Photo-Therapy Treatment For Jaundice in New Born Baby 

Rent Bili-Blanket in India for New Born Baby Jaundice Treatment

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August 16, 2016

Phototherapy Dose

The effectiveness of phototherapy at converting bilirubin into configurational isomers, structural isomers, and photooxidation products is determined by the dose of phototherapy provided to the infant. The dose of phototherapy depends on several factors, including the spectral wave length of light, the spectral irradiance delivered to the infant’s skin, and the total spectral power (average spectral irradiance delivered across the surface area of the infant). Factors that affect phototherapy are described in the image below.

Factors that affect phototherapy: The 3 factors thFactors that affect phototherapy: The 3 factors that affect the dose of phototherapy include the irradiance of light used, the distance from the light source, and the amount of skin exposed. Standard phototherapy is provided at an irradiance of 8-10 microwatts per square centimeter per nanometer (mW/cm2 per nm). Intensive phototherapy is provided at an irradiance of 30 mW/cm2 per nm or more (430–490 nm). For intensive phototherapy, an auxiliary light source should be placed under the infant. The auxiliary light source could include a fiber-optic pad, a light-emitting diode (LED) mattress, or a bank of special blue fluorescent tubes. Term and near-term infants should receive phototherapy in a bassinet and the light source should be brought as close as possible to the infant, typically within 10-15 cm. However, if halogen or tungsten lights are used, providers should follow the manufacturer recommendation on the distance of the light from the infant to avoid overheating. Preterm infant can be treated in an incubator, but the light rays from the phototherapy device should be perpendicular to the surface of the incubator to minimize light reflectance. Adapted from Maisel MJ, McDonagh AD. Phototherapy for Neonatal Jaundice. N Engl J Med. 2008;358:920-928.

Light in the blue region of the spectrum, near 460 nm, is most strongly absorbed by bilirubin. However, only light that penetrates the skin and is absorbed by bilirubin provides the needed photochemical effect. Tissue penetration increases as the wavelength of the light increases. Thus, one must balance the use of a higher wavelength of light, which more readily penetrates tissue, with the use of a wavelength that is more readily absorbed by bilirubin, which may penetrate less deeply. With this in mind, light in the 460-490 nm wavelength is probably the most effective for use during phototherapy.[1]

Spectral irradiance is measured in watts per centimeter, or microwatts per square centimeter per nanometer (mW/cm2 per nm) over a wavelength band. Higher spectral irradiance results in a more rapid decline in the bilirubin levels.[10] Spectral irradiance increases as the distance from the light source to the infant’s skin deceases.[6] Different phototherapy devices deliver significantly different levels of irradiance. The American Academy of Pediatrics defines standard phototherapy as 8-10 mW/cm2 per nm and intensive phototherapy as more than 30 mW/cm2 per nm in the 430-490 nm band.[6]

Spectral power increases as the amount of skin exposed to phototherapy increases. Ways to increase surface area exposure include removal of clothing and increasing the number of lights/lighting devices used to deliver phototherapy. Infants receiving phototherapy should be left only in their diaper, allowing adequate surface area exposure for phototherapy. The use of lights both above and below an infant effectively doubles the area of exposure. Several manufacturers produce fiberoptic pads that can be placed under the infant. The Bili Bassinet (Olympic Medical; Seattle, WA) is one commercial device that provides special blue fluorescent tubes that emit light in the 460-490 nm wavelength, both above and below the infant.

The dose of phototherapy, in mW/cm2 per nm, should be measured during phototherapy using a commercially available radiometer. These devices typically measure the spectral irradiance of phototherapy in the 425-475 or 400-480nm band wavelength. The radiometer used to measure irradiance should be the one recommended by manufacturer of the light source. Due to variance in the strength of phototherapy over the surface of the infant, and because measurements of spectral irradiance can differ greatly depending on where on the infant the measurement is made, taking several measures in different locations on the infant and averaging the values is important

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