Innovative ICU Solutions to Prevent and Reduce Delirium and Post–Intensive Care Unit Syndrome

Alawi Luetz, MD, PhD; Julius J. Grunow; Rudolf Mörgeli, MD; Max Rosenthal, MD, PhD; Steffen Weber-Carstens, MD, PhD; Bjoern Weiss; Claudia Spies, MD, PhD

Disclosures

Semin Respir Crit Care Med. 2019;40(5):673-686. 

In This Article

Complex Interventions

The authors of the Guidelines for the Prevention and Management of Pain, Agitation, Sedation, Delirium, Immobility, and Sleep Disruption explicitly issued a recommendation against single interventions, instead advocating multicomponent, nonpharmacological measures aiming at a reduction of risk factors for delirium, improving cognition, enhancing sleep, mobility, and reorientation. They also explicitly mention the minimization of light and noise to promote sleep.[13]

Conceptually, light interventions in the ICU should (1) minimize illuminance levels during the night to promote sleep but at the same time providing enough illuminance for orientation and simple tasks, (2) produce adequate E c levels at the patients' eye during the day for circadian entrainment but without entering the area of absolute glare, and (3) allow for specific sensory inputs to target specific symptoms or conditions of the patient (symptom-oriented treatment with light).

Beside interventions aimed at noise reduction, workflow, and infection control, Charité's new ICU room concept includes a newly developed light ceiling that combines all of the previously mentioned features. Each bed is equipped with an individual light-ceiling, extending from above the patient's head down to the patient's feet, covering an area of up to 6 m × 2.4 m. Two layers of light-emitting diodes (LEDs) make up the lighting device. The first layer consists of red, green, and blue (RGB) LEDs. The second layer comprises 3,456 white-light LEDs over an area of 1.8 m × 2.4 m. The second white-light-emitting layer allows the clinician to apply individualized dynamic-light therapy for circadian entrainment. The first experimental study[131] compared photometric parameters between the lighting equipment used in the study by Simons and colleagues (fluorescent tubes)[54] and Charité's new light-ceiling. The study results unveiled that only the large LED-based ceiling provided adequate illuminance and E c levels for MMS (Figure 2) without entering the area of absolute glare (Figure 3).

Figure 2.

Measured data of circadian effective irradiance (E c) for different types of lighting. The dashed line indicates the thresholds for maximal melatonin suppression for elderly adults 60 years and older (0.6 W m−2). Measurements were taken at patients' eye level. New LED ceiling, newly developed prototype at Charité University Hospital (see text). Fluorescent tubes, enabled for dynamic light application as used in the study by Simons et al.54 LED, light-emitting diodes.

Figure 3.

Measured data of luminance for different types of lighting. The dashed line indicates the thresholds for absolute glare (10,000 cd × m−2). Measurements were taken at patients' eye level. New LED ceiling, newly developed prototype at Charité University Hospital (see text). Fluorescent tubes, enabled for dynamic light application as used in the study by Simons et al.54 LED, light-emitting diodes.

The use of artificial lighting devices in medical therapy has opened up the field of light therapy to the use of targeted wavelengths to affect specific symptoms. This is to be regarded as an entirely different approach from targeted white light therapy which was the main topic of discussion so far.

The most well-studied effective wavelength is that of the green light spectrum. In experimental rat models, targeted green light exposure showed significant antinociceptive effects.[149] Green light has also been experimentally shown to induce rapid sleep onset, whereas blue light delayed sleep onset and increase glucocorticoid levels.[150]

Apart from wavelength-based light intervention, Charité's newly developed LED-ceiling allows for the expansion into various innovative future therapeutic models.

Historically, there have been data from the early 1980s suggesting that surgical patients with a hospital window view of a natural setting had shorter postoperative hospital stays and less analgesic requirements.[151] The visual content of the new LED-ceiling screen is based on a computational design approach. Moving colored shapes are visualized using RGB modules. As disorientation affects the majority of ICU patients, the sky is used as a basic layer which changes color based on the time of the day and depending on the geolocation. In terms of symptom diversity in critically-ill patients, different content layers have been developed to target the most frequent symptoms patients are suffering from (Figure 4).

Figure 4.

Visual content layers for nonpharamacological symptom-oriented treatment in intensive care unit patients.

To account for symptom complexity and the individual clinical condition of the patient as well, the developed software generates parameterized visualizations. Instead of playing back prerecorded animations, all visual content is driven by predefined parameters. These parameters include the results of routine pain, anxiety, sedation, and delirium monitoring with validated assessment tools like the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) or the Behavioral Pain Scale (BPS).[152]

The newly developed light-ceiling is only one of the elements used in Charité's multicomponent room intervention. The preliminary results of an observational cohort study revealed that the incidence of ICU delirium was significantly lower among patients treated in the modified rooms (46%) compared with patients treated in the standard rooms (76%).[153] Further analysis of the data might allow an estimation about which of the room interventions contributed to this clinical effect.

For a device or solution to become a complex intervention it must be used beyond the purposes for which it was initially provided. In this sense, a lighting device is not used merely for circadian entrainment but rather for cognitive stimulation, mobilization or weaning from mechanical ventilation. User interaction with a LED-ceiling, for example, through tablet software, can be used to provide cognitive training or simple games to stimulate the patient. This has been shown to improve cognitive performance in different contexts.[154]

The potential addition of an integrated movement sensor into the gaming interface could help promote mobility of patients outside of direct interventions by nursing staff or physiotherapists. Patients could target specific point on the ceiling or interact with a projection of natural surroundings. In these scenarios, a single device or room intervention connects to other elements within the environment in a way that makes a multicomponent concept even more effective.

One key challenge is the heterogeneity of the ICU population, which makes a "one-size-fits-all" solution unlikely to be useful. Therefore, developing specific environmental parameters that can be individualized to meet specific patient requirements might be a critical element for future research. The possibilities of such solutions, namely, to transform the patient environment into some active therapeutic agent, are promising and subject of further research.

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