Nighttime Sleep Duration Is Associated with Length of Stay Outcomes among Older Adult Survivors of Critical Illness

Background Older adults who required mechanical ventilation while in an intensive care unit (ICU) require adequate sleep throughout recovery from critical illness. Poor post-ICU sleep quality may contribute to worsening impairments in physical, cognitive, or psychological status after critical illness, known as post-ICU syndrome. Previous research has evaluated post-ICU sleep with qualitative or mixed methods (eg, interviews, questionnaires). We proposed measurement of sleep with actigraphy. We hypothesized that nighttime sleep is associated with length of stay (LOS). Objectives The aims of this study were to describe sleep quality of previously mechanically ventilated older adults recently transferred out of ICU and explore relationships between sleep duration and LOS outcomes. Methods We enrolled 30 older adults, 65 years and older, within 24 to 48 hours after ICU discharge. We collected actigraphy data on post-ICU sleep duration (total sleep time [TST]) and sleep fragmentation (wake time after sleep onset) over 2 consecutive nights. We explored associations between TST and LOS (in days) outcomes using multivariate regression. Results Subjects' mean TST was 7.55 ± 2.52 hours, and mean wake time after sleep onset was 2.26 ± 0.17 hours. In exploratory regression analyses, longer ICU LOS (β = 0.543, P <.001) and longer length of mechanical ventilation (β = 0.420, P =.028) were associated with greater post-ICU TST, after adjusting for potential confounding factors. Total sleep time was prospectively associated with total hospital LOS (β = 0.535, P <.001). Discussion Older ICU survivors demonstrate greater sleep duration and worse sleep fragmentation. Poor sleep may contribute to longer LOS, secondary to post-ICU syndrome and sequelae. We recommend nursing interventions to promote sleep consolidation throughout transitions of care in the acute post-ICU recovery period.