Clinical Usefulness of Regional Tissue Oxygen Saturation Monitoring Using Near-Infrared Spectroscopy in Neonates

Abstract

Objective: Recently, near-infrared spectroscopy (NIRS) has been introduced in the neonatal intensive care unit (NICU) to monitor the altered hemodynamic status causing cerebral hypoxemia or affecting mesenteric and/or renal oxygenation. This study aimed to reassess the clinical usefulness of NIRS and the correlation between regional O2 saturation (rSO2) and various physiological parameters in neonates. Methods: Thirty-nine newborns, admitted in NICU from June 2019 to June 2020 and continuously monitored with NIRS (cerebral and renal) during the first 72 hours, were included. Results: Among 39 newborns with a median gestational age of 33.9 weeks, and a median birth weight of 2,180 g, the median of the cerebral and renal rSO2 were 84% (30%–95%) and 95% (45%–95%), respectively. Cerebral rSO2 tended to increase over time since the time of delivery, while renal rSO2 tended to decline, especially in preterm infants. Average of renal rSO2 during 72 hours showed a statistically significant difference between term and preterm infants (P<0.05). Cerebral rSO2 showed significant correlation with hemoglobin (r=0.35, P<0.05) and hematocrit (r=0.37, P<0.05). Renal rSO2 showed significant correlation with capillary blood gas analysis such as pH (r=0.36, P<0.05), pCO2 (r=-0.19, P<0.05), pO2 (r=0.23, P<0.05), base excess (r=0.19, P<0.05), hemoglobin (r=0.33, P<0.05), hematocrit (r=0.32, P<0.05) as well as renal function indicator such as blood urea nitrogen (r=-0.50, P<0.05) and creatinine (r=-0.59, P<0.05). Conclusion: We re-evaluated the clinical usefulness of NIRS in neonates by identifying trends and correlations of rSO2 with clinical parameters. It is necessary to confirm its effectiveness through further study.