[Dynamic changes in regional cerebral oxygen saturation variability within the first week after birth and relationship with brain injury type in preterm infants].

OBJECTIVES

To investigate the dynamic changes in regional cerebral oxygen saturation (rScO2) variability within the first week after birth in preterm infants and its relationship with different types of brain injury.

METHODS

A retrospective study included 70 preterm infants with a gestational age of 28-32 weeks admitted to Cangzhou People's Hospital from August 2021 to June 2025. All infants underwent continuous near-infrared spectroscopy (NIRS) monitoring of rScO₂ within the first 7 days after birth. Based on cranial ultrasonography and magnetic resonance imaging findings, infants were divided into intraventricular hemorrhage (IVH) group (n=23), periventricular leukomalacia (PVL) group (n=18), hypoxic-ischemic encephalopathy (HIE) group (n=11), and control group (n=18). The coefficient of variation (CV), slope, peak, and trough values of rScO2 were calculated across different time windows, and their correlations with brain injury type and severity were analyzed.

RESULTS

Within the first 7 days after birth, rScO2 CV showed a biphasic pattern characterized by an initial increase, followed by a decrease, then a second increase and decrease. The first high-variability period occurred at 0 to <24 hours, and the second at 72 to <120 hours. The CV at 6 hours after birth was positively correlated with brain injury severity (rs=0.72, P<0.001). The area under the receiver operating characteristic curve (AUC) for diagnosing brain injury using 6-hour CV was 0.862 (P<0.05). A combined predictive model incorporating CV values at 6, 24, and 72 hours achieved an AUC of 0.924 (P<0.05).

CONCLUSIONS

The variability of rScO2 within the first week after birth in preterm infants exhibits a biphasic fluctuation pattern. Different brain injury types show characteristic variability patterns, and early CV values can serve as sensitive indicators for early identification of brain injury.