Tissue oxygenation monitoring in newborn infants at risk of circulatory failure

Seriously ill newborn infants admitted to the neonatal intensive care unit (NICU) are at high risk of developing organ damage as a result of impaired organ blood flow and therefore impaired tissue oxygen delivery. Currently, organ tissue oxygen delivery cannot be measured continuously. Due to the inability to continuously monitor and assess tissue oxygen delivery, the risk of over- and undertreatment of (in)adequate tissue oxygen delivery is high. A more direct continuous measurement of actual tissue oxygen delivery is needed to adequately guide therapeutic interventions aimed at timeously improving impaired tissue oxygen delivery in these newborn infants, in order to prevent organ damage and to improve short- and long-term outcome. Near-infrared spectroscopy (NIRS) is a non-invasive technique with which organ tissue oxygen delivery can be measured continuously. In this thesis, we assessed the additional clinical value of monitoring tissue oxygen supply of multiple organs using NIRS in the clinical management of seriously ill newborn infants admitted to the NICU. We found poor agreement between tissue oxygen delivery as measured by NIRS and tissue oxygen delivery as estimated by currently used techniques. Tissue oxygen delivery as measured by NIRS was associated with adverse intestinal outcome, while currently used techniques were not, in preterm infants with clinical sepsis. Our results suggest a possible additional value of NIRS as a noninvasive monitor in detecting critically low tissue oxygen delivery compared to available noninvasive methods