Sommeil en réanimation

Sleep pattern in Intensive Care Unit (ICU) patients differs largely from physiological sleep. The ICU environment, the acuity of illness, the hypnotics and the sedatives could have an influence on the sleep quality and quantity. The ventilatory mode and the ventilatory settings may influence the sleep pattern. Pressure support ventilation is a ventilatory mode largely used for weaning purposes. An excessive level of pressure support can increase the sleep fragmentation due to central apneas and to ineffective efforts. These two respiratory events can trigger arousals and awakenings, the sleep fragmentation, thus altering the sleep quality. The metabolic demand is diminished during the sleep stage, and an adequate level of ventilatory assistance during wakefulness can be excessive during sleep. The impact of sleep derangements in ICU patients' outcomes is unknown. The optimization of the ventilatory settings aim to avoid an excessive ventilatory assistance could improve sleep quality in mechanically ventilated ICU patients. A deeper understanding of the sleep physiopathology could help to elucidate its impact in the patients' outcomes.