Donneborg ML, et al. – In this present study, the clinicians explored the impact of hemoglobin on the efficacy of phototherapy in hyperbilirubinemic infants. They reported that increasing hemoglobin levels were associated with a decrease in the efficacy of phototherapy. These findings suggested that the transformation of bilirubin to photobilirubins takes place mainly in the superficial capillaries of the skin.

Methods

• This trial consisted of 93 infants, gestational age ≥33 weeks, with uncomplicated hyperbilirubinemia.
• With LED light for 24 h, the infants were treated with conventional phototherapy.
• The median light irradiance was 66.8 μW/cm²/nm.

Results

• The median decrease in TsB after 24 h was 121 (57–199) μmol/l.
• The median hemoglobin was 12.0 (7.0–14.7) mmol/l. 
• There was a significant effect of hemoglobin concentration on the decrease in TsB of -3.61 μmol/mmol hemoglobin (P=0.022), after adjusting for initial TsB and postnatal age.
• That is, assuming the same initial TsB and postnatal age, for each mmol/l increase in hemoglobin, the decrease in TsB was 3.61 μmol/l smaller.
• In the hemoglobin range, the decrease in TsB was reduced by 28 μmol/l (23%).