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PhototherapyHow neonatal phototherapy works
Some devices use strong white-light sources that include significant output at the blue end of the spectrum. The use of these and mixed-light sources does not interfere with visual assesment of the neonate's colour and can prevent or alleviate the side effects of intense blue light on carers (e.g. headaches and nausea). However, they may have a reduced therapeutic effect compared to pure blue or blue-green sources.
Irradiance/light sources
The level of light output at different wavelengths is the spectrum of the source. Different light sources produce different shapes of light spectrum. For example, the fluorescent tubes used in various devices differ between manufacturers and therefore have different spectra. Irradiance values provide an indication of the 'strength' of the light and may represent a total light level over the 400-550nm range (blue to blue-green). However, direct comparisons between the irradiance values given by manufacturers are not generally possible due to different methods of measurement.
Heating
Phototherapy lamps may also act as a source of radiant heat to an infant. Halogen bulbs can produce a large amount of heat, blue fluorescent tubes produce less heat than white ones, and LED sources do not have a significant heating effect. Although a phototherapy lamp can be useful as supplementary heating, careful temperature monitoring and adjustment of any additional warming devices will be required to avoid overheating.
Treatment
Manufacturers state a minimum treatment distance for each device. It is important to treat as large a skin surface area as possible. However, as the source-to-mattress distance increases the illuminated area gets larger but the irradiance (strength) decreases.
Blue light is a hazard to the retina, so that an infant's eyes must be protected from direct phototherapy light. Most manufacturers of neonatal phototherapy devices also produce proprietary eye protection accessories. However, these are not specific to a light source and may be used interchangeably.
This page lists all the evaluation reports of blue light phototherapy units produced by CEDAR. Reports published after 2000 are available to view or download as high-quality PDFs. Prior to this printed copies of the earlier reports are being manually scanned and will be available as PDFs as they become available. Earlier reports may therefore be unclear in parts. Phototherapy reports
Market Survey: infant warming and phototherapy (update) (Report 06046) - September 2006 Market Survey: infant warming and phototherapy (Report 05103) - January 2006 This report includes devices other than phototherapy units and is listed on the page for every neonatal device-type. Natus neoBlue LED phototherapy system (MHRA 04143) - December 2004 Draeger Photo-Therapy 4000 Unit (MDA 01162) - December 2001 Medela Phototherapy Lamp (MDA 01161) - December 2001 Mediprema Cradle 360 (MDA 01160) - December 2001 Datex Ohmeda Spot Phototerhapy Lamp (MDA 00092) - May 2001 Hill-Rom Micro-Lite Phototherapy System (MDA 00091) - January 2001 Neonatal Phototherapy: A review (Evaluation 391) - April 2000
Last updated: 07/07/2009 |
Bilirubin is a by-product of the breakdown of red blood cells which is normally excreted by the liver. Neonates, and especially premature babies, may have livers that are not mature enough to perform this task adequately. Blood levels increase, resulting in hyperbilirubinaemia (neonatal jaundice). This is treated by phototherapy because light at blue or blue-green wavelengths converts the bilirubin molecule into a form that is either easier to excrete or is less toxic to the neonate. The effective spectrum for this process has been identified in vitro to peak at around 450nm (blue light). However, light with longer wavelengths (blue-green light) can penetrate further into the skin, so that these may be more therapeutic in vivo.
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