TOPIC: Sleep Disorders TYPE: Late Breaking PURPOSE: Polysomnography is cumbersome and impractical for sleep assessment in centers that specialize in weaning from prolonged mechanical ventilation. It is unknown whether surrogate measures of sleep – namely actigraphy, which monitors gross motor activity, or behavioral assessment by a bedside nurse – could serve as reliable surrogates for the reference-standard of polysomnography in such patients. We hypothesized that actigraphy provides accurate estimates of sleep duration and disruption in this setting. METHODS: In 26 patients undergoing weaning from prolonged mechanical ventilation, we performed 12-hour overnight polysomnography with simultaneous dual-limb actigraphy. In addition, at the end-of-shift, the bedside nurse documented their assessment of the patient’s sleep. RESULTS: The median duration of mechanical ventilation was 33.5 days at the time of sleep assessment. The median sleep time recorded by polysomnography was 4.5 (interquartile range, 2.8 - 6.6) hours, while the corresponding values estimated by dual-limb actigraphy and by behavioral assessment were 7.7 (6.1 - 8.9) hours and 6 (5 -7.8) hours, respectively. Median number of awakenings during the sleep period by polysomnography were 43 (28 – 55.5), the corresponding values estimated by actigraphy and by behavioral assessment were 77.5 (49.5 – 99.5) and 3 (2 – 4.8), respectively. Sleep efficiency by polysomnography was 41.2% (23.8 - 55.8%) and 66.05% (46.2 – 74.83%) by actigraphy. Dual-limb actigraphy overestimated sleep efficiency in 22 patients, on average, by 28.48% and underestimated sleep efficiency in four patients, on average, by 13.38%. There was no correlation between actigraphic and polysomnographic assessments of sleep time, sleep efficiency and number of awakenings. There was also no correlation between behavioral and polysomnographic assessments of number of awakenings or total sleep time. CONCLUSIONS: Actigraphy and behavioral assessments of sleep were inaccurate and unreliable in quantifying sleep in patients receiving mechanical ventilation in a chronic weaning facility. CLINICAL IMPLICATIONS: Polysomnography remains the reference standard for sleep assessment in patients weaning from prolonged mechanical ventilation. DISCLOSURES: No relevant relationships by Swetha Gogineni, source=Web Response No relevant relationships by Franco Laghi, source=Web Response No relevant relationships by Hameeda Shaikh, source=Web Response