Vergleich des zerebralen oxygenierungsindex gemessen mittels nah-infrarot-spektroskopie mit der sauerstoffsättigung im bulbus jugularis bei kindern

We investigated whether near infrared spectroscopy (NIRS) is a satisfactory continuous non-invasive diagnostic tool for monitoring cerebral oxygenation in infants. New generations of NIRS devices, such as the NIRO 300 (Hamamatsu Photonics, Japan), use spatially resolved spectroscopy (SRS) not only to provide the usual measurements of changes in haemoglobin concentration, but also to allow calculation of a tissue oxygenation index (TOI) as an absolute term, independent of a tissue path length factor. We compared cerebral TOI measured by NIRS and, as the reference method, venous oxygen saturation in the jugular bulb (SjO₂) measured by co-oximetry (OSM3 Hemoximeter, Radiometer Copenhagen, Denmark) during elective cardiac catheterization of children with cyanotic and non-cyanotic congenital heart defects. We examined 60 infants (median age: 4.4 years, 0.1-16 years) admitted for cardiac catheterization because of cyanotic (n = 15) and non-cyanotic (n = 45) congenital heart defects. Cerebral TOI was compared to SjO₂ taken from the jugular bulb during cardiac catheterization. Linear regression analysis and Pearson's correlation coefficient were calculated. Patients were divided into two groups regarding body weight: below and above 10 kg. Simultaneously measured values for SjO ₂ (67.3 ± 9.8%, 40-84.1%) and cerebral TOI (65.7 ± 7.2%, 39-80%) showed a significant correlation (r = 0.72, p < 0.001). Correlation in the group of children under 10 kg body weight (n = 29) was even stronger (r = 0.81, p < 0.001), whereas correlation in children over 10 kg body weight was less satisfactory (r = 0.44, p < 0.05). The results demonstrate that cerebral tissue oxygenation index measured by NIRS provides reliable information concerning cerebral oxygenation, particularly in children with less than 10 kg body weight.