Association Between Sleep and Functional Outcome in Critically Ill Patients

Objective Examine the association between sleep and clinical outcome in patients with acute brain injury and critical illness. Methods Retrospective analysis of critically ill patients who underwent continuous electroencephalography monitoring in an academic medical center from 2018-2020. Patients admitted with primary neurologic, medical, and surgical conditions were included. Clinical outcome was determined by the modified Rankin Scale (mRS < 3 represented favorable outcome). Statistical modeling of outcome included predictor variables controlling for anesthetic concentration, diagnosis, and sex. Results 262 patients were included of which 57% were male with a mean age of 58 years (range 18-91). Twenty-one percent of the total population achieved sleep (56/262). Of those achieving any sleep, 43% had good outcomes compared to only 26% who did not (χ² =10.99, p = 0.0009), controlling for diagnosis, sex, anesthetic level, and Acute Physiology and Chronic Health Evaluation score. Neurological patients attained sleep more often (27%) compared to those with other primary diagnoses (14%). In multivariable analysis, the effect of level of centrally acting anesthetics did not account for sleep differences between neurologic and non-neurological patients (χ² =3.5, p = 0.95). Conclusions Neurocritical patients slept more often, and obtaining any sleep was associated with better functional outcome when controlling disease severity. Further studies are needed to determine whether sleep augmentation and anesthetic use in critically ill patients impact functional outcomes.