Relationship between Brain Metabolism and Injury in Post-Cardiac Arrest Comatose Patients

Abstract

Cardiac arrest is a leading cause of death in the United States contributing to 5.6% of annual deaths. More than 80% of survivors are in permanent coma and 50-80% of those will die. Despite advancements in cardiac care, the mechanisms underlying brain injury are complex and not well understood, which has limited advancement in brain targeted therapies. Specifically, the relationship between regional brain metabolism and risk of brain injury is not known. This thesis investigated the relationship between brain injury in post-cardiac arrest comatose patients and metabolic characteristics: cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rate of oxygen (CMRO2), and cerebral metabolic rate of glucose (CMRglu) in healthy normal brains. The study analyzed whole brains, brains clustered by injury percentages, and brain regions clustered by injury percentage. Resulting correlations showed that CMRO2 and CMRglu had stronger correlations with brain injury than CBF and CBV, indicating a closer link between oxygen and glucose utilization and brain damage. Patients with minimal injury exhibited weak correlations, while patients with moderate to severe injuries displayed stronger correlations, emphasizing the critical role of oxygen and glucose metabolism in brain damage progression.