Does supply meet demand? A comparison of perfusion strategies on cerebral metabolism in a neonatal swine model

ABSTRACT Objective We aimed to determine the effects of selective antegrade cerebral perfusion (SACP) compared to other perfusion strategies on indices of cerebral blood flow (CBF), oxygenation, cellular stress, and mitochondrial function. Methods One-week-old piglets (n=41) were assigned to five treatment groups. Thirty-eight were placed on cardiopulmonary bypass (CPB). Of these, 30 were cooled to 18oC and underwent deep hypothermic circulatory arrest (DHCA) (n=10), SACP at 10cc/kg/min (n=10), or remained on continuous CPB (DHCPB, n=10) for 40 minutes. Other subjects remained on normothermic CPB (n=8), or underwent sham surgery (n=3). Novel, noninvasive optical measurements recorded CBF, cerebral tissue oxyhemoglobin concentration [HbO2], oxygen extraction fraction (OEF), total hemoglobin concentration (THC), and cerebral metabolic rate of oxygen (CMRO2). Invasive measurements of cerebral microdialysis and CBF were recorded. Cerebral mitochondrial respiration and reactive oxygen species (ROS) generation were assessed following sacrifice. Results During hypothermia, DHCA piglets experienced increases in OEF (p Conclusions SACP meets cerebral metabolic demand and mitigates cerebral mitochondrial ROS generation. Excess oxygen delivery during deep hypothermia may have deleterious effects on cerebral mitochondria that may contribute to adverse neurological outcomes. We describe noninvasive measurements that may help guide perfusion strategies.