Abstract
IntroductionAdequate oxygen supply for preterm neonates may be defined through non-invasive measurement of venous oxygen saturation (SvO2) and fractional oxygen extraction using near-infrared spectroscopy (NIRS). We investigated whether there was a difference in peripheral muscle SvO2 (pSvO2) and peripheral fractional oxygen extraction (pFOE) in preterm neonates with early inflammation/infection compared to healthy subjects during the first 72 h after birth.Materials and MethodsWe retrospectively analyzed secondary outcome parameters of prospective observational studies, including preterm neonates at risk of infection in whom peripheral NIRS measurements were performed in combination with venous occlusions. Early neonatal inflammation/infection was diagnosed by clinical signs and laboratory parameters. Peripheral muscle tissue oxygenation index (pTOI) was measured using either NIRO 300 or NIRO 200-NX (both Hamamatsu Photonics, Japan) on the patients' lower legs. Using 20-s venous occlusions, pSvO2 and pFOE were calculated incorporating simultaneous measurements of arterial oxygen saturation (SpO2).ResultsWe analyzed measurements from 226 preterm neonates (median gestational age 33.9 weeks), 64 (28.3%) of whom were diagnosed with early neonatal inflammation/infection. During the first 24 h after birth, pSvO2 (66.9% [62.6–69.2] vs. 69.4% [64.6–72.0]; p = 0.04) and pTOI (68.6% [65.3–71.9] vs. 71.7% [67.3–75.1]; p = 0.02) were lower in those neonates with inflammation/infection, while there was no such difference for measurements between 24–48 and 48–72 h.DiscussionNIRS measurement of pSvO2 and pFOE is feasible and may be utilized for early detection of impaired peripheral oxygen delivery. As pTOI was also significantly lower, this parameter may serve as substitute for diminished regional oxygen supply.
Highlights
Adequate oxygen supply for preterm neonates may be defined through non-invasive measurement of venous oxygen saturation (SvO2) and fractional oxygen extraction using near-infrared spectroscopy (NIRS)
A blood culture was taken on the first day of life; according to previously published criteria [6], early inflammation/infection was defined by characteristic clinical signs and a positive blood culture and/or a C-reactive protein (CrP) level above the cut-off value of 10 mg/l
Our study showed that calculation of peripheral muscle SvO2 (pSvO2) and peripheral fractional oxygen extraction (pFOE) using non-invasive NIRS measurements is feasible in preterm neonates and may contribute relevant information to inform clinical practice
Summary
Adequate oxygen supply for preterm neonates may be defined through non-invasive measurement of venous oxygen saturation (SvO2) and fractional oxygen extraction using near-infrared spectroscopy (NIRS). We investigated whether there was a difference in peripheral muscle SvO2 (pSvO2) and peripheral fractional oxygen extraction (pFOE) in preterm neonates with early inflammation/infection compared to healthy subjects during the first 72 h after birth. To define “adequacy of oxygenation” in preterm neonates it has been recently suggested by Andersen et al [3, 4] to focus on the venous oxygen reservoir rather than on SpO2, as the latter may be relatively constant even in times of low oxygen supply or increased oxygen consumption [3]. While invasive measurement of SvO2 is impractical in preterm neonates, utilization of near-infrared spectroscopy (NIRS) offers the possibility to measure SvO2 from peripheral muscle tissue non-invasively. With impairment of oxygen delivery likely being a dynamic process, we took changes over time into account and, divided the observation period of 72 h after birth into three 24-h intervals
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
