Background and aims: Venous oxygen saturation (SvO2) decreases in situations of impaired oxygen supply of tissues, even if there is no reduction in arterial oxygen saturation (SaO2; Andersen CC et al., Pediatrics 2017). Hence, our aim was to assess whether there is a difference in peripheral muscle SvO2 (pSvO2) and fractional oxygen extraction (pFOE) measured by near-infrared spectroscopy (NIRS) between preterm neonates with an early infection compared to those without an early infection during the first 36 hours of life.

Methods: We analysed secondary outcome parameters of a randomized controlled trial (Pichler G et al., Front Pediatr 2018) and included preterm neonates at risk of early infection, in whom NIRS measurement including peripheral venous occlusion was performed. Infection was diagnosed by clinical signs and a positive blood culture and/or C-reactive protein above the cut-off value (10mg/l). We measured peripheral muscle tissue oxygenation index (pTOI) using NIRO 200-NX (Hamamatsu Photonics, Hamamatsu City, Japan), calculated pFOE from pTOI and SaO2 and measured pSvO2 via venous occlusion method.

Results: We included 33 preterm neonates (gestational age 33.2±1.5 weeks of gestation; birth weight 2007±486g; m:w=20:13). Of these, five (15.2%) developed an infection. Peripheral SvO2 was significantly lower (49.3% versus 59.0%; p=0.018) and pFOE significantly higher (47.8 versus 38.8; p=0.026) in preterm neonates with an infection.

Conclusions: We found impaired pSvO2 and increased pFOE in preterm neonates with an early infection. Non-invasive measurement of these parameters is feasible and could be utilized for early detection of impaired peripheral oxygenation and (micro-)circulation in the future.

06 - NON-INVASIVE MEASUREMENT OF VENOUS OXYGEN SATURATION AS EARLY MARKER OF IMPAIRED OXYGEN SUPPLY IN PRETERM NEONATES