Brain Oxygenation changes during Heart Surgery

This pilot study is using a non-invasive light-based brain monitoring technique called broadband near-infrared spectroscopy to measure brain oxygen and metabolism in real-time during heart surgery. When surgeons use a heart-lung bypass machine during cardiac surgery, blood pressure can drop significantly, and this may reduce oxygen delivery to the brain — a potential cause of cognitive problems after surgery. Both adults and children who are undergoing heart surgery using cardiopulmonary bypass will be monitored with optical probes placed on the forehead. This technique allows researchers to track not only how much oxygen is in the brain's blood vessels, but also how well the brain's energy-producing processes are working. The study will explore whether drops in blood pressure during surgery affect these brain energy markers. You may be eligible if you are undergoing heart surgery that requires a heart-lung bypass machine. Children and adults can both participate. People with certain skull or brain abnormalities affecting the front of the head are not eligible as the monitoring probes cannot be placed appropriately. This is a feasibility pilot study that will inform the design of larger studies aiming to prevent brain injury during cardiac surgery.