Life after intensive care unit: sleep and circadian health after a 12-month follow-up

Abstract

<b>Background:</b> Assessments to evaluate whether the effects of intensive care unit (ICU) on sleep and circadian health persist in the long term are scarce. <b>Objective:</b> To evaluate the sleep and circadian health of critical survivors after a 12-month follow-up. <b>Methods:</b> Prospective, observational study. Critical patients due to SARS-CoV-2 infection were recruited during the ICU stay. Clinical evaluations including the Pittsburgh Sleep Quality Index (PSQI) and actigraphy (7 days) were performed 3, 6, and 12 months after hospital discharge. <b>Results:</b> The cohort was composed of 230 patients (29.6% females), with a median [p25; p75] age of 62.0 [52.0;67.0] years. The median length of ICU stay was 12.0 [7.00;23.0] days, where 58.7% of the patients required invasive mechanical ventilation (IMV). According to the PSQI, 41.7% of the cohort presented poor sleep quality at the 12-month follow-up, demonstrating an improvement of 18.8% in relation to the 3-month follow-up. The high fragmentation of the rest-activity rhythm observed was similar to the previous assessments. Additional analyses revealed that female sex was associated with a decreased sleep quality at the 12-month follow-up (effect size [SD]: 0.346 [0.143]), whereas ICU stay duration (0.227 [0.094]), use of IMV (0.387 [0.204]), and IMV duration (0.178 [0.095]) were associated with increased fragmentation of the rhythm. <b>Conclusions:</b> Our findings reveal an improvement in the sleep quality of critical survivors, whereas the fragmentation of the rest-activity rhythm persists in the long term. This highlights the importance of considering circadian health after hospital discharge and addresses possible predictors for such outcome.