How many hours a day is phototherapy typically provided for newborns?

Phototherapy Duration for Newborns with Jaundice

Intensive phototherapy for hyperbilirubinemia in newborns should be provided continuously (24 hours per day) until the total serum bilirubin (TSB) has declined to a safe level, with brief interruptions only for feeding and parent-infant bonding. 1, 2

Phototherapy Duration Guidelines

Standard Approach

• Continuous phototherapy is the standard of care for infants requiring treatment for hyperbilirubinemia
• Brief interruptions are acceptable for:
  • Feeding (breastfeeding or bottle-feeding)
  • Parent-infant bonding
  • Essential care activities

Duration Based on Severity

1. Severe hyperbilirubinemia (requiring "escalation of care"):

   • Truly continuous, uninterrupted phototherapy
   • TSB measurements every 2 hours until levels begin to decline 1

2. Moderate hyperbilirubinemia:

   • Continual phototherapy with minimal interruptions
   • TSB monitoring every 4-6 hours depending on initial levels 2

3. Mild hyperbilirubinemia:

   • Continual phototherapy with allowance for brief interruptions
   • TSB monitoring every 6-12 hours

Monitoring Effectiveness

• Effective phototherapy should produce a decline in TSB of >2 mg/dL within the first 4-6 hours 1, 2
• Expect a decrease of 6-20% of the initial bilirubin level in the first 24 hours 2
• TSB should be measured to verify efficacy after starting phototherapy, with frequency depending on initial levels:
  • Every 2-3 hours if TSB ≥25 mg/dL
  • Every 3-4 hours if TSB 20-25 mg/dL
  • Every 4-6 hours if TSB <20 mg/dL 2

When to Discontinue Phototherapy

Phototherapy can be discontinued when:

• TSB has declined by 2-4 mg/dL below the hour-specific threshold at which phototherapy was initiated 1, 2
• For infants readmitted after birth hospitalization, when TSB falls below 13-14 mg/dL 2

Follow-up After Discontinuation

• For high-risk infants (received phototherapy <48 hours of age, gestational age <38 weeks, positive direct antiglobulin test, or suspected hemolytic disease):

  • Measure TSB 8-12 hours after discontinuation
  • Additional measurement the following day 1, 2

• For other infants:

  • Follow-up TSB within 1-2 days after phototherapy discontinuation 1

Special Considerations

• Recent research suggests that an 18-hour continuous phototherapy course may be sufficient for jaundiced newborns without neurotoxicity risk factors 3
• Home phototherapy is an option for select infants with less severe hyperbilirubinemia, but still requires continuous application with the same principles as hospital-based therapy 1
• Changing the infant's position during phototherapy has not been shown to improve effectiveness and may place the infant at risk for unsafe sleep positions 1

Pitfalls to Avoid

1. Inadequate monitoring: Failure to check TSB levels at appropriate intervals can miss rising bilirubin levels despite phototherapy, which may indicate hemolysis requiring escalation of care

2. Premature discontinuation: Stopping phototherapy too early can lead to rebound hyperbilirubinemia

3. Excessive interruptions: While brief interruptions are acceptable, prolonged breaks reduce effectiveness and may lead to treatment failure

4. Inadequate irradiance: Ensure proper light intensity (minimum 30 μW·cm⁻²·nm⁻¹) and appropriate wavelength (460-490 nm) 2

5. Insufficient skin exposure: Maximum body surface area (35-80% of skin) should be exposed for optimal effect 2