Is there an association between subjective sleep quality and daily delirium occurrence in critically ill adults? A post hoc analysis of a randomised controlled trial

Abstract

ObjectivesWhether and how delirium and sleep quality in the intensive care unit (ICU) are linked remains unclear. A recent randomised trial reported nocturnal low-dose dexmedetomidine (DEX) significantly reduces incident ICU delirium. Leeds Sleep Evaluation Questionnaire (LSEQ) scores were similar between intervention (DEX; n=50) and control (placebo (PLA); n=50) groups. We measured the association between morning LSEQ and delirium occurrence in the prior 24 hours (retrospective analysis) and the association between morning LSEQ and delirium occurrence in the following 24 hours (predictive analysis).DesignPost hoc analysis of randomised controlled trial data.ParticipantsAdult ICU patients (n=100) underwent delirium screening twice a day using the Intensive Care Delirium Screening Checklist (ICDSC) if Richmond Agitation Sedation Scale (RASS) was ≥−3 and patient-reported sleep quality evaluations at 09:00 daily with the LSEQ if RASS was ≥−1.OutcomesThe analysis included all 24-hour study periods with LSEQ documentation and matched delirium screening in coma-free patients. Separate logistic regression models controlling for age, baseline Acute Physiology and Chronic Health Evaluation II score and DEX/PLA allocation evaluated the association between morning LSEQ and delirium occurrence for both retrospective and predictive analyses.ResultsThe 100 patients spent 1115 24-hour periods in the ICU. Coma, delirium and no delirium occurred in 130 (11.7%), 114 (10.2%) and 871 (78.1%), respectively. In the retrospective analysis, when an LSEQ result was preceded by an ICDSC result (439/985 (44.6%) 24-hour periods), delirium occurred during 41/439 (9.3%) periods. On regression analysis, the LSEQ score had no relationship to prior delirium occurrence (OR (per every 1 point average LSEQ change) 0.97, 95% CI 0.72 to 1.31). For the predictive analysis, among the 387/985 (39.1%) 24-hour periods where an LSEQ result was followed by an ICDSC result, delirium occurred during 56/387 (14.5%) periods. On regression analysis, the LSEQ score did not predict subsequent delirium occurrence (OR (per 1 point LSEQ change) 1.02, 95% CI 0.99 to 1.05).ConclusionsThe sleep quality ICU patients perceive neither affects nor predicts delirium occurrence.Trial registration numberNCT01791296

Impact of a Pharmacist-Led Intensive Care Unit Sleep Improvement Protocol on Sleep Duration and Quality

“…25 Moreover, the relationship between sleep quality and delirium continues to be questioned. 26 Patient-perceived sleep quality using validated scales such as the RCSQ cannot be evaluated in patients who are sedated or have delirium. 5 Research-grade actigraphy and PSG each have unique limitations when they are used to measure sleep in the ICU (eg, expensive equipment often needing technician support and potential interference with routine patient care activities).…”

Characterization of Nocturnal Neuroactive Medication Use and Related Sleep Documentation in Critically Ill Adults

“…Sleep is frequently disrupted during critical illness; poor sleep is a common source of distress for patients ( 1 ). Delirium is also prevalent in the ICU and has been postulated to be both a cause and sequelae of disrupted sleep, although the inter-relationship between the two remains poorly researched ( 1 – 3 ). Polypharmacy is a common sequelae of ICU admissions and is associated with increased adverse events and costs ( 4 ).…”

The authors reply

“…We thank Lopez et al (1) for their letter and thoughtful comments on our recently published clinical investigation (2) in Critical Care Medicine , evaluating the impact of earplugs and eye masks on sleep quality in surgical ICU patients at risk for frequent awakenings. The relationship between sleep quality and ICU delirium has not yet been firmly established (3), and we acknowledge that interventions aimed at improving sleep quality may not reliably decrease the occurrence of delirium. We agree that future trials designed to further evaluate the interplay between critical illness, sleep, sedation, and delirium are needed to improve our understanding of this relationship.…”