Patient ventilator discordance causes sleep disruption. Proportional assist ventilation seems more efficacious than pressure support ventilation in matching ventilatory requirements with ventilator assistance, therefore resulting in fewer patient-ventilator asynchronies and better quality of sleep.

In patients with chronic respiratory insufficiency, supine position was associated with worse sleep efficiency than the lateral decubitus position. AVAPS was comparable to NIV-PS therapy with regard to sleep, but statistically greater V(E) during AVAPS than NIV-PS of unclear significance was observed. V(E) was determined by sleep-wakefulness state, body mass index, and mode of therapy.

Reproducibility for spectral analysis of EEG was better than that for the manual methods: R&K methodology and sleep-wakefulness organization pattern. For assessment of sleep in critically ill patients, the use of spectral analysis, sleep-wakefulness organization state, or rapid eye movement sleep alone may be preferred over the R&K methodology.