Early cerebral hemodynamic assessment using resistive index and its correlation with neonatal outcomes.

BackgroundCerebral blood flow (CBF) is critical for neonatal brain health, and disruption of autoregulation may predispose infants to brain injury. The resistive index (RI) of the anterior cerebral artery (ACA), measured via Doppler ultrasonography, is a widely used non-invasive marker of CBF, but its relationship with vital parameters in critically ill neonates remains uncertain.MethodsThis retrospective study at Taipei Veterans General Hospital from January 2022 to December 2024 included neonates admitted to the NICU with ACA Doppler ultrasonography within 24 h of birth. RI values were stratified into three groups: low (<0.6), normal (0.6-0.8), and high (>0.8). Clinical characteristics, resuscitation needs, Apgar scores, blood gas analyses, and short- and long-term outcomes were compared across groups.ResultsAmong 898 admissions, 386 neonates met the inclusion criteria (mean gestational age 35 ± 4 weeks, mean birth weight 2382 ± 847 g), abnormal RI was identified in 25.1% (low RI: 4.1%, high RI: 21.0%). Abnormal RI correlated with significantly lower pH, higher pCO2, lower 5-min Apgar scores, and greater need for delivery room intubation (p < 0.01). After adjusting for gestational age, birth weight, and evaluation timing, low RI remained independently associated with increased risks of systemic hypotension and fluid resuscitation (p < 0.05).ConclusionAbnormal ACA RI within 24 h of birth is associated with cerebral hemodynamic instability in critically ill neonates. Early RI assessment may provide insights into neonatal hemodynamic status and serve as a supplemental clinical indicator for identifying high-risk infants in the NICU.