Impact of phototherapy on vasoactive mediators: NO and VEGF in the newborn

Aim: The objective of this study was to evaluate the effects of close and remote phototherapy on serum nitric oxide (NO) and vascular endothelial growth factor (VEGF) levels as well as on body temperature heart rate and blood pressure in neonates of different gestational ages. Patients and method: Term (gestational age ≥37 weeks) and preterm neonates (GA < 37 weeks) with hyperbilirubinemia requiring phototherapy were included in the study. All patients except for the ones in incubators were randomized to receive either close phototherapy (15 cm above the patient) or remote phototherapy (30-45 cm above patient). Body temperature, heart rate and blood pressure were measured before treatment, six hours into treatment and one hour after cessation of treatment. Blood samples for NO and VEGF measurements were also taken at the same times. Results: Sixty-one term newborns and 37 preterm newborns were included in the study. Patients were distributed into four groups according to the dose of treatment together with gestational age, i.e. term close and remote photoherapy groups (n = 29, n = 32, respectively), preterm close and remote photoherapy groups (n=10, n=27, respectively). Body temperature increased significantly with phototherapy in all groups but was not at hyperthermia level. Heart rate increased in all groups except for term newborns in the remote phototherapy group and blood pressure decreased in term infants but was unchanged in preterms. None of these changes were at the level of tachycardia or hypotension for a newborn. Phototherapy did not result in elevation of NO or VEGF levels. Conclusion: This study showed that in our group of patients close or remote phototherapy caused some body temperature, heart rate and blood pressure changes that were not clinically significant and did not result in increased levels of NO or VEGF, which are well known vasodilator mediators.