Neonatal
hyperbilirubinemia is an excess of bilirubin in the blood and it causes the
baby to look jaundiced. Phototherapy takes advantage of the effect that certain
wavelengths of light have on the bilirubin molecule.
Bilirubin
phototherapy can be successfully carried out both at the hospital or at home
depending on the seriousness of infant’s condition. Generally, babies require
several days of bilirubin phototherapy to help them break down excessive levels
of bilirubin. Adequate hydration with breast milk or formula is necessary as
part of the bilirubin phototherapy to excrete bilirubin pigment through urine
and stools and avoid dehydration due to exposure to the lights.
As soon as bilirubin levels return to normal levels, bilirubin
phototherapy is discontinued but bilirubin levels need to be continuously
monitored for the next few days.
All newborns undergoing bilirubin phototherapy must have their
temperature levels, as well as the color of their skin, closely monitored to
avoid overheating and skin burns.
Bilirubin phototherapy is overall considered a safe method that has
been used for many years to treat neonatal hyperbilirubinaemia. Sometimes
bilirubin phototherapy can cause mild but unfortunate side effects such as: skin
burns, rashes, excessive tanning and skin irritation. Changing the baby’s
position every so often during the light therapy is believed by some medical
experts to reduce the likelihood of skin irritation. Elimination of excessive
bilirubin levels from baby’s blood can cause diarrhea stools in babies, which
are considered normal and expected during neonatal jaundice recovery stage.
The range of light wavelength between 425 nanometers to 475
nanometers is considered as the best for neonatal phototherapy. It is common to
call it “blue light”. However, it contains violet components. Some recent
researches advocate the use of blue-green light.
Short waves, below 400 nanometers, should be avoided. If the source
generates these components, they should be blocked by a proper filter. Also, the
radiation of long light wavelengths should be reduced to minimize the baby’s
skin heating.
Phototherapy
equipment can be divided into two main categories. The first type consists
of a light unit which may be positioned above or below the baby. These units may
include blue or white lamps. This type of phototherapy has been on the market
for many years and is usually referred to as conventional phototherapy.
A newer development is the fiberoptic
form of phototherapy equipment. This type delivers light from a halogen bulb via
a fiberoptic cable to a pad containing woven optical fibers. This special
bilirubin phototherapy pad is placed next to the baby’s skin.
As the emitted light of the tube is filtered to remove the
ultraviolet and infrared bands, the pad is cool to the touch and may be directly
placed on the baby’s body (or through a transparent cover). This newer type has
been in use for around the last 10 years.
The area of the skin illuminated needs to be as large as possible, to
maximize the efficiency of the phototherapy. Many overhead devices can
illuminate up to one third of the infant’s skin. Methods using a light source
above and below the infant, termed double phototherapy, further increase the
area of skin irradiated.
Conventional phototherapy equipment is either in the form of a
Tungsten halogen spotlight, a metal halide gas discharge lamp or fluorescent
lamps. Spotlights typically have ultraviolet (UV) emissions filtered out in the
bulb housing to prevent unnecessary irradiation of the infant. Metal halide
discharge lamps were developed from mercury gas discharge lamps and are housed
in a canopy with separate UV filters. Fluorescent tube devices use a single tube
or a set of several tubes and again the light emission is filtered to reduce the
UV component to safe levels.
Source: http://www.medwow.com/articles/
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