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Phototherapy

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Phototherapy, Bilirubin Lights, Bili Lights

  • See Also
  1. Exchange Transfusion in Newborns
  2. Risk Score for Neonatal Hyperbilirubinemia
  3. Nonphysiologic Neonatal Jaundice
  4. Neonatal Jaundice
  5. Neonatal Bilirubin
  6. Acute Bilirubin Encephalopathy
  7. Chronic Bilirubin Encephalopathy (Kernicterus)
  8. Exchange Transfusion
  • Background
  1. Phototherapy indications are based on Gestational age and hours of life
  2. Phototherapy initiation and monitoring is based on Serum Bilirubin (not transcutaneous Bilirubin)
  3. Thresholds to start Phototherapy were increased in 2022 by AAP
  • Indications
  • AAP 2022 - Phototherapy in LOW risk TERM infants (>36 weeks and >2 kg, or >35 weeks and >2.5 kg)
  1. Background
    1. Use BiliTool or PediTools calculators for exact indication thresholds (thresholds here are rough estimates summarizing guidelines)
    2. Thresholds updated in AAP 2022 are considerably higher than prior thresholds for initiating Phototherapy
    3. The upper range reflects the indication for exchange transfusion (Escalate care to NICU when within 2 mg/dl of upper threshold)
  2. Gestational age 40 weeks - Thresholds
    1. Age 24 hours: >=13.0 mg/dl to 21.5 mg/dl
    2. Age 48 hours: >=17.0 mg/dl to 24.0 mg/dl
    3. Age 72 hours: >=19.5 mg/dl to 26.0 mg/dl
    4. Age 96 hours: >=21.5 mg/dl to 27.0 mg/dl
  3. Gestational age 38 weeks - Thresholds
    1. Age 24 hours: >=12.0 mg/dl to 21.5 mg/dl
    2. Age 48 hours: >=16.0 mg/dl to 24.0 mg/dl
    3. Age 72 hours: >=18.5 mg/dl to 26.0 mg/dl
    4. Age 96 hours: >=20.5 mg/dl to 27.0 mg/dl
  4. Gestational age 36 weeks - Thresholds
    1. Age 24 hours: >=11.0 mg/dl to 21.0 mg/dl
    2. Age 48 hours: >=14.5 mg/dl to 22.0 mg/dl
    3. Age 72 hours: >=17.5 mg/dl to 24.0 mg/dl
    4. Age 96 hours: >=19.5 mg/dl to 25.5 mg/dl
  5. References
    1. Kemper (2022) Pediatrics 150(3): e2022058859 [PubMed]
  • Indications
  • AAP 2022 - Phototherapy in HIGH risk TERM infants (>36 weeks and >2 kg, or >35 weeks and >2.5 kg)
  1. Background
    1. Use BiliTool or PediTools calculators for exact indication thresholds (thresholds here are rough estimates summarizing guidelines)
    2. Thresholds updated in AAP 2022 are considerably higher than prior thresholds for initiating Phototherapy
    3. High risk factors for neurotoxicity include Hemolysis (e.g. g6PD, Hemolytic Disease of the Newborn), Sepsis, instability, albumin <3 g/dl
    4. The upper range reflects the indication for exchange transfusion (Escalate care to NICU when within 2 mg/dl of upper threshold)
  2. Gestational age 38 to 40 weeks - Thresholds
    1. Age 24 hours: >=10.5 mg/dl to 17.5 mg/dl
    2. Age 48 hours: >=14.0 mg/dl to 20.0 mg/dl
    3. Age 72 hours: >=16.5 mg/dl to 22.0 mg/dl
    4. Age 96 hours: >=18.0 mg/dl to 23.5 mg/dl
  3. Gestational age 36 weeks - Thresholds
    1. Age 24 hours: >=9.5 mg/dl to 16.5 mg/dl
    2. Age 48 hours: >=12.5 mg/dl to 19.0 mg/dl
    3. Age 72 hours: >=15.5 mg/dl to 21.0 mg/dl
    4. Age 96 hours: >=17.0 mg/dl to 22.0 mg/dl
  4. References
    1. Kemper (2022) Pediatrics 150(3): e2022058859 [PubMed]
  1. Weight <1250 grams
    1. Uncomplicated: Total Bilirubin > 13 mg/dl
    2. Complicated: Total Bilirubin > 10 mg/dl
  2. Weight <1500 grams
    1. Uncomplicated: Total Bilirubin > 15 mg/dl
    2. Complicated: Total Bilirubin > 13 mg/dl
  3. Weight <2000 grams
    1. Uncomplicated: Total Bilirubin > 17 mg/dl
    2. Complicated: Total Bilirubin > 15 mg/dl
  4. Weight <2500 grams
    1. Uncomplicated: Total Bilirubin > 18 mg/dl
    2. Complicated: Total Bilirubin > 17 mg/dl
  5. Weight >2500 grams
    1. Uncomplicated: Total Bilirubin > 20 mg/dl
    2. Complicated: Total Bilirubin > 18 mg/dl
  • Monitoring
  • During intensive Phototherapy in hospital
  1. Monitor with Serum Bilirubin
    1. Do not use transcutaneous Bilirubin meter to monitor while on Phototherapy
    2. Indications for transfer to higher level of care for exchange transfusion
      1. Continue intensive Phototherapy while awaiting exchange transfusion
      2. Serum Bilirubin <=2 mg/dl below exchange transfusion threshold
      3. Signs of Acute Bilirubin Encephalopathy (regardless of Bilirubin level)
  2. Initial monitoring
    1. Anticipate total Serum Bilirubin decrease by 6-20%
    2. Total Bilirubin >25 mg/dl: Recheck every 2-3 hours
    3. Total Bilirubin 20-25 mg/dl: Recheck every 3-4 hours
    4. Total Bilirubin 14-20 mg/dl: Recheck every 4-5 hours
    5. Total Bilirubin <14 mg/dl: Stop Phototherapy and recheck Bilirubin within 24 hours
      1. Further hospital observation for repeat Serum Bilirubin is not needed
