I contributed this application article to the August issue of tED Magazine, the official publication of the NAED. Reprinted with permission.
Americans receive healthcare in more than 10,000 inpatient healthcare buildings in the United States, representing about 2.4 billion sq.ft., according to the 2012 U.S. Commercial Buildings Energy Consumption Study.
In these buildings, one of the most important spaces is the patient room, serving multiple functions related to both effective caregiving and patient recovery and comfort. Multiple studies demonstrated that well-designed rooms can increase patient satisfaction and reduce accidents, infection, stays, and pain medication, ideas that now drive mainstream patient room design.
This article introduces basic lighting design principles for patient rooms and then dives into new thinking such as circadian lighting. It is based on the Illuminating Engineering Society’s (IES) ANSI/IES RP-29-16, Lighting for Hospitals and Healthcare Facilities, and the Lighting Research Center’s Lighting Patterns for Healthy Buildings website.
Patient room lighting
Patient rooms are multifunctional spaces, including tasks ranging from sleep to cleaning, requiring a flexible lighting design. The first step is to divide the room into zones, typically patient, caregiver, and family. To serve these zones, the lighting system should be layered to provide ambient, accent, and task (exam) lighting. To address variation of lighting needs in each zone, these layers should be separately controlled, with further zoning based on need. Dimming or multilevel controls are recommended, with the patient having control of patient zone lighting from the bed. All controls should have proper indicators or otherwise be properly labeled.
Higher light levels are appropriate during the day than at night. Daylight is highly desirable. In multi-patient rooms, the designer must provide dedicated lighting to each patient, noting ceiling curtain tracks that may divide the room. At night, night lighting should be provided allowing safe travel to the bathroom, while sufficient light should be provided for caregivers. At night, caregiver light levels can be lower than during the day, as their eyes are considered adapted for lower light levels. Still, it can be challenging to design illumination that both facilitates sleep and staff work.
Generally, designers should put comfort first by avoiding sources of direct and reflected glare on room surfaces, TV screens, and personal electronic devices. Overall, the design should facilitate relaxation, while giving the patient as much control over their environment as possible. In some cases, a residential touch such as wall sconces can make patients feel more at home.
In the patient zone, lighting should be provided with an understanding many patients spend much of their time lying on a bed reading or watching TV, with the most critically ill sometimes having only the ceiling above as their view. Patient ambient lighting may be controlled at both the entrance and patient controls, such as a pillow speaker handheld and integrated bed control. Similarly, the patient will be given a personally controllable reading light. Patient examination is often illuminated by downlights with control conveniently accessed by the caregiver.
The above recommendations are for general patient room lighting. Note there are many specialized room types, such as airborne-infection isolation rooms, protective environment (PE) rooms, critical care, obstetrical care, nursery, neonatal intensive-care, pediatric, geriatric extended-stay, and psychiatric rooms. Each will have particular lighting needs. In pediatric patient rooms, for example, the finishes are often more colorful and playful, and family members typically remain with the patient throughout their stay. Consult IES-RP-29-16 for more information about lighting design considerations for these spaces.
Circadian lighting
The relationship between light and circadian response is becoming increasingly understood, resulting in new design considerations. These considerations are particularly important in healthcare environments, where facilitating healthy sleep is important. In its recommended practice for healthcare lighting design, the IES states, “Increasingly, facilities recognize the need for 24-hour circadian rhythm-supportive lighting schemes.”
The key factors in circadian entrainment are intensity (amount of light falling on eye’s photoreceptors, requiring vertical lighting), spectrum (wavelength of the light, commonly associated with correlated color temperature), timing (when light falls on the eye), and duration (the cumulative amount of light exposure during the day).
The Lighting Research Center (LRC) has conducted a significant amount of research in this area and produced a metric and recommendations. The metric is circadian stimulus, or CS, with 0.1 being the threshold for circadian response and 0.7 being the saturation point, and with 0.3+ recommended for at least one hour in the early part of the day. The recommendations can be found at LightingPatternsforHealthyBuildings.org.
In patient rooms, LRC recommends a high CS during the day and a low CS in the evening. As an example, in a single-patient room, one option is to install recessed linear luminaires, a wall-mounted direct/indirect task light over the bed, a few downlights at the entrance and perimeter, and a recessed linear wallwasher, with all luminaires fitted with LED sources.
During the day, the linear light, task light, and wallwasher dim over the course of the day until reaching 25 percent of full output in the evening. The downlights remain at full output during most of the day until dimming to 50 percent in the evening. All lighting adjusts from 5000K in the morning to 3000K midday and 3500K in the late afternoon and evening. Alternately, the wallwasher could tune to a saturated blue light. LRC calculated that this design would provide a stimulating 0.3 CS in the morning, adjust to 0.2 midday, and decline to 0.1 in the late afternoon and evening.
Patient room lighting
Patient rooms are a highly sensitive application demanding extraordinary functionality, comfort, and flexibility. As such, lighting designs must accommodate these customer demands. For help, some manufacturers produce specialized product lines around healthcare environments and offer deep application expertise.
Hunterdon Healthcare Cardiac Expansion, designed by Nadaskay Kopelson Architects. Photo by Halkin|Mason Photography. Image courtesy of Visa Lighting.
Below is a dual-occupancy patient room lighted for optimal circadian entrainment in the morning (top), afternoon (middle), and evening (bottom). Image courtesy of the Lighting Research Center.
You must be logged in to post a comment.