phototherapy in jaundice
TRANSCRIPT
Phototherapy for Jaundice
Sunil Kumar Daha
Phototherapy
• Goal: to treating neonatal hyperbilirubinemia and prevent related neurotoxicity
• Decreases the need for exchange transfusion• Exposure of the skin of the jaundiced baby to
blue or cool white light of wavelength 425-475 nm
• Toxic bilirubin molecule isomerizes to non-toxic product
Guidelines for Phototherapy
Suggested TSB cut-offs for phototherapy and exchange transfusion in preterm infants <35 weeks
Gestation (Completed weeks) Phototherapy Exchange Transfusion
<28 5-6 11-14
28 to 29 6-8 12-14
30 to 31 8-10 13-16
32 to 33 10-12 15-18
34 12-14 17-19
Guidelines for Phototherapy
Phototherapy• The mainstay of treating hyperbilirubinemia in
neonates• Acts by converting insoluble bilirubin
(unconjugated) into soluble isomers; excreted in urine and feces
• Uses blue- green light (460-490nm)• The product is harmless isomers • Acts only on bilirubin present in skin
Mechanism of Phototherapy
1. Configurational Isomerization
2. Structural Isomerization
3. Photo oxidation
Configurational isomerization
light
• Z-isomer E-isomer
• Reversible as it reaches bile duct.• Constitute about 25% of TSB (non-toxic), after
8-12 hrs.• Excreted slowly from body
Structural Isomerization
• Bilirubin Lumirubin
• This reaction is directly proportional to dose of phototherapy
• Coverts 2-6% of TSB, which is excreted rapidly from body
Photo oxidation
Minor reaction
Forms photo-products that are excreted in the
urine
Types of phototherapy lights
• Fluorescent lamps – Colors: Cool white, blue, green, blue-green or torquoise– Shapes: Straight, or U-shaped (CFL)
• Halogen bulbs• High Intensity Light Emitting Diodes (LED)• Fibro-optic lights
Maximizing efficacy of phototherapy
• A minimum level of 30 microW/cm^2/nm in 460-490 nm must be ensured
• Lamp should be changed if :– Lamps are flickering – Ends blackened– Irradiance falls below specified level
• Maximum surface area of baby should be exposed• Blocking of light by equipment is avoided• Avoid large diaper or eye patch, cap, tape, dressing etc.• Minimize interruption of phototherapy during feeding
sessions
Light should fall on baby perpendicularly if the baby is in incubator
Maximizing efficacy of phototherapy
Phototherapy
Administering Phototherapy
1. Make sure ambient room temperature is optimum 25°-28°C
2. Remove all clothes of baby except the diaper3. Cover the eyes with eye patches 4. Place naked baby under the lights– in a cot or bassinet: weight >2 kg or– in an incubator or radiant warmer: weight <2kg
5. Keep baby at a distance of 30-45 cm from light sources
6. Ensure optimum breastfeeding.
Monitoring and stopping phototherapy
• Monitor temperature every 2 – 4 hrs.• Measure TSB level every 12-24 hrs.• Discontinue - once two TSB values fall below age
specific cutoffs, twelve hours apart• Monitored for rebound bilirubin rise within 24 hrs.
after stopping phototherapy
References
Ghai Essential Pediatrics, 8th Edition
Nelson Textbook Pediatrics, 20th Edition
Up-to-date 21.2
http://
www.ncbi.nlm.nih.gov/pubmed/11722753
Thank You