      2. Significant rebound Hyperbilirubinemia is rare
      3. Maisels (2002) Arch Pediatr Adolesc Med 156(7): 669-72 [PubMed]
  3. Later monitoring once Bilirubin level is trending downward
    1. Recheck Total Bilirubin every 8-12 hours
    2. May discontinue Phototherapy when total Serum Bilirubin is at least 2 mg/dl below initiation threshold for age
  • Contraindications
  1. Conjugated Hyperbilirubinemia
    1. Risk of bronze baby syndrome (see adverse effects)
  • Mechanism
  1. Bilirubin absorbs light
    1. Most sensitive to blue-green light (460 to 490 nm)
  2. Photoisomerization
    1. Converts 4Z,15Z Bilirubin (toxic) to 4Z,15E Bilirubin (Lumirubin)
    2. Converted unconjugated isomer (lumirubin) excreted in urine or stool bile without the need for conjugation
  • Technique
  1. Precautions
    1. Direct or indirect sunlight is NOT a reliable or safe alternative when Phototherapy is indicated
    2. Indications to transfer to NICU for exchange transfusion
      1. Total Serum Bilirubin within 2 mg/dl of exchange transfusion threshold
      2. Signs of Acute Bilirubin Encephalopathy
  2. Standard Phototherapy light configuration
    1. Conventional light source (halogen or fluorescent) or light emitting diode (LED)
    2. Four overhead centrally placed blue bulbs (F20T12/BB)
    3. Two daylight fluorescent bulbs on each side of infant
  3. Double Phototherapy light configuration
    1. Light configuration above and
    2. Fiber-optic pad (e.g. bili-blanket) beneath infant
  4. Intensive Phototherapy
    1. Includes blue-green light in the 460 to 490 nm spectrum
    2. Irradiance >= 30 Uw/cm2/nm
      1. Irradiance increases when lights are closer to infant
  5. Infant protocol
    1. Place each light 15-20 cm from newborn (except pad)
    2. Infant naked except for eye shields and diaper
  6. Feeding
    1. Encourage Breast Feeding during Phototherapy
    2. May interrupt Phototherapy for up to 30 minutes per feed to allow for Breast Feeding
    3. Supplemental feeding with formula or expressed Breast Milk indications
      1. Weight loss >10% from birth weight
      2. Decreased urine and stool output
  7. Concurrent Bilirubin monitoring
    1. Expect Serum Bilirubin level decrease of 0.5 mg/dl every hour in the first few hours of starting Phototherapy
      1. Evaluate for Hemolysis if Serum Bilirubin does not decrease as expected
    2. Formula fed: Anticipate 1-2 mg/dl decrease every 4-6 hours
    3. Breast fed: Anticipate 2-3 mg/dl decrease per day
    4. Discontinue Phototherapy when Bilirubin <15 mg/dl
  • Management
  • Home Phototherapy Indications
  1. Infant >38 weeks gestation
  2. Age >48 hours of life
  3. Clinically well infant
    1. Weight loss <10% from birth weight
    2. Adequate feeding
    3. Adequate stool and Urine Output per 24 hours for age
  4. No neurotoxicity risk factors
    1. See Severe Neonatal Hyperbilirubinemia Risk Factor
  5. No prior Phototherapy
  6. Total Serum Bilirubin <= 1 mg/dl (17.1 umol/L) above the Phototherapy threshold for age in hours
  7. LED Phototherapy unit is available for immediate use today at home
  8. Resources are available for child to undergo daily serum Total Bilirubin levels at home
  • Adverse Effects
  1. Loose stools
  2. Skin Rashes
  3. Overheating
  4. Dehydration
    1. Insensible water loss
    2. Diarrhea
  5. Electrolyte disturbance
    1. Hyponatremia
    2. Hypokalemia
  6. Chilling from exposure of infant
  7. Bronze baby syndrome
    1. Dark, grayish brown discoloration of skin
    2. May persist for months
    3. Associated with Conjugated Hyperbilirubinemia
  • Complications
  1. Seizure Risk
    1. Increased risk (esp. males) in 2 to 7 per 1000 newborns following Phototherapy
    2. Newman (2018) Pediatrics 142(4): e20180648 [PubMed]
    3. Maimburg (2016) Epilepsy Res 124: 67-72 [PubMed]
  2. Cancer Risk
    1. Leukemia, Renal Cancer and hepatic cancer risk: 1 in 10,000 newborns treated with Phototherapy
    2. Auger (2019) Int J Cancer 145(8): 2061-9 [PubMed]
    3. Digitale (2021) Pediatrics 148(5): e2021051033 [PubMed]
    4. Wickremasinghe (2016) Pediatrics 137(6): e20151353 [PubMed]
  • Efficacy
  1. Phototherapy decreases the need for Exchange Transfusion
  2. Phototherapy does not decrease KernicterusIncidence
  • Resources
  1. Bilirubin Tool
    1. https://bilitool.org
  2. PediTools
    1. https://peditools.org/bili2022/
  • References
  1. Behrman (2000) Nelson Pediatrics, Saunders, p. 518
  2. (2023) Am Fam Physician 107(6): 661-4 [PubMed]
  3. Kemper (2022) Pediatrics 150(3): e2022058859 [PubMed]
  4. Muchowski (2014) Am Fam Physician 89(11): 873-8 [PubMed]
  5. Par (2023) Am Fam Physician 107(5): 525-34 [PubMed]
  6. Porter (2002) Am Fam Physician 65:599-614 [PubMed]