Disrupted sleep patterns and atypical electroencephalograms in children admitted to the pediatric intensive care unit: an observational cohort study

Purpose : To describe sleep (disruptions) in critically ill and non-critically ill hospitalized children, by comparing sleep parameters to reference ranges of healthy children. Methods: Observational cohort study in a tertiary, university children’s hospital. Twenty-five critically ill children with expected PICU stay ≥ 48 hours who underwent 24-hour polysomnography (PSG) and 120 non-critically ill children who underwent diagnostic PSG between May 2017 and June 2021 for suspected sleep disordered breathing (SDB) were included. In both groups, nighttime sleep parameters were determined and compared to age-specific reference ranges obtained from literature. Results: Among critically ill children, comparison to reference ranges showed reduced rapid-eye-movement (REM) sleep (24, 96%) and, in those with discernable non-REM stages, reduced non-REM 3 sleep (4 of 6, 67%). Median nighttime sleep accounted for 50.9% (interquartile range (IQR) 49.5–55.5) of total 24-hour sleep. Moreover, EEG abnormalities were prominent (19, 76%), including abundant slow-wave activity (9, 36%), lacking sleep spindles (6, 24%) and/or K-complexes (2, 8%) and abnormal background EEG with persistent theta and delta activity (2, 8%). In non-critically ill children with suspected SDB, comparison to reference ranges showed reductions in REM sleep (age ≤ 6 months), reduced mean sleep period duration (age ≥ 1 year), and low sleep efficiency and high awakening index in older children. Conclusions: Critically ill children exhibit disrupted sleep architecture, loss of day-night variation and atypical EEG. Non-critically ill children mainly exhibit fragmented and reduced sleep. These findings foster better understanding of how critical illness and the hospital environment affect sleep in children.