Assessment of Sleep in Patients Receiving Invasive Mechanical Ventilation in a Specialized Weaning Unit.

INTRODUCTION

A restful sleep is essential for regenerative processes and remains crucial for patients recovering from stressful periods in the intensive care unit. The current study aimed to assess sleep quality in critically ill patients receiving invasive mechanical ventilation within a specialized weaning unit in hospital.

METHODS

Tracheotomized subjects undergoing prolonged weaning from mechanical ventilation were included in the study. Polysomnography and gas exchange monitoring was performed during nocturnal ventilation. Subjective evaluation of sleep quality and health-related quality of life were also assessed.

RESULTS

Nineteen subjects completed the study protocol. Sleep architecture was highly heterogeneous across individual subjects. Mean total sleep time (TST) was 273 ± 114 min, sleep efficacy 70 ± 23%, slow-wave sleep 25.7 ± 18.4%/TST, rapid eye movement sleep 9.6 ± 7.5%/TST, and arousal index 18.7 ± 12.4/h. No significant difference in sleep quality was found between subjects with successful (N = 7) or unsuccessful (N = 12) weaning. Bicarbonate levels were negatively correlated both with sleep efficacy and sleep quality, that latter of which was subjectively assessed by the subjects using a visual analogue scale.

CONCLUSION

Subjects who were undergoing prolonged weaning from mechanical ventilation and admitted to a specialized weaning unit, showed reduced sleep quality with preservation of high amounts of slow-wave sleep.