The candidate, Melania M. Bembea, is on faculty at the Johns Hopkins University, in the Department of Anesthesiology and Critical Care Medicine. Her goal is to become an independent clinician scientist focused on applying rigorous research design to quality improvement in the pediatric intensive care unit, with an emphasis on evaluating complications and outcomes associated with the use of extracorporeal life support technologies in critically-ill newborns. To realize this goal, she is on course to complete the PhD track of the Johns Hopkins Graduate Training Program in Clinical Investigation, and she will receive structured mentoring by senior investigators for the conduct of supervised, innovative research.
The specific aims and related hypotheses of the proposed research are: [Aim 1. Determine if periods of lost cerebrovascular auto regulation during ECMO in neonates are correlated with periods of elevations in plasma biomarkers for brain injury (e.g. GFAP). Hypothesis: Periods of loss of cerebrovascular auto regulation occur frequently during ECMO in infants, and these periods expose the brain to ischemia which leads to the release of protein biomarkers into the systemic circulation.
Aim 2. Determine if periods of loss of auto regulation and release of protein biomarkers for brain injury into the systemic circulatio during ECMO are correlated with conventional neuroimaging markers for injury including cranial ultrasound and magnetic resonance imaging (MRI). Hypothesis: The length and severity of periods of loss of cerebrovascular auto regulation and the release of protein biomarkers from brain injury into the systemic circulation will correlate with elevations in neuroimaging markers for injury and will occur before changes in neuroimaging.
Aim 3. Determine if elevated plasma brain injury biomarker concentrations and loss of auto regulation during ECMO as well as neuroimaging markers of brain injury are independent predictors of survival and neurologic outcomes at hospital discharge, and at 6 months and 1 year post-ECMO. Hypothesis: Elevations in brain injury biomarkers and periods of loss of cerebrovascular auto regulation as well as neuroimaging markers for brain injury (head ultrasound and MRI) will predict later neurological disability, but changes in biomarkers and auto regulation will provide an earlier correlate of injury.] Completion of the proposed research will significantly advance our knowledge of how best to monitor for and diagnose impending or incident brain injury during ECMO and plan for neuroprotective interventions in future trials [(e.g., targeting blood pressure to a level above an individual's lower cerebral blod flow auto regulatory threshold during ECMO vs. standard blood pressure management)]. These projects and the career development plan described will build a foundation for a successful career as an independent investigator.
Extracorporeal membrane oxygenation (ECMO) is a life-saving technique by which critically-ill patients with refractory heart and lung failure are being salvaged in the intensive care unit. However, ECMO is fraught with complications, the most feared one being brain injury such as brain hemorrhage or ischemia. This proposal seeks to use non-invasive methods of real-time monitoring for brain injury risk factors (e.g., altered cerebrovascular auto regulation) and for incident brain injury during ECMO (e.g., by measuring plasma brain injury biomarkers serially), in an effort to develop new preventive strategies or, when injury already happened, to implement neuroprotective interventions earlier than what is possible with today's clinical care capabilities.