Tissue oxygenation monitoring in newborn infants at risk of circulatory failure
Seriously ill newborn infants who are 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 as a result impaired tissue oxygen delivery. Currently, organ tissue oxygen delivery cannot be measured continuously. This inability causes a high risk of over- and undertreatment of (in)adequate tissue oxygen delivery. 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 to continuously measure organ tissue oxygen delivery. 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 measured by NIRS, and tissue oxygen delivery estimated by currently used techniques. Tissue oxygen delivery 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.