Modeling Cerebral Blood Flow Dependence on Carbon Dioxide and Mean Arterial Blood Pressure in the Immature Brain With Accounting for the Germinal Matrix.

Intraventricular hemorrhage () is one of the most critical complications in the development of preterm infants. The likelihood of is strongly associated with disturbances in cerebral blood flow () and with microvascular fragility in the germinal matrix (). The value and its reactivity to changes in arterial carbon dioxide pressure ( ) and mean arterial blood pressure () are relevant indicators in the clinical assessment of preterm infants. The objective of the present study is mathematical modeling of the influence of and on in immature brain, based on clinical data collected from 265 preterm infants with 23-30 gestational weeks. The model was adapted to the peculiarities of immature brain by taking into account the morphological characteristics of the capillary network and vascular reactivity, according to gestational and postnatal age. An analysis of model based values of and its reactivity to changes in and was performed separately for each gestational week and for the first two days of life both for preterm infants with and without . The developed model for the estimation of was validated against equivalent experimental measurements taken from the literature. A good agreement between the estimated values of , as well as its reaction on changes in and and the equivalent values obtained in experimental studies was shown.