ICU · Rehabilitation
Acute severe community-acquired pneumonia: ICU sleep disruption and circadian rhythm
Also known as Sleep in ICU · Circadian rhythm disruption · ICU environment · Sleep quality in critical illness · Sleep architecture in critical illness · Melatonin in ICU · Earplugs and eye masks in ICU · Cluster nursing care · Sleep-promotion protocol
Sleep disruption is near-universal in the ICU. Polysomnography of ventilated patients found NO patient with normal sleep: nocturnal sleep efficiency about 38%, stage 1 sleep up to 40% of total sleep time, REM reduced to about 10%, and arousals plus awakenings around 40 per hour. Causes: noise and patient-care activities (together under a third of arousals on PSG — the illness itself and its treatment account for the rest), light (even dim room light suppresses melatonin), medications (GABA-agonist sedation produces an absence of restorative sleep), and mechanical ventilation (over-assist causing hypocapnia and central apnoeas). Consequences: delirium (multicomponent sleep-promotion bundles reduce it), impaired glucose tolerance with raised evening cortisol and sympathetic activation, and persistent post-ICU sleep disturbance. Management: multicomponent bundle (cluster care, light/noise control, earplugs and eye masks) recommended by the 2018 PADIS guidelines; nocturnal melatonin reduces delirium on meta-analysis; dexmedetomidine improves sleep quantity and efficiency on PSG without eliminating REM.
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- Sleep promotion IS delirium prevention — an environmental sleep bundle cut delirium from 33% to 14% (Patel 2014)
- On PSG no ventilated ICU patient slept normally — night sleep efficiency about 38%, stage 1 up to 40% of sleep, REM about 10%
- Noise plus care activities explain under a third of arousals — but they are the most easily modified share; the illness and sedation do the rest
- Night-time light suppresses melatonin — even dim room light (about 100 lux) achieves roughly half of maximal suppression; ICU patients lose their nocturnal melatonin peak
- Propofol and midazolam produce an absence of restorative sleep — dexmedetomidine increases sleep efficiency and total sleep time on PSG without eliminating REM
- Patient-care activities disturb sleep about 8 times per hour — cluster care and protected sleep periods are the countermeasure
- Sleep disturbance PERSISTS after ICU discharge — 43% of survivors still report poor sleep at 12 months (post-intensive care syndrome)
Meet the patient
Day 3 of his septic-shock admission, your 72-year-old man is intubated for severe community-acquired pneumonia. He is CAM-ICU positive, and the night nurse reports he never slept — the unit is brightly lit (mean ICU illumination measured near 600 lux in Patel's series), monitor alarms fired all night, and he was woken repeatedly for bloods, repositioning, and medications — care activities disturb sleep about 8 times per hour in Gabor's PSG data. [4][3]
The trap on the round is to reach for more propofol. He is already deeply sedated, and GABA-agonist sedation produces an absence of restorative sleep rather than sleep itself. The fix is environmental before it is pharmacological: cluster the care, darken the bay, fit earplugs and an eye mask, tune the alarms, and switch toward dexmedetomidine. [17][4]
References22ShowHide
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