Background: Cerebral hypoxia-ischemia impairs brain development in extremely preterm infants and is associated with poor neurological outcomes. Near-infrared spectroscopy (NIRS) is a noninvasive continuous monitoring method for regional cerebral oxygen saturation (rcSO2).Purpose: This study evaluated the clinical feasibility and neurological impact of a neurocritical care bundle that incorporates prolonged multidisciplinary hemodynamic monitoring and a stepwise management algorithm.Methods: Preterm infants with a gestational age (GA) ≤28 weeks or birth weight (BW) ≤1,000 g were prospectively enrolled in a bundle group subjected to NIRS for rcSO2, electrical cardiometry for cardiac output, and daily brain and cardiac echography during the first 72 hours of life. Monitoring was repeated weekly in the first month and then monthly until discharge or the term-equivalent age (TEA) was reached. We implemented a stepwise management algorithm for treating cerebral hypoxia. The primary outcome was a composite of mortality and adverse neurological events (structural abnormalities or electroencephalogram-confirmed seizures) before discharge. The secondary outcomes were the physiological pattern of rcSO2 within the initial 72 hours and up to discharge or TEA.Results: Thirty preterm infants (GA, 27.1±2.0 weeks; BW, 830±225 g) were enrolled in the bundle group. The mean time-averaged rcSO2 (66.8%±10.3%) was not associated with GA or BW. However, postnatal age appeared to influence physiological rcSO2 changes, given that rcSO2 values were higher during the initial 72 hours than at subsequent intervals. Seven infants (23.3%) had poor outcomes and significantly lower time-averaged rcSO2 (51.1% [50.0%–65.2%] vs. 71.8% [67.1%–73.1%], P=0.002). Multivariate regression indicated that a lower rcSO2 was an independent risk factor, and a 65% threshold showed an optimal predictive value for poor outcomes.Conclusion: The neurocritical care bundle helped identify preterm infants at risk of cerebral hypoxia, and lower rcSO2 was an independent risk factor for composite mortality and adverse neurological outcomes.

Background: Cerebral blood flow (CBF) is essential for maintaining cerebral metabolism in extremely preterm infants; however, no universally accepted reference standard exists for CBF velocity (CBFV). This study aimed to establish physiological reference patterns of middle cerebral artery CBFV under strictly defined physiological stability using multimodal monitoring. Methods: This post-hoc analysis included extremely preterm infants (gestational age ≤ 28⁺⁶ weeks or birthweight 500–1000 g) from a prospective cohort study. Serial Doppler ultrasonography of the middle cerebral artery was performed along with near-infrared spectroscopy and electrical cardiometry. Normal CBFV datasets were defined based on systemic stability, adequate cardiac output (>150 mL/kg/min), normal regional cerebral oxygen saturation (65–85%), and the absence of major comorbidities. Associations between Doppler parameters and postmenstrual age (PMA) and concurrent weight were analyzed using generalized estimating equations. Results: Forty infants contributed 194 normal CBFV datasets. Physiological reference ranges for peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV), resistance index (RI), and pulsatility index (PI) were established across PMA and concurrent weight strata. Both PSV and MV were associated with PMA and concurrent weight (p < 0.01), whereas EDV, RI, and PI were not. Mean blood pressure was not significantly associated with CBFV parameters. Conclusions: PSV and MV were maturation-dependent cerebral perfusion markers. Multimodally defined physiological stability provides a robust framework for establishing clinically relevant reference values for middle cerebral artery CBFV in extremely preterm infants.