Delirium in ICU Patients after Cardiac Arrest: A Scoping Review

Introduction: The incidence of delirium in the intensive care unit is high, although it may differ according to the specific characteristics of the unit. Despite the rapid development of research on delirium in recent years, the pathophysiological mechanisms leading to the clinical presentation of delirium are still subject to hypotheses. The aim of this review was to describe the incidence of delirium in cardiac arrest survivors and the clinical impact of delirium on patient outcomes. Methods: A scoping review was conducted in the second quarter of 2022. The number of articles retrieved during each search test was limited to studies conducted between 2010 and 2020. Strict inclusion and exclusion criteria were applied. The last search was conducted in May 2022. Results: A total of 537 records was initially obtained from the databases. After discarding duplicates, selecting titles and abstracts, and then analyzing full-text articles, 7 studies met the inclusion criteria. The incidence of delirium in the cardiac arrest survivor population ranged from 8% to as high as 100%. The length of stay in ICU and hospital was significantly longer in patients with delirium than those without. Ninety-eight percent of patients had cognitive or perceptual impairment and psychomotor impairment. Of the seven studies included in the analysis, the RASS, CAM, and NuDesc scales were used to diagnose delirium. Potential risk factors that may influence the duration of delirium include age and time since resuscitation; propofol use shortened the duration of delirium. Conclusion: the incidence of delirium in ICU patients who survived CA is high. Cardiac arrest is an additional predisposing factor for delirium. In cardiac arrest survivors, the occurrence of delirium prolongs the duration of ICU and hospital stay and adversely affects functional outcomes. The most common type of delirium among this population was hypoactive delirium. A large percentage of patients manifested symptoms such as cognitive or perception impairment, psychomotor impairment, and impaired concentration and attention.