Sleep-Promoting Strategies

The architecture of sleep is profoundly altered in critically ill patients. Up to 60% of ICU survivors report poor sleep quality or sleep deprivation. Sleep in ICU patients is characterized by a longer onset and a poorer sleep efficiency, as demonstrated by the prevalence of light sleep (N1 and N2 stages), a reduction or absence of deep phase (N3 stage) and REM sleep, and increased sleep fragmentation. The amount of total sleep time (TST) in 24-hour period is generally preserved, but this reflects abnormal daytime sleep (up to the 40–50% of TST) with short periods of nocturnal sleep. Disruption of sleep architecture has deleterious consequences on the homeostasis of cardiovascular, respiratory, and nervous systems, exposing patients to an increased risk of myocardial infarction, prolonged mechanical ventilation, and cognitive dysfunction. Factors associated with sleep disruption in the ICU include noise, lighting, nursing care interventions, pain, discomfort, mechanical ventilation, medications, and delirium. Although clinical trials are lacking, potentially valuable approaches to ameliorate sleep quality in the ICU include reducing noise and pain, promoting patient ventilator synchrony, and managing delirium.