Pharmacological and non-pharmacological interventions to prevent delirium in critically ill patients: a systematic review and network meta-analysis

Abstract

Purpose: To compare the effects of prevention interventions on delirium occurrence in critically ill adults.

Methods: MEDLINE, Embase, PsychINFO, CINAHL, Web of Science, Cochrane Library, Prospero, and WHO international clinical trial registry were searched from inception to April 8, 2021. Randomized controlled trials of pharmacological, sedation, non-pharmacological, and multi-component interventions enrolling adult critically ill patients were included. We performed conventional pairwise meta-analyses, NMA within Bayesian random effects modeling, and determined surface under the cumulative ranking curve values and mean rank. Reviewer pairs independently extracted data, assessed bias using Cochrane Risk of Bias tool and evidence certainty with GRADE. The primary outcome was delirium occurrence; secondary outcomes were durations of delirium and mechanical ventilation, length of stay, mortality, and adverse effects.

Results: Eighty trials met eligibility criteria: 67.5% pharmacological, 31.3% non-pharmacological and 1.2% mixed pharmacological and non-pharmacological interventions. For delirium occurrence, 11 pharmacological interventions (38 trials, N = 11,993) connected to the evidence network. Compared to placebo, only dexmedetomidine (21/22 alpha₂ agonist trials were dexmedetomidine) probably reduces delirium occurrence (odds ratio (OR) 0.43, 95% Credible Interval (CrI) 0.21-0.85; moderate certainty). Compared to benzodiazepines, dexmedetomidine (OR 0.21, 95% CrI 0.08-0.51; low certainty), sedation interruption (OR 0.21, 95% CrI 0.06-0.69; very low certainty), opioid plus benzodiazepine (OR 0.27, 95% CrI 0.10-0.76; very low certainty), and protocolized sedation (OR 0.27, 95% CrI 0.09-0.80; very low certainty) may reduce delirium occurrence but the evidence is very uncertain. Dexmedetomidine probably reduces ICU length of stay compared to placebo (Ratio of Means (RoM) 0.78, CrI 0.64-0.95; moderate certainty) and compared to antipsychotics (RoM 0.76, CrI 0.61-0.98; low certainty). Sedative interruption, protocolized sedation and opioids may reduce hospital length of stay compared to placebo, but the evidence is very uncertain. No intervention influenced mechanical ventilation duration, mortality, or arrhythmia. Single and multi-component non-pharmacological interventions did not connect to any evidence networks to allow for ranking and comparisons as planned; pairwise comparisons did not detect differences compared to standard care.

Conclusion: Compared to placebo and benzodiazepines, we found dexmedetomidine likely reduced the occurrence of delirium in critically ill adults. Compared to benzodiazepines, sedation-minimization strategies may also reduce delirium occurrence, but the evidence is uncertain.

Keywords: Critical care; Delirium; Non-pharmacological interventions; Pharmacological; Prevention.

Fig. 1

Summary of study retrieval and identification. Figure describes the flow of selection of included trials. Inclusion criteria applied included: randomized controlled trials, examined any pharmacological, sedation, non-pharmacological or multi-component intervention for prevention of delirium in critically ill adults

Fig. 2

Network plots for delirium prevention strategies for outcomes. Network geometry displays nodes as interventions and head-to-head direct comparisons as lines connecting these nodes. The width of the edges each representing a pairwise comparison was weighted by the corresponding number of studies, while the size of treatment nodes was weighted by the number of patients

Fig. 3

Forest plots with interventions ordered in descending order of SUCRA values for each network. All outcomes are reported as network odds or ratio of means with 95% credible intervals (Crl)