Cerebral oxygenation in newborn infants at risk

PhD ceremony: Ms. E.A. Verhagen, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Cerebral oxygenation in newborn infants at risk

Promotor(s): prof. A.F. Bos

Faculty: Medical Sciences

One of the main aims of present-day neonatology is the prevention of major neurodevelopmental problems due to brain damage. Perinatal and neonatal risk factors causing disturbed cerebral oxygenation may harm the integrity and development of the young preterm and ill term-born brain. Cerebral oxygenation can be assessed by means of near-infrared spectroscopy (NIRS). NIRS measures regional cerebral tissue oxygen saturation (rcSO2) and allows calculation of fractional tissue oxygen extraction (FTOE) by combining rcSO2 and arterial oxygen saturation (SpO2) values: FTOE=(SpO2-rcSO2)/SpO2.

The primary aim of this thesis was to determine the clinical value of monitoring cerebral oxygenation by means of NIRS. Our second aim was to determine the course of rcSO2 and FTOE during the first weeks after birth in newborn infants at risk of disturbed cerebral oxygenation. In a heterogeneous group of preterm infants we demonstrated a negative association between both low and high neonatal rcSO2 and FTOE, and neurodevelopmental outcome at 2-3 years of age. Overall, and in each single study, we found decreasing rcSO2 and increasing FTOE during the first two weeks after birth. We explained this by an increased cerebral metabolic rate resulting in lower cerebral oxygen saturation and higher extraction.

Our studies add to the current understanding that NIRS is potentially a useful clinical tool that reflects cerebral perfusion, helps to identify the pathophysiology of several perinatal and neonatal morbidities, and may contribute to the prediction of, and possibly help prevent adverse outcomes of preterm-born children. In this way, NIRS has added value to neonatology.