Transepidermal water loss and cerebral hemodynamics in preterm infants: conventional versus LED phototherapy.

The aim of our study was to evaluate whether high-intensity gallium nitride light-emitting diode (LED) phototherapy (LPT) influences transepidermal water loss (TEWL) and cerebral hemodynamics in preterm neonates in comparison with conventional phototherapy (CPT). Thirty-one preterm infants were randomized for conventional (n = 14) and for LED (n = 17) phototherapy. All infants were studied using a Tewameter TM 210 and cerebral Doppler ultrasound immediately before phototherapy (time 0), 30 min (time 1), 1-6 h (time 2), and 12-24 h (time 3) after the start of phototherapy, and 6-12 h after discontinuing phototherapy (time 4). The study shows that LPT does not induce significant changes in TEWL (time 0: 2.75 +/- 4.71 ml/m(2)/h; time 3: 14.45 +/- 3.68 ml/m(2)/h), in peak systolic, end diastolic and mean cerebral blood flow velocity (CBFV), and in the resistence index (RI). On the contrary, CPT is associated with a significant increase of TEWL (time 0: 13.22 +/- 5.61 ml/m(2)/h; time 3: 20.94 +/- 3.21 ml/m(2)/h), which disappeared at time 4, when phototherapy had stopped. The peak systolic and mean CBFV increased, respectively, from 0.11 +/- 0.03 m/s at time 0 to 0.16 +/- 0.07 m/s at time 3. We conclude that LPT, emitting light within the 450-470-nm spectrum for optimal bilirubin degradation, can be preferable to CPT for the therapy of hyperbilirubinemia in preterm infants.