16. Sleep Disruption in the ICU

Quick Recap

Miscellaneous / Cross-Cutting, new protocol. Companion to Delirium Screening & Management (Neurology System) and Pain Assessment & Sedation Strategy (Miscellaneous Topics) — addresses the ICU's disrupted sleep environment specifically as a modifiable target, with genuinely mixed individual-intervention evidence set against a clearer multicomponent-approach hierarchy.

1. Definition

Poor sleep is common in ICU patients, with environmental factors (noise, light, care-related interruptions) substantially reducing and fragmenting sleep. Sleep disturbance is mechanistically linked to delirium development, prolonged ICU stay, and increased mortality — the underlying rationale for treating sleep promotion as a genuine clinical target, not merely a comfort measure.

2. The Physiological Thresholds — Why Typical ICU Environments Are Genuinely Disruptive

Continuous noise exceeding 30dB(A), or peak noise above 45dB(A), can negatively affect sleep — thresholds substantially below what many ICU environments actually produce. Noise above 70dB(A) can cause vasoconstriction, increased heart rate, hypertension, and even arrhythmias — a genuine physiological, not merely subjective-comfort, consequence of a loud ICU environment.

Light exposure in the range of just 30-50 lux at the angle of gaze can delay the circadian clock, acutely suppress melatonin, and disrupt sleep structure directly — a remarkably low threshold, meaning even modest overnight lighting (far dimmer than typical care-delivery lighting) can meaningfully disrupt circadian synchronization.

3. Individual Interventions — Genuinely Conflicting Trial Results

This protocol treats the earplugs/eye mask literature honestly as a genuinely mixed evidence body, not a clearly established, uniformly effective intervention:

• Some RCTs found earplugs/eye masks improved sleep quality AND reduced delirium (e.g., a 2022 study associating the intervention with improved sleep quality and lower delirium screening scores)
• Other RCTs found no significant difference in delirium prevalence despite the intervention (e.g., a small Thai ICU study, n=17, found no significant RCSQ score or delirium prevalence difference between groups)
• A recent, well-conducted surgical ICU RCT (stopped early after a planned interim analysis met significance criteria) found a significantly higher sleep quality score with earplugs/eye masks (Richards-Campbell Sleep Questionnaire 64.5 vs. 47.3, p=0.0007) — but found NO significant difference in CAM-ICU delirium scores or patient satisfaction between groups — a genuinely important dissociation: the intervention clearly improved the sleep-quality measure it was designed to affect, without demonstrating the downstream delirium-reduction benefit often assumed to follow
• A systematic review explicitly describes this literature as containing "conflicting data on the effectiveness of earplugs and eye masks for sleep promotion in the ICU" — this protocol treats this honestly rather than presenting earplugs/eye masks as a uniformly proven delirium-prevention tool

4. Multicomponent Interventions — The Clearer, Better-Supported Approach

A network meta-analysis of non-pharmacological sleep interventions for delirium prevention in postoperative ICU patients found a clear hierarchy:

• Multicomponent interventions were the most effective versus usual care (RR 0.32, 95% CI 0.20-0.51) — substantially larger effect than any single intervention type
• Interventions targeting stress relief were next most effective (RR 0.60, 95% CI 0.41-0.89)
• Interventions targeting circadian rhythm showed similar effectiveness (RR 0.61, 95% CI 0.39-0.96) and specifically improved sleep quality (SMD approximately -0.9)

Practical implication: this protocol favors bundled, multicomponent sleep-promotion strategies over relying on a single intervention (like earplugs/eye masks alone) — consistent with the broader ABCDEF bundle philosophy already established in the Delirium Screening & Management protocol (Neurology System), where combined interventions consistently outperform any single component in isolation.

5. Practical Implementation — What a Bundled Approach Looks Like

Reported effective non-pharmacological interventions across the sleep-promotion literature include: earplugs, eye masks, massage, relaxation therapies, foot baths, music interventions, targeted nursing protocols, acupressure, and aromatherapy — a genuinely wide range of modalities, most textually described as "reported effective" in individual small studies rather than uniformly confirmed across rigorous trials.

A quality-improvement approach worth noting: a dedicated QI intervention targeting sleep and delirium in a surgical ICU (Tonna et al., Chest 2021) illustrates a real-world, structured implementation approach — combining environmental modification (noise/light reduction), care-clustering to minimize overnight interruptions, and structured protocols rather than a single isolated intervention.

