Cross-sectional association between red blood cell distribution width and regional cerebral tissue oxygen saturation over the first 14 days in preterm infants

Abstract Background: Hypoxia can threaten the metabolic functions of various body systems of the immature neonate, particularly the central nervous system. Red blood cell distribution width (RDW) has been recently reported as a prognostic factor in neurologic diseases. This study examined the correlation between RDW and regional cerebral tissue oxygen saturation (rcSO 2 ). Methods: This cross-sectional study, including 110 preterm infants with gestational age (GA) of <32 weeks or birth weight (BW) of <1500 g from January to June 2022 in our institution, monitored rcSO 2 with near-infrared spectroscopy. RDW was extracted from the complete blood count during the first 14 days of life. RDW and rcSO 2 measurements were analyzed using a cross-sectional research method. Results: This study included 53 preterm neonates with rcSO 2 ≥55% and 57 preterm neonates with rcSO 2 <55%. Mean rcSO 2 decreased with increasing RDW during the first 14 days of life. Significantly higher RDW levels were seen in the low rcSO 2 group compared with those of the high rcSO 2 group. According to threshold effect analysis, the value of rcSO 2 decreased with RDW levels above 17.84% (β, -0.03; 95% CI, -0.04– -0.02; p <0.0001). After adjusting for potential confounders, an RDW of ≥17.84% was determined as the predictive cutoff value for preterm infants with low rcSO 2 (Model I: OR, 3.31; 95% CI, 1.36–8.06; p =0.009; and Model II: OR, 3.31; 95% CI, 1.28–8.53; p =0.013). Conclusions: An RDW of ≥17.84% was associated with a high risk of low rcSO 2 in preterm infants. A high RDW in preterm infants correlates with an increased risk of cerebral hypoxia. Trial registration: This study was registered at ChineseClinicalTrials.gov (09/04/2022,ChiCTR2200058482).