Biomarkers in delirium: A systematic review

Area of Science:

• Neuroscience
• Biochemistry
• Clinical Medicine

Background:

• Delirium is a prevalent neuropsychiatric disorder linked to extended hospitalization, increased morbidity, and mortality.
• Accurate diagnosis of delirium is often challenging due to variable presentations and the absence of standardized diagnostic tools.
• Identifying reliable biomarkers is crucial for improving delirium detection and patient outcomes.

Purpose of the Study:

• To systematically review and examine biomarkers as potential diagnostic or prognostic indicators for delirium.
• To provide a foundation for future research into delirium biomarkers.
• To assess the current evidence supporting biomarker use in delirium diagnosis.

Main Methods:

• A systematic literature review was conducted for studies published between January 2000 and June 2019.
• Searches encompassed major databases including PubMed, Web of Science, CINAHL, EMBASE, COCHRANE, and Medline.
• Seventy-three observational studies assessing fourteen different biomarkers met the inclusion criteria.

Main Results:

• A total of 2082 relevant papers were identified, with 73 meeting inclusion criteria.
• Various biomarkers were assessed, but no single marker demonstrated sufficient evidence for routine diagnostic use.
• Study methodologies, including delirium assessment tools (DSM criteria, CAM, CAM-ICU) and severity scales (DRS), exhibited significant heterogeneity.

Conclusions:

• Current evidence does not support the use of any single biomarker for delirium diagnosis.
• Certain biomarkers showed promising associations and warrant further investigation in future studies.
• Standardization of clinical assessment methods and consideration of confounders like inflammation and comorbidities are recommended for future research.