Benzodiazepines for treatment of patients with delirium excluding those who are cared for in an intensive care unit

Background: Delirium is a very common condition associated with significant morbidity, mortality, and costs. Current critical care guidelines recommend first and foremost the use of nonpharmacological strategies in both the prevention and treatment of delirium. Pharmacological interventions may augment these approaches and they are currently used widely in clinical practice to manage the symptoms of delirium. Benzodiazepines are currently used in clinical practice to treat behavioural disturbances associated with delirium but current guidelines do not recommend their use for this indication. The use of these medicines is controversial because there is uncertainty about whether they are effective for patients or have the potential to harm them.

Objectives: To assess the effectiveness and safety of benzodiazepines in the treatment of delirium (excluding delirium related to withdrawal from alcohol or benzodiazepines) in any healthcare settings other than intensive care units (ICU).

Search methods: We searched ALOIS: the Cochrane Dementia and Cognitive Improvement Group's Specialized Register up to 10 April 2019. ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases (including MEDLINE, Embase, PsycINFO, CINAHL, LILACS), numerous trial registries (including national, international and pharmaceutical registries), and grey literature sources.

Selection criteria: We included randomised controlled trials (RCTs) conducted in healthcare settings that ranged from nursing homes and long-term care facilities to any hospital setting except for ICUs, involving adult patients with delirium excluding those with delirium related to alcohol or benzodiazepine withdrawal. Included RCTs had to assess the effect of benzodiazepines, at any dose and given by any route, compared with placebo or another drug intended to treat delirium.

Data collection and analysis: Two review authors independently assessed study eligibility, extracted data, and assessed the risk of bias of included studies. We decided whether or not to pool data on the basis of clinical heterogeneity between studies. We used GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods to assess the quality of evidence.

Main results: We identified only two trials that satisfied the selection criteria. We did not pool the data because of the substantial clinical differences between the trials. In one trial, participants (n = 58) were patients in an acute palliative care unit with advanced cancer who had a mean age of 64 years. All of the participants had delirium, were treated with haloperidol, and were randomised to receive either lorazepam or placebo in combination with it. Due to very serious imprecision, all evidence was of low certainty. We were unable to determine whether there were clinically important differences in the severity of delirium (mean difference (MD) 2.10, 95% CI -0.96 to 5.16; n = 50), length of hospital admission (MD 0.00, 95% CI -3.45 to 3.45; n = 58), mortality from all causes (risk ratio (RR) 0.33, 95% CI 0.04 to 3.02; participants = 58) or any of a number of adverse events. Important effects could not be confirmed or excluded. The study authors did not report the length of the delirium episode. In the other trial, participants (n = 30) were patients in general medical wards with acquired immune deficiency syndrome (AIDS) who had a mean age of 39.2 years. Investigators compared three drug treatments: all participants had delirium, and were randomised to receive lorazepam, chlorpromazine, or haloperidol. Very low-certainty evidence was identified, and we could not determine whether lorazepam differed from either of the other treatments in the effect on severity of delirium, any adverse event, or mortality from all causes. The study authors did not report the length of the delirium episode or the length of hospital admission.

Authors' conclusions: There is no enough evidence to determine whether benzodiazepines are effective when used to treat patients with delirium who are cared for in non-ICU settings. The available evidence does not support their routine use for this indication. Because of the scarcity of data from randomised controlled trials, further research is required to determine whether or not there is a role for benzodiazepines in the treatment of delirium in non-ICU settings.