Effects of Nasal Airflow on Sleep in Tracheotomized Patients

Overview

The passage of air through the nasal cavities generates rhythmic oscillations transmitted by the olfactory bulb to the brain, which induces cerebral activation in functional brain areas and is associated with better cognitive performance compared to oral breathing. Consequently, the abolition of nasal ventilation - intrinsic in tracheotomized and ventilated patients - could have deleterious effects on brain activity. Besides the loss of olfaction, the abolition of nasal ventilation could affect brain activity and sleep. The hypothesis of the present study is that the restoration of nasal stimulation by the passage of humidified nasal airflow in tracheotomized and ventilated patients improves sleep quality, notably with a greater proportion of time spent in REM sleep.

The use of invasive mechanical ventilation via an endotracheal tube or tracheotomy involves bypassing the nasopharyngeal space and abolishing nasal ventilation. The first consequence is the loss of olfactory function. This function is quickly recovered when nasal ventilation is made possible. However, the abolition of nasal ventilation may have consequences beyond the loss of olfaction. The abolition of nasal ventilation in intubated rats inhibits these rhythmic oscillations, which can be restored by nasal sprays. In humans, nasal ventilation induces cerebral activity in functional brain areas and is associated with better cognitive performance compared to oral ventilation. In a model of intubated and ventilated rats, it has been shown that nasal sprays synchronized with the ventilator reduce hippocampal lesions compared to animals ventilated with an endotracheal tube without nasal sprays. Finally, in patients intubated with an endotracheal tube for toxic comas, the same nasal spray system restored brain activity and neural connectivity. The aim of this study is to test the effects of nasal airflow of the sleep in tracheostomized patients who are still dependent to invasive mechanical ventilation. Patients will be investigated by a full polysomnography during two consecutive nights, with and without nasal airflow on the top of invasive mechanical ventilation, the two nights being randomized.

Conditions