Mechanical ventilation: let us minimize sleep disturbances

This review provides a background in mechanical ventilation and sleep. Sleep pattern in mechanically ventilated patients differs largely from physiological sleep. The ventilatory mode and the ventilatory settings could have an influence on the sleep quality and quantity. Pressure support ventilation can increase the sleep fragmentation and decrease the sleep quantity, due to central apneas when compared with assist control ventilation. An excessive level of ventilatory assistance during sleep promotes central apneas and ineffective efforts. These two respiratory events can trigger arousals and awakenings, thus altering the sleep quality and quantity in mechanically ventilated patients. Ventilatory settings adjusted according to the patient's effort during pressure support allow reducing the number of ineffective efforts and improve sleep quality when compared with a clinical adjustment. A physiological approach to set the ventilator and the ventilatory mode may improve sleep quality and quantity. Minimizing the sleep alterations in mechanically ventilated patients could be obtained by setting the ventilator in such a way to avoid hyperventilation during the sleep stage. The impact of sleep derangements in patient outcomes is, however, unknown.