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