Description:
<jats:title>Abstract</jats:title><jats:p><jats:styled-content style="fixed-case">M</jats:styled-content>ultisite near infrared spectroscopy (<jats:styled-content style="fixed-case">NIRS</jats:styled-content>) monitoring during pediatric cardiopulmonary bypass (<jats:styled-content style="fixed-case">CPB</jats:styled-content>) has not been extensively validated. Although it might be rational to explore regional tissue saturation at different body sites (namely brain, kidney, upper body, lower body), conflicting results are currently provided by experience in children. The aim of our study was to evaluate absolute values of multisite <jats:styled-content style="fixed-case">NIRS</jats:styled-content> saturation during <jats:styled-content style="fixed-case">CPB</jats:styled-content> in a cohort of infants undergoing pediatric cardiac surgery to describe average differences between cerebral, renal, upper body (arm), and lower body (thigh) regional saturation. Furthermore, the correlation between cerebral <jats:styled-content style="fixed-case">NIRS</jats:styled-content> and cardiac index (<jats:styled-content style="fixed-case">CI</jats:styled-content>) at <jats:styled-content style="fixed-case">CPB</jats:styled-content> weaning was evaluated. Twenty‐five infants were enrolled: their median weight, age, and body surface area were 3.9 (3.3–6) kg, 111 (47–203) days, and 0.24 (0.22–0.33) m<jats:sup>2</jats:sup>, respectively. <jats:styled-content style="fixed-case">M</jats:styled-content>edian <jats:styled-content style="fixed-case">A</jats:styled-content>ristotle score was 8 (6–10), and vasoactive inotropic score at <jats:styled-content style="fixed-case">CPB</jats:styled-content> weaning was 16 (14–25). A total of 17 430 data points were recorded by each sensor: two‐way <jats:styled-content style="fixed-case">ANOVA</jats:styled-content> showed that time (<jats:styled-content style="fixed-case"><jats:italic>P</jats:italic></jats:styled-content> < 0.0001) and site (<jats:italic>P</jats:italic> = 0.0001) significantly affected variations of <jats:styled-content style="fixed-case">NIRS</jats:styled-content> values: however, if cerebral <jats:styled-content style="fixed-case">NIRS</jats:styled-content> values are excluded, sensor site is no more significant (<jats:italic>P</jats:italic> = 0.184 in the no circulatory arrest [noCA] group and <jats:italic>P</jats:italic> = 0.42 in the circulatory arrest [CA] group). Analysis of <jats:styled-content style="fixed-case">NIRS</jats:styled-content> saturation changes over time showed that, at all sites, average <jats:styled-content style="fixed-case">NIRS</jats:styled-content> values increased after <jats:styled-content style="fixed-case">CPB</jats:styled-content> start, even if the increase of cerebral saturation was less intense than other sites (<jats:italic>P</jats:italic> < 0.0001). Detailed analysis of interaction between site of <jats:styled-content style="fixed-case">NIRS</jats:styled-content> measurement and time point showed that cerebral <jats:styled-content style="fixed-case">NIRS</jats:styled-content> (ranging from 65 to 75%) was always significantly lower than that of other channels (<jats:italic>P</jats:italic> < 0.0001) that tended to be in the range of oversaturation (80–90%), especially during the <jats:styled-content style="fixed-case">CPB</jats:styled-content> phase. Average cerebral <jats:styled-content style="fixed-case">NIRS</jats:styled-content> values of patients who did not undergo circulatory arrest (<jats:styled-content style="fixed-case">CA</jats:styled-content>) during <jats:styled-content style="fixed-case">CPB</jats:styled-content>, 10 min after <jats:styled-content style="fixed-case">CPB</jats:styled-content> weaning, were associated with average <jats:styled-content style="fixed-case">CI</jats:styled-content> values with a significant correlation (<jats:italic>r</jats:italic> = 0.7, <jats:italic>P</jats:italic> = 0.003). In conclusion, during <jats:styled-content style="fixed-case">CPB</jats:styled-content>, cerebral <jats:styled-content style="fixed-case">NIRS</jats:styled-content> values are expected to remain constantly lower than somatic sensors, which instead tend to show similar elevated saturations, regardless of their position. Based on these results, positioning of noncerebral <jats:styled-content style="fixed-case">NIRS</jats:styled-content> sensors during <jats:styled-content style="fixed-case">CPB</jats:styled-content> without <jats:styled-content style="fixed-case">CA</jats:styled-content> may be questioned.</jats:p>