In many ways the old saying “do unto others as you would like them to do unto you” is relevant to the topic of LED lighting in hospitals.
There are several opinions relating to the necessity of medical grade lighting in specific applications within hospitals. At the start of this article, acknowledgement is given that there are many hospitals in South Africa that have good lighting, that comply with the regulations and have indeed opted to procure the correct light fittings that have the patient and healthcare workers in mind.
In recent surveys that have been done in several hospitals in South Africa both in private and government sectors, lighting seems to be neglected and allowed to depreciate far below the minimum SANS standards set for health care facilities. Some private hospitals (names not mentioned intentionally) were found to be >90% non-compliant. This non-compliance included wards, passages, ICU, treatment rooms, ablutions, consulting rooms, back of house and administration. The purpose of this article is not to discuss the compliance levels, but rather to emphasize the necessity of proper, application specific lighting and maintaining the required standards for lighting as set out in the SANS regulations. Further this article will discuss the considerations to use medical grade COI lighting in HealthCare facilities. Eyes need three parameters which are the observer, the illuminant of a light source and the reflectance spectral of the object viewed to see colours.
The question is whether anyone would be satisfied by being treated in a healthcare facility that has insufficient lighting? I'm sure that given the option, no one would opt to be treated in a hospital with non-compliant lighting.
Further this article will highlight that compliant LUX levels may provide the impression of quality lighting; however, this may not be the case. Lux levels are only one of the considerations for hospital lighting. It is often said that hospitals are the expression of the sate of a nation. Trying to understand why the lighting standards are depreciating within our healthcare facilities some key contributors are highlighted below. The first and most obvious reason behind this is economic in its nature. Maintaining hospitals is a hugely expensive task and inevitably budgets are always under pressure resulting in the procurement of low-cost LED lighting. After all, a light is a light... Right? Not so!! Low-cost LED's can lose up to 30% of the lumen output within the first 1000 hours, resulting in non-compliance within a noticeably short period from installation. Cheap LED panels with inferior components will often turn yellow leaving hospital management embarrassed and all stakeholders from patients to owners criticizing the lighting within the hospital.
Secondly, it can often be observed that hospitals have a wide spectrum of colour temperatures installed. In a recent visit to a hospital, lighting with a CCT of 3000k and up to 8000k were observed in the same room. This is mainly due to either the lack of availability of similar / same CCT fixtures or the lack of standards / specifications that are being adhered to. Often maintenance teams are tasked to maintain and replace light fittings, that possibly were supplied by lighting suppliers without the express kowledge of hospital lighting, or simply purchased " over the counter". Hospitals often become the "smartie box" of lighting fixtures.
Should lighting designed for commercial offices be used in Hospitals?
The obvious answer to this question is that lighting designed for commercial officers can be used in hospitals however commercial lighting is not suitable for the treatment of patients. Commercial lighting can be installed in areas like passages, storerooms, administration blocks, reception, restaurants, waiting rooms, and other common areas. For areas such as emergency wards, recovery wards, ICU, treatment rooms, pre and post op, and the like, lighting with an improved spectral wavelength should be considered. No matter a person's ethnic background, skin colour or race, humans are all RED under the epidermis. Our blood and flesh is by and large, red in colour. Typically LED lighting has a very poor R9 (Red) wavelength. Compare the wavelength spectrums of the two images below. Specifically, compare R9 (RED)
Visual observation is the first method of diagnosis that is applied by medical practitioners. Therefore, a facility that is treating patients with open wounds, infections, etc should be procuring lights that have been designed with a specific spectral wavelength at 660 nM. One important aspect of clinical observation is the reliable detection of cyanosis, that is, the bluish discoloration in the skin and mucous membranes, which indicates that oxygen levels in the blood are dangerously depleted. Cyanosis detection can be impacted by a variety of variables, including room lighting and natural skin pigment.
We observe colour by reflection of light from objects. In simple terms an object is blue because it absorbs all the non-blue light and reflects the blue light back to our eyes. If the light source in the area has no blue component in its spectrum, then we will not detect the blue colour. The future of lighting is now firmly with light emitting diode (LED) technology. LEDs are more efficient than fluorescent sources and have advantages of compactness and no warm-up time. There are a number of white LED products available that have a COI that easily complies with the standards for observation of Cyanosis. Consequently, there has been a renewed interest in the COI as an appropriate and achievable measure in hospital lighting.
The use of pulse oximeters has minimized the need for the visual recognition of cyanosis. However, there are times when this is still valuable. Lighting is important for this visual task and it is also a difficult task for some people with colour vision deficiencies. Whilst there are numerous hospitals in South Africa that have embraced this technology, most hospitals are using LED light fittings that are not suitable for the visual diagnosis and detection of cyanosis. Many of our government hospitals do not have the use of pulse oximeters and in fact have not refurbished their lighting for several decades. This results in patients potentially being misdiagnosed or incorrectly treated resulting in an extended occupation of a bed within a ward or hospital. The compound impact of this is the inability to service the public in general due to a lack of beds, and additional expenses that may be incurred as a result of misdiagnosis. Historically, there were fluorescent tubes that permitted the accurate recognition of cyanosis but they used less efficient halophosphate technology. In the 1990s the change in fluorescent tube technology to give greater energy efficiency introduced tri-phosphor technology. This created some problems most notably for anesthetists. It has also been found that lamps suitable for the reliable detection of cyanosis should have a correlated colour temperature (CCT) between 3200 K and 5000k. In general it would be expected that non complying lamps with CCTs above 3200 K would provide false positive diagnoses and that lamps with CCTs below 3200 K would result in failure to detect cyanosis. It should be noted that, while cyanosis is defined as a bluish discoloration, 660 nm lies in the red end of the colour spectrum. In general it would be expected that Non complying lamps with CCTs above 3200 K would provide false positive diagnoses and that lamps with CCTs below 3200 K would result in failure to detect cyanosis. It should be noted that, while cyanosis is defined as a bluish discoloration, 660 nm lies in the red end of the colour spectrum.
For a light source to be suitable for the visual diagnoses of Hypoxia / Cyanosis, a CRI (Colour rendering index) should be greater than 93. CRI>93 Thus, the criteria for medial grade lighting are: 1. COI<3.3
2. CRI> 93
3. CCT:Between 3200k ~ 5000k
Mucous membranes and/or skin take on a bluish tint in cyanosis. There are other reasons why people develop bluish skin color, though this is most frequently due to an increase in the amount of deoxyhemoglobin (unoxygenated hemoglobin) in the vasculature.
The system transfer function of the epidermis, HbO2, Hb, dermis and hypodermis are labelled as HEpi, HHb02, HHb, HDermis and
Hypodermis, respectively.
IIn is referred to incoming light while Ray 1, Ray 2 and Ray 3 are the output rays of the light coming out from the skin.
As observed from the block diagrams, there are three different output rays can explain the light paths in the human’s skin.
Having spent several years researching correct technology Genesis One Lighting introduced COI LED lighting to the South African market. Having specialised in hospitals for many years, Genesis One Lighting is positioned to support, advise and supply the right solutions for healthcare facilities.
www.genesisonelighting,com
sales@genesisone.co.za
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