The aim of this study was to investigate the relationship between sleep disturbances and delirium in surgical ICU patients. The study set up to test the hypothesis that the occurrence of delirium is associated to the alteration of sleep quality and quantity observed in the critically ill patients.

Sleep disorders are an important clinical entity affecting outcome in respiratory, cardiovascular, metabolic and psychiatric disorders and exacting a potentially significant toll on patients at both a personal and socio-economic level.Delirium is a common organ dysfunction in the critically ill patients characterized by an acute onset of impaired cognitive function [REF] associated with prolonged ICU and hospital stay, nosocomial pneumonia, and death.

Inclusion Criteria:

• Adult, postsurgical patients who needed mechanical ventilation for more than 48 hr admitted to the general ICU

Exclusion Criteria:

• Defined a priori
• Were history of chronic dementia, psychosis, mental retardation, stroke syndrome or other primary neurologic disease
• Patient refusal to participate
• Alcohol and drug abuse.

ICU postsurgical patients who needed mechanical ventilation for more than 48 hr admitted to the general ICU