Objective: To determine changes in body temperature (BT) of hyperbilirubinemic newborns under conventional phototherapy with fluorescent lamps and light emitting diodes (LED) at different irradiances.
Methods: Otherwise healthy newborn infants >34 wk gestational age (GA) hospitalized for indirect hyperbilirubinemia, requiring phototherapy in the first 10 d of life were enrolled. Infants who received conventional phototherapy with fluorescent lamps (10-15 μW/cm(2)/nm irradiance) were defined as group 1, LED phototherapy of 26-60 μW/cm(2)/nm irradiance as group 2, and LED phototherapy of 60-120 μW/cm(2)/nm irradiance as group 3. Primary outcome measure was mean BT which was defined as arithmetical mean of axillary BT measured at 2 h intervals during the first day of phototherapy.
Results: Thirty patients were enroled in each group. Mean birth weight and GA of the total cohort was 2800 ± 530 g and 36.6 ± 2 wk, respectively. Baseline demographic variables and serum total bilirubin levels were similar among groups. Mean BT was 36.7 ± 0.1 °C in group 1, 36.6 ± 0.2 °C in group 2, 37.7 ± 0.2 °C in group 3. Mean BT was higher in group 3 compared to group 1 (p < 0.001) and group 2 (p < 0.001). Group 1 and group 2 had similar mean BT measurements (p = 0.09). During phototherapy all the patients in group 3 had at least one BT measurement ≥ 37.5 °C and 77 % had BT ≥ 38 °C. Only one patient in group 2 had BT ≥ 37.5 °C which was also ≥ 38 °C. During phototherapy all BT measurements were <37.5 °C in group 1.
Conclusions: LED phototherapy of ≥ 60 μW/cm(2)/nm intensity significantly increases BT in hyperbilirubinemic newborns.