Arterial Carbon Dioxide Tension, Blood Pressure, and Cerebral Blood Flow in Very and Extremely Preterm Infants: A Narrative Review
Very preterm and extremely preterm infants have immature physiological function, and cerebral blood-flow regulation is particularly fragile. Fluctuations in arterial carbon dioxide tension (PaCO2) or blood pressure can therefore produce abnormal cerebral perfusion and increase the risk of brain injury. Both act on cerebral blood flow through cerebrovascular tone and hemodynamic status, and thereby on cerebral oxygenation and metabolism. Clinical and laboratory work has clarified part of this picture, but bedside cerebral blood-flow monitoring and individualized management strategies remain difficult. Here, we review the physiological basis of cerebral blood-flow regulation in this population, examine how fluctuations in PaCO2 and blood pressure disturb cerebral perfusion, appraise current monitoring and neuroprotective methods, and outline an integrated approach to optimizing cerebral blood-flow control. Our aim is to help clinicians reduce brain injury and improve neurodevelopmental outcome in this population.
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