Sleep-wake rhythms determined by actigraphy during in-hospital stay following discharge from an intensive care unit

Intermittent feeding and circadian rhythm in critical illness

PURPOSE OF REVIEW

Circadian rhythms, i.e., periodic oscillations in internal biological processes, modulate metabolic processes such as hormonal signalling, nutrient absorption, and xenobiotic detoxification. Meal timing is a strong entraining cue for peripheral clocks in various organs, and eating out of circadian phases can impair glucose, gastrointestinal, and muscle metabolism. Sleep/wake cycles and circadian rhythms are extremely disrupted during critical illness. Timing of nutritional support may help preserve circadian rhythms and improve post-Intensive Care Unit (ICU) recovery. This review summarises circadian disruptors during ICU admission and evaluates the potential benefits of intermittent feeding on metabolism and circadian rhythms.

RECENT FINDINGS

Rhythmic expression of core clock genes becomes rapidly disturbed during critical illness and remains disturbed for weeks. Intermittent, bolus, and cyclic enteral feeding have been directly compared to routine continuous feeding, yet no benefits on glycaemic control, gastrointestinal tolerance, and muscle mass have been observed and impacts of circadian clocks remain untested.

SUMMARY

Aligning timing of nutritional intake, physical activity, and/or medication with circadian rhythms are potential strategies to reset peripheral circadian rhythms and may enhance ICU recovery but is not proven beneficial yet. Therefore, selecting intermittent feeding over continuous feeding must be balanced against the pros and cons of clinical practice.

Factors Associated With Sleep Quality in Hospitalized Persons With Dementia

BACKGROUND

Factors associated with sleep quality have not been well examined in hospitalized older persons with dementia, who are at high risk for impaired sleep. The aim was to identify factors associated with sleep quality among hospitalized persons with dementia.

METHODS

This secondary analysis used baseline data from a cluster randomized trial. Factors examined included delirium severity, pain, depression, behavioral and psychological symptoms of dementia (BPSD), and daytime physical activity. Multiple stepwise linear regressions evaluated factors related to dimensions of sleep quality (sleep duration, efficiency, latency, and fragmentation; measured by the MotionWatch 8).

RESULTS

Increased daytime physical activity was associated with higher sleep duration [β=0.164; 95% confidence interval (CI), 0.111-0.717; P=0.008; 7.7% variance] and sleep efficiency (β=0.158; 95% CI, 0.020-0.147; P=0.010; 5.4% variance), and less sleep fragmentation (β=-0.223; 95% CI, -0.251 to -0.077; P<0.001; 10.4% variance). Higher BPSD was significantly associated with prolonged sleep latency (β=0.130; 95% CI, 0.098-2.748; P=0.035; 3.7% variance).

CONCLUSION

Results suggest the need to encourage daytime physical activity and reduce or manage BPSD to improve sleep quality among hospitalized persons with dementia.