Sleep in ICU: the role of environment

Boyko, Y. et al. Journal of Critical Care. Published online: 10 September 2016


Purpose: To determine if improving ICU environment would enhance sleep quality, assessed by polysomnography, in critically ill mechanically ventilated patients.

Materials and methods: Randomized controlled trial, cross-over design. The night intervention “Quiet routine” protocol was directed towards improving ICU environment between 10 pm and 6 am. Noise levels during control and intervention nights were recorded. Patients on mechanical ventilation and able to give consent were eligible for the study. We monitored sleep by PSG.2 sleep scoring criteria were insufficient for the assessment of polysomnograms. Modified classification for sleep scoring in critically ill patients, suggested by Watson, was used.

Results: Sound level analysis showed insignificant effect of the intervention on noise reduction (P = .3). The analysis of PSGs revealed that only 53% of the patients had identifiable characteristics of normal sleep, while 47% showed only pathologic patterns.

Conclusions: Characteristics of normal sleep were absent in many of the PSG recordings in these critically ill patients. We were not able to further reduce the already existing low noise levels in the ICU and did not find any association between the environmental intervention and the presence of normal sleep characteristics in the PSG.

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The association of sleep quality, delirium, and sedation status with daily participation in physical therapy in the ICU

Kamdar, B.B. et al. Critical Care. Published online: 18 August 2016
Image source: Tim Ellis – Wellcome Images // CC BY-NC-ND 4.0

Background: Poor sleep is common in the ICU setting and may represent a modifiable risk factor for patient participation in ICU-based physical therapy (PT) interventions. This study evaluates the association of perceived sleep quality, delirium, sedation, and other clinically important patient and ICU factors with participation in physical therapy (PT) interventions.

Method: This was a secondary analysis of a prospective observational study of sleep in a single academic medical ICU (MICU). Perceived sleep quality was assessed using the Richards-Campbell Sleep Questionnaire (RCSQ) and delirium was assessed using the Confusion Assessment Method for the ICU (CAM-ICU). Other covariates included demographics, pre-hospitalization ambulation status, ICU admission diagnosis, daily mechanical ventilation status, and daily administration of benzodiazepines and opioids via bolus and continuous infusion. Associations with participation in PT interventions were assessed among patients eligible for PT using a multinomial Markov model with robust variance estimates.

Results: Overall, 327 consecutive MICU patients completed ≥1 assessment of perceived sleep quality. After adjusting for all covariates, daily assessment of perceived sleep quality was not associated with transitioning to participate in PT the following day (relative risk ratio [RRR] 1.02, 95 % CI 0.96–1.07, p = 0.55). However, the following factors had significant negative associations with participating in subsequent PT interventions: delirium (RRR 0.58, 95 % CI 0.41–0.76, p <0.001), opioid boluses (RRR 0.68, 95 % CI 0.47–0.99, p = 0.04), and continuous sedation infusions (RRR 0.58, 95 % CI 0.40–0.85, p = 0.01). Additionally, in patients with delirium, benzodiazepine boluses further reduced participation in subsequent PT interventions (RRR 0.25, 95 % CI 0.13–0.50, p <0.001).

Conclusions: Perceived sleep quality was not associated with participation in PT interventions the following day. However, continuous sedation infusions, opioid boluses, and delirium, particularly when occurring with administration of benzodiazepine boluses, were negatively associated with subsequent PT interventions and represent important modifiable factors for increasing participation in ICU-based PT interventions.

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Lighting, sleep and circadian rhythm: An intervention study in the intensive care unit

Engwall, Fridh, Johansson, Bergbom & Lindahl
Journal of Intensive and Critical Care Nursing
December 2015 Volume 31, Issue 6, Pages 325–335
Patients in an intensive care unit (ICU) may risk disruption of their circadian rhythm. In an intervention research project a cycled lighting system was set up in an ICU room to support patients’ circadian rhythm. Part I aimed to compare experiences of the lighting environment in two rooms with different lighting environments by lighting experiences questionnaire. The results indicated differences in advantage for the patients in the intervention room (n = 48), in perception of daytime brightness (p = 0.004). In nighttime, greater lighting variation (p = 0.005) was found in the ordinary room (n = 52). Part II aimed to describe experiences of lighting in the room equipped with the cycled lighting environment. Patients (n = 19) were interviewed and the results were presented in categories: “A dynamic lighting environment”, “Impact of lighting on patients’ sleep”, “The impact of lighting/lights on circadian rhythm” and “The lighting calms”. Most had experiences from sleep disorders and half had nightmares/sights and circadian rhythm disruption. Nearly all were pleased with the cycled lighting environment, which together with daylight supported their circadian rhythm. In night’s actual lighting levels helped patients and staff to connect which engendered feelings of calm.