Cognitive impairment in critically ill patients and former critically ill patients: A concept analysis.

Objectives: This concept analysis aimed to clarify the meaning of the concept of cognitive impairment in critically ill patients throughout the trajectory of their rehabilitation during and after an intensive care unit admission.

Review Methods Used: This study used concept analysis based on Rodgers' evolutionary method.

Data Sources: A systematic search was conducted in Cumulative Index to Nursing and Allied Health Literature, Public MEDLINE, and American Psychological Associations PsycINFO. The web was searched for grey literature.

Review Methods: Overall search terms used were "patients with cognitive impairments" AND "intensive care unit". Literature published between 2008 and 2022 was included and screened by title and abstract using systematic review software. The descriptive analysis focussed on surrogate terms/related concepts, attributes, and contextual basis.

Results: Thirty studies were included, representing variability in study design and country of origin. The analysis uncovered descriptions of the general terminology and the temporal trajectory of the concept, spanning from the acute phase to a long-term perspective. Attributes of the concept were described as delirium and domains of cognition. Antecedents were juxtaposed to risk factors, which were multifactorial. Consequences of cognitive impairment related to patients' quality of life, such as a decline in their ability to function independently, return to work, and manage everyday life. Also, cognitive impairment was identified as a significant public health problem.

Conclusion: Cognitive impairment is a complex concept with many surrogate and related terms. Furthermore, the concept is inextricably intertwined with the concepts of delirium and post-intensive care syndrome. Cognitive impairment may manifest as symptoms that can be challenging to identify and assess due to limitations in current screening tools and the absence of a consensus on timing. In relation to assessment and preventive strategies, the findings underline the need to distinguish between acute and long-term cognitive impairment.

Registration: There is no study registration number.