Multi-component environmental control intervention shows feasibility for sleep promotion in ventilated ICU patients

This pilot randomized controlled trial, conducted in an intensive care unit at a tertiary care teaching hospital in Santiago, Chile, was designed to assess the feasibility of implementing a multi-component environmental control intervention to promote sleep in critically ill, mechanically ventilated patients. The study enrolled 17 adult patients who had been mechanically ventilated for at least 48 hours and had received no or only superficial sedation in the preceding 24 hours. Participants were randomized to either the intervention group (n=9) or a standard care control group (n=8). The primary objective was to evaluate feasibility metrics, not to establish clinical efficacy.

The intervention consisted of three components: dynamic light therapy, auditory masking, and rationalization of nighttime care. Dynamic light therapy involved exposure to bright light during daytime hours and dim light at night. Auditory masking used white noise to dampen environmental sounds. Rationalization of nighttime care aimed to cluster nursing activities to minimize sleep disruptions. The comparator was standard ICU care, which did not include these structured environmental modifications. The intervention was delivered from randomization until ICU discharge.

The primary outcomes were feasibility measures. The enrollment rate was 94%. Retention until day three post-randomization was 78% in the intervention group (7 out of 9 patients) and 100% in the control group (8 out of 8 patients). Among the 8 intervention group participants who remained in the study until ICU discharge, all received the full intervention, indicating 100% fidelity. The 6-month post-ICU discharge follow-up rate was low at 35%. All participants who completed the study nights expressed very high satisfaction with the intervention.

Key secondary outcomes were intended to assess sleep quantity (via polysomnography and actigraphy), sleep quality (via the Richards-Campbell Sleep Questionnaire), prevalence of delirium at day three, and neuropsychological impairment at six months. However, the summary does not report any numerical results for these efficacy endpoints, as the study was not powered to detect differences and focused solely on feasibility. The absence of reported data on these secondary outcomes is a critical feature of this pilot study.

Safety and tolerability findings were not reported in the provided summary. There is no information on adverse events, serious adverse events, discontinuations due to the intervention, or general tolerability. This represents a significant gap in the available evidence from this study.

This pilot study cannot be directly compared to prior landmark efficacy trials in ICU sleep promotion or delirium prevention, as it was explicitly designed as a feasibility study. Larger randomized controlled trials, such as those testing pharmacologic sleep aids or other non-pharmacologic bundles, have reported on clinical outcomes like delirium incidence and ventilator-free days. This study's contribution is methodological, demonstrating that a complex environmental intervention can be implemented with high fidelity in a challenging ICU setting, which is a necessary precursor to a future definitive trial.

Key methodological limitations are inherent to its pilot and feasibility design. The sample size of 17 patients is very small. The study was not powered to detect differences in clinical outcomes like sleep architecture, delirium, or long-term cognitive function. The very low 6-month follow-up rate (35%) severely limits any assessment of long-term neuropsychological outcomes. The single-center setting in Chile may limit generalizability to other healthcare systems and ICU environments. The lack of reported safety data is another important limitation.

The clinical implication is that a multi-component environmental control intervention for sleep promotion is feasible to implement in a ventilated ICU population with minimal sedation. The high fidelity and participant satisfaction are encouraging for future research. For current practice, this study does not provide evidence to change clinical care, as it was not an efficacy trial. It does, however, provide a template for how such an intervention could be operationalized in an ICU setting.

Several important questions remain unanswered. The efficacy of this specific intervention bundle on objectively measured sleep quality and quantity is unknown. Its impact on short-term clinical outcomes like delirium prevalence or duration of mechanical ventilation is unknown. The long-term effect on neuropsychological function at 6 months post-ICU discharge could not be assessed due to high attrition. The safety profile and potential unintended consequences of the intervention components were not evaluated. Finally, the cost-effectiveness and resource requirements for implementing such an intervention on a larger scale are unclear. A fully powered, multicenter randomized controlled trial is required to answer these efficacy and safety questions.