Objective:

To summarize current knowledge on sleep and circadian rhythm alterations in adult ICU patients and examine their associations with clinical outcomes.

Key Findings:

• Disrupted sleep architecture is linked to prolonged mechanical ventilation and weaning failure.
• Alterations in sleep and circadian rhythms correlate with delirium and acute brain dysfunction.
• Circadian rhythm disruption is associated with systemic inflammation, disease severity, and adverse prognosis.
• Sleep and circadian disturbances may persist post-ICU discharge, contributing to cognitive impairment and reduced quality of life.

Interpretation:

The evidence indicates that sleep and circadian rhythms are relevant to critical illness severity and brain dysfunction.

Limitations:

• Methodological limits in existing studies.
• Need for rigorous interventional trials to confirm findings related to sleep and circadian rhythms.

Conclusion:

The review emphasizes the importance of sleep and circadian rhythms in critically ill patients.