From the Guidelines
Bilirubin levels should be rechecked every 2-3 hours for infants with severe hyperbilirubinemia (>20 mg/dL) and every 3-4 hours for those with moderate hyperbilirubinemia (20-25 mg/dL) during phototherapy treatment, as recommended by the most recent guidelines 1. The frequency of monitoring depends on the infant's initial bilirubin level, rate of rise, age, and risk factors.
- For infants with severe hyperbilirubinemia (>25 mg/dL), more frequent monitoring every 2-3 hours may be necessary, as suggested by the American Academy of Pediatrics guidelines 1.
- Once bilirubin levels show a consistent downward trend, testing can be extended to every 4-6 hours, and eventually to every 8-12 hours, as indicated by the infant's response to treatment 1.
- Phototherapy can typically be discontinued when bilirubin levels fall 2-4 mg/dL below the phototherapy threshold or reach a safe level (usually <13-14 mg/dL in term infants), as recommended by the latest technical report on phototherapy 1.
- A rebound check should be performed 8-12 hours after discontinuing phototherapy to ensure levels don't rise again, especially for infants who received phototherapy <48 hours of age, with a gestational age <38 weeks, with a positive direct antiglobulin test (DAT), or suspected of having hemolytic disease 1. This monitoring schedule is crucial because phototherapy works by converting bilirubin into water-soluble isomers that can be excreted without liver conjugation, and the effectiveness of treatment needs to be verified regularly to prevent bilirubin encephalopathy or kernicterus, as highlighted in recent clinical considerations 1.
From the Research
Bilirubin Level Recheck During Phototherapy
- The timing of rechecking bilirubin (bili) levels during phototherapy treatment is crucial to assess the effectiveness of the treatment and prevent potential complications 2.
- According to a study published in 2014, infants who were readmitted with high levels of bilirubin (more than 20 mg/dl) should be treated as an acute medical emergency, and phototherapy should be initiated within an hour of admission to prevent bilirubin encephalopathy 2.
- Another study published in 1982 suggested that phototherapy can be safely withheld until serum bilirubin exceeds 320 mumol/l, and the effect of early phototherapy on peak bilirubin level was not significant 3.
- A study published in 2009 found that transcutaneous bilirubin measurement using a multiwavelength transcutaneous bilirubinometer can be safely used to evaluate bilirubin levels in newborn infants under phototherapy, and its reliability on patched skin of the forehead is high enough to consistently reduce blood draws and to ascertain when to discontinue phototherapy 4.
- The frequency of rechecking bilirubin levels may vary depending on the individual case, but it is generally recommended to monitor bilirubin levels closely during phototherapy treatment to ensure that the levels are decreasing and to adjust the treatment as needed 5, 6.
- Some studies suggest that bilirubin levels should be rechecked after a certain period of phototherapy, such as 24 hours, to assess the response to treatment and adjust the intensity or duration of phototherapy accordingly 2, 3.