Sleep Quality, Circadian Rhythm Stability and Changes in Delirium State in Predicting Mortality Risk in Intensive...

Area of Science:

• Critical Care Medicine
• Neuroscience
• Sleep Medicine

Background:

• Delirium is a frequent and prognostically significant neuropsychiatric complication in intensive care units (ICUs).
• Understanding factors influencing delirium development and outcomes is crucial for improving patient care.

Purpose of the Study:

• To investigate the association between sleep quality and circadian rhythm stability, measured by actigraphy, and delirium states in ICU patients.
• To assess the predictive value of these sleep and circadian parameters for mortality risk in the ICU population.

Main Methods:

• A prospective observational study involving 74 adult ICU patients over 72 hours.
• Actigraphy was used to measure total sleep time (TST), wake after sleep onset (WASO), and circadian rhythm stability (r24).
• Delirium was assessed using the Confusion Assessment Method for the ICU (CAM-ICU) and categorized as no delirium, prolonged, or new-onset.

Main Results:

• Mortality rates were significantly higher in patients with prolonged delirium (45%) and new-onset delirium (45%) compared to those without delirium (13.3%).
• Lower circadian rhythm stability (r24) was associated with prolonged delirium, while increased WASO was linked to both prolonged and new-onset delirium.
• Multivariate analysis identified prolonged delirium and SOFA scores as independent predictors of mortality.

Conclusions:

• Sleep continuity (WASO) and circadian rhythm stability (r24) are closely associated with delirium state changes in ICU patients.
• Lower r24 predicts prolonged delirium and higher mortality, whereas higher WASO is related to new-onset delirium.
• Continuous monitoring of sleep and circadian rhythms, incorporating WASO into risk assessments, is recommended for timely interventions and improved ICU care quality.