Abstract :
Keywords NIRS; Regional oxygen saturation; Preterm infants; NEC Highlights * This is the first report of weekly measurements for both cerebral and splanchnic regional tissue oxygen saturation. * Previous studies have examined more mature preterm infants and focused on early oxygenation measurements only * Cerebral tissue oxygen saturation is higher than splanchnic throughout, and decreases over, the first 8 weeks. * Awareness of this increases the clinical potential of NIRS to alert to deviations from the norm * This potentially allows earlier identification of important neonatal conditions including NEC Abstract Background To investigate regional splanchnic and cerebral tissue oxygen saturation in preterm infants Methods Cerebral (cTOI) and splanchnic (sTOI) Tissue Oxygenation Index were measured weekly in 5 min epochs for a total period of 60 min using NIRS (NIRO-300) for the first 8 weeks of life, in 48 appropriately grown preterm infants born at Results Median birthweight 789 g (460--1486), gestational age 25.sup.+6 weeks (23.sup.+0--29.sup.+1) and 51.4% female. 217 NIRS measurements were completed across the first 8 weeks of life. Mean weekly cTOI ranged from 56.8--65.4% and sTOI ranged from 36.7--46.0%. Mean cTOI was significantly higher than mean sTOI (p Conclusions This is the first report of regional cerebral and splanchnic tissue oxygen saturation ranges during the first 8 weeks of life for preterm infants born at Author Affiliation: (a) Homerton University Hospital NHS Foundation Trust, London, UK (b) Queen Mary University of London, London, UK (c) Department of Medical Physics and Biomedical Engineering, University College London, London, UK (d) Imperial College Healthcare NHS Trust, London, UK (e) Imperial College London, UK (f) UCL Great Ormond Street Institute of Child Health, London, UK (g) St George's, University of London, London, UK * Corresponding author at: Neonatal Service, Homerton University Hospital NHS Foundation Trust, Homerton Row, London E9 6SR, UK. Article History: Received 14 October 2021; Revised 8 January 2022; Accepted 11 January 2022 Byline: Claire N. Howarth [Claire.howarth@nhs.net] (a,b,*), Terence S. Leung (c), Jayanta Banerjee (d,e), Simon Eaton (f), Joan K. Morris (g), Narendra Aladangady (a,b)