RT Journal Article SR Electronic T1 Long Term Acute Care Patients Weaning From Prolonged Mechanical Ventilation Maintain Circadian Rhythm JF Respiratory Care FD American Association for Respiratory Care SP respcare.02344 DO 10.4187/respcare.02344 A1 Dafna Koldobskiy A1 Montserrat Diaz-Abad A1 Steven M. Scharf A1 John Brown A1 Avelino C. Verceles YR 2013 UL http://rc.rcjournal.com/content/early/2013/09/11/respcare.02344.abstract AB Purpose: Circadian rhythm regulates many physiologic and immunologic processes. Disruption of these processes has been demonstrated in acutely ill, mechanically ventilated patients in the ICU setting. Light has not been studied as an entraining stimulus in the chronically mechanically ventilated patient. The purpose of this study was to determine the association of naturally occurring ambient light levels in a long term acute care (LTAC) hospital with circadian rhythm in patients recovering from critical illness and requiring prolonged mechanical ventilation (PMV). Methods: We performed a prospective observational study of 15 adult patients recovering from critical illness and receiving PMV and admitted to the ventilator weaning unit at a LTAC hospital. Demographic data were obtained from chart review. Light stimuli in each patient room were assessed using a photometer device placed at eye level. Circadian rhythm was assessed by wrist actigraphy. Cumulative data was obtained from each device for a 48 hour period, averaged into four hour intervals and analyzed. Results: Patients receiving PMV were obese (mean BMI 32.7 ± 10.3 kg/m2), predominantly female (73%), and had an average age of 63.1 ± 14.3 years. Light exposure to this cohort maintained diurnal variation (p<0.001) and was significantly different across time periods. Circadian rhythm, as represented by actigraphy, also maintained diurnal variation (p<0.001) and was in phase with light. Linear regression of movement and time demonstrated a moderate relationship between l ight and actigraphy (R2 = 0.56). Conclusion: Despite requiring continued high level care and a prolonged stay in a medical facility, patients recovering from critical illness and actively weaning from PMV maintain their circadian rhythm in phase with normal diurnal variations of light.