An emerging, less-studied environmental factor: a retrospective cohort study examining whether room characteristics (presence of windows or doors) are associated with CAM-ICU-positive delirium status — an active area of investigation, not yet an established basis for room-assignment decisions, but illustrating growing interest in the physical ICU environment itself as a modifiable factor beyond noise/light alone.

6. Practical Synthesis

1. Recognize typical ICU noise/light levels substantially exceed the thresholds known to disrupt sleep and circadian rhythm — this is a physiological problem, not merely a comfort issue
2. Don't rely on earplugs/eye masks alone as a proven delirium-prevention strategy — the evidence for sleep-quality improvement is more consistent than the evidence for actual delirium reduction
3. Favor bundled, multicomponent sleep-promotion approaches (noise/light reduction, care clustering, relaxation techniques, and structured protocols together) over any single intervention in isolation, consistent with the network meta-analysis hierarchy
4. Integrate sleep promotion within the broader ABCDEF/delirium-prevention bundle (cross-reference Delirium Screening & Management, Neurology System) rather than treating it as a standalone initiative
5. Consider structural/environmental factors (noise reduction protocols, lighting control, room characteristics) as part of a comprehensive approach, recognizing this remains an evolving area of investigation

7. Consultation Matrix

8. Documentation & Medicolegal Checklist

• Sleep-promotion interventions offered/used documented as part of the delirium-prevention bundle
• Noise/light reduction measures and care-clustering practices documented at the unit-protocol level

9. Key Guidelines

• No single guideline mandates a specific sleep-promotion protocol; the broader ABCDEF bundle framework (cross-reference Delirium Screening & Management, Neurology System) provides the most authoritative structural context for incorporating sleep promotion

10. Landmark Evidence

11. Controversies

• The earplugs/eye mask literature genuinely conflicts across individual trials, with the most methodologically notable recent study finding real sleep-quality improvement but no demonstrated delirium-reduction benefit — this protocol treats "improves sleep quality" and "reduces delirium" as two distinct claims requiring separate evidentiary support, consistent with this library's broader practice of not assuming a proximate physiological improvement automatically confers the more distal clinical outcome benefit.
• Multicomponent interventions show a clearer, more consistent effect than any single intervention — this protocol treats this network meta-analysis finding as the more reliable current guidance, while acknowledging that isolating which specific components within a bundle drive the benefit remains difficult to determine from bundled-intervention trial designs.
• Room characteristics (windows/doors) as an independent delirium risk factor remain an early-stage, unconfirmed area of investigation — not yet a basis for clinical room-assignment decisions.

12. References

1. Effect of earplug/eye mask on sleep and delirium in intensive care patients. 2022.
2. The efficacy of earplugs and eye masks for delirium severity and sleep quality in patients undergoing coronary artery bypass grafting in cardiac intensive care units: A single-blind, randomised controlled trial. 2023.
3. The effect of sleep-oriented non-pharmacological interventions in preventing delirium: a systematic review of randomized controlled trials. 2025.
4. The Impact of Earplugs and Eye Masks on Sleep Quality in Surgical ICU Patients at Risk for Frequent Awakenings. Crit Care Med. 2021.
5. Impact of earplugs and eye mask on sleep in critically ill patients: a prospective randomized study. Crit Care. 2017.
6. Hu RF, Jiang XY, Hegadoren KM, Zhang YH. Effects of earplugs and eye masks combined with relaxing music on sleep, melatonin and cortisol levels in ICU patients: a randomized controlled trial. Crit Care. 2015;19:115.
7. Litton E, Carnegie V, Elliott R, Webb SA. The efficacy of earplugs as a sleep hygiene strategy for reducing delirium in the ICU: a systematic review and meta-analysis. Crit Care Med. 2016;44:992-999.
8. Tonna JE, Dalton A, Presson AP, et al. The Effect of a Quality Improvement Intervention on Sleep and Delirium in Critically Ill Patients in a Surgical ICU. Chest. 2021;160(3):899-908.
9. Weinhouse GL, Schwab RJ, Watson PL, et al. Bench-to-bedside review: delirium in ICU patients - importance of sleep deprivation. Crit Care. 2009;13:234.

See also: Delirium Screening & Management (Neurology System) for the broader ABCDEF bundle framework sleep promotion fits within; Pain Assessment & Sedation Strategy (Miscellaneous Topics) for the related sedation-minimization approach that also supports better sleep architecture.