To compare sleep quality between two types of ventilators commonly used for noninvasive ventilation: conventional ICU ventilators and dedicated noninvasive ventilators; and to evaluate sleep during and between noninvasive ventilation sessions in critically ill patients.Design:
Physiological sleep study with a randomized assessment of the ventilator type.Setting:
Medical ICU in a university hospital.Patients:
Twenty-four patients admitted for acute hypercapnic respiratory failure requiring noninvasive ventilation.Interventions:
Patients were randomly assigned to receive noninvasive ventilation with either an ICU ventilators (n = 12) or a dedicated noninvasive ventilators (n = 12), and their sleep and respiratory parameters were recorded by polysomnography from 4 PM to 9 AM on the second, third, or fourth day after noninvasive ventilation initiation.Measurements and Main Results:
Sleep architecture was similar between ventilator groups, including sleep fragmentation (number of arousals and awakenings/hr), but the dedicated noninvasive ventilators group showed a higher patient–ventilator asynchrony-related fragmentation (28% [17–44] vs. 14% [7.0–22]; p = 0.02), whereas the ICU ventilators group exhibited a higher noise-related fragmentation. Ineffective efforts were more frequent in the dedicated noninvasive ventilators group than in the ICU ventilators group (34 ineffective efforts/hr of sleep [15–125] vs. two [0–13]; p < 0.01), possibly as a result of a higher tidal volume (7.2 mL/kg [6.7–8.8] vs. 5.8 [5.1–6.8]; p = 0.04). More sleep time occurred and sleep quality was better during noninvasive ventilation sessions than during spontaneous breathing periods (p < 0.05) as a result of greater slow wave and rapid eye movement sleep and lower fragmentation.Conclusions:
There were no observed differences in sleep quality corresponding to the type of ventilator used despite slight differences in patient–ventilator asynchrony. Noninvasive ventilation sessions did not prevent patients from sleeping; on the contrary, they seem to aid sleep when compared with unassisted breathing.