[Cerebral oxygenation and near-infrared rays spectrophotometry]

Near infrared spectroscopy (NIRS) is a new technique which allows non invasive bedside monitoring of cerebral oxygenation and hemodynamics by measuring relative changes in cerebral oxy- and deoxyhaemoglobin and cytochrome aa3. We have applied this technique to evaluate the possible effects on cerebral oxygenation and hemodynamics of clinical procedures usually performed on preterm infants:--endotracheal suctioning, and we have demonstrated that the magnitude and the duration of the negative effects of open system are significantly reduced using closed endotracheal suctioning system;--withdrawal and infusion through umbilical vein and artery cause significant changes in cerebral hemodynamics: these effects are significantly reduced after administration of ibuprofen;--treatment of patent ductus arteriosus with ibuprofen does not significantly reduce cerebral perfusion and oxygen availability compared to indomethacin and ibuprofen administration also does not affect cerebral vasoreactivity to arterial carbon dioxide tension;--administration of different types and doses of natural surfactant causes different changes in cerebral hemodynamics and these effects seem to be dose-related. Therefore NIRS is an useful device to investigate cerebral oxygenation state of preterm infants and new possibilities could derive from the introduction of a new NIRS method which allows to measure the tissue oxygenation index.