' quality, the remainder of the case series and case reports were rated as 'poor' to 'fair' quality. A total of only 40 individual people with delirium who were treated with ECT were identified. In 33/40 cases, the aetiology of delirium was substance withdrawal. The number of ECT treatments administered ranged from 1 to 13. ECT was reported to positively contribute towards treatment of delirium in all cases, although objective measures of improvement were reported in only 6/13 patient cases from case reports and case series (46%). The singular quasi-experimental study reported a statistically significant decrease in duration of delirium, time spent in physical restraint, and in benzodiazepine requirement when ECT was used as an adjunct in benzodiazepine withdrawal delirium. When adverse events were described these included mild confusion and memory deficits; all were reported as time limited and reversible. Considerable limitations in the quality of the evidence base were identified, including the risk of selection, publication and reporting bias. Much data reporting on safety and efficacy of ECT in delirium was missing.

There is insufficient literature to support modified ECT as a clinical treatment for delirium. The few studies identified were generally of weak evidence lacking important data on safety and objective outcome measures, and not including populations with broad delirium aetiologies. Further research using more robust methodologies and broader populations (age, aetiology) of people with delirium treated with ECT is needed.