Sleep Quality, Circadian Rhythm Stability and Changes in Delirium State in Predicting Mortality Risk in Intensive Care Unit Patients: A Prospective Observational Study.
Hui-Ju Lai, Wen-Pei Chang
PMID 41243871WHAT IT FOUND
ICU patients with more fragmented sleep and less stable daily rhythms more often had delirium, and prolonged delirium was linked with higher six-month mortality.
These are associations, not proof that improving sleep prevents delirium.
Key findings
01Mortality was lowest among patients without delirium (13.3%) and highest among patients with prolonged (45.0%) or new-onset delirium (45.8%).
02Patients without delirium had less wake time after sleep onset than patients with prolonged or new-onset delirium; only the no delirium and prolonged delirium groups differed in circadian rhythm stability.
03When the researchers accounted for illness severity and other factors, prolonged delirium was associated with 3.92 times higher mortality risk than no delirium.
STILL TO COME
How it was doneWhat they foundWhat it means for RNs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
Only 74 patients from one medical centre in northern Taiwan were analysed, so the results may not apply to other ICU populations. The study was observational, so it cannot show that poor sleep or unstable circadian rhythm caused delirium or death. Patients expected to die within 72 hours, with brain damage-induced delirium, dementia, insomnia, severe sensory impairment, or inability to communicate were excluded. Actigraphy was used instead of polysomnography, and bedside window was only a rough proxy for light exposure. In adjusted survival analysis, only SOFA score and prolonged delirium remained linked to mortality; new-onset delirium, wake after sleep onset, and circadian stability were not. Sedative and analgesic use was recorded, but many medication variables were not significant, partly due to small sample size and dose variability.
Declared interests
The authors declared no conflicts of interest. The study was funded by the National Science and Technology Council.
The easy way to misread this
Do not conclude that reducing sleep fragmentation or stabilising circadian rhythms will lower delirium or mortality. This was an observational study of 74 ICU patients, and sleep variables were not independent mortality predictors after adjustment.