Critical care delirium: prevention, identification and management: a narrative review

Delirium is a frequent complication of critical illness and remains an important cause of short- and long-term morbidity for patients admitted to ICUs. Delirium is associated with prolonged mechanical ventilation; extended ICU and hospital stay; and longer-term health issues. Development is associated with patient (e.g. severe physiological derangement); clinical (e.g. sedation); and environmental factors (e.g. loss of day/night variation and sleep deprivation). This review provides an overview of the current understanding of ICU delirium and its implications for critical care practice.

We undertook a narrative review of the contemporary literature and synthesised evidence related to epidemiology, pathophysiology, risk factors, diagnostic tools and preventive and therapeutic strategies, with an aim of developing a practical resource for clinicians.

Delirium impacts approximately one-third of patients admitted to general ICUs, with higher rates among older adults and those requiring mechanical ventilation. Diagnosis relies on clinical assessment supported by validated instruments, each with limitations for the critically ill population. Pharmacological interventions have not shown consistent benefit to prevent or treat delirium. In contrast, multicomponent non-pharmacological approaches (e.g. optimal sedation, early mobilisation, re-orientation, sleep hygiene and family engagement) are associated with a reduced incidence of delirium and improved functional outcomes. Delirium contributes to the long-term psychological and cognitive burden of critical illness and structured follow-up and ICU diaries may support recovery.

Delirium in the ICU is common and important for patients and multidisciplinary critical care providers. The most effective strategies for prevention and management are non-pharmacological and require co-ordinated, multidisciplinary delivery. Sustained improvements in outcomes require consistent implementation of evidence-based care bundles and better integration of follow-up services for survivors.