Extra-Cellular Hemoglobin and Organ Injury in Extended Cardiopulmonary Bypass During Complex Cardiac Surgery

What this Trial Is About

Researchers are investigating how red blood cells break down during cardiopulmonary bypass (CPB) used in complex cardiac surgeries, such as heart valve replacement or coronary artery bypass grafting (CABG). The study focuses on understanding how hemoglobin released into plasma (plasma free hemoglobin, pfH) from damaged red blood cells contributes to organ injury, including the brain, lungs, heart, and kidneys. The research aims to set safe limits for pfH levels during CPB and to develop computer models that predict organ injury risk by measuring pfH and protective proteins that clear it from the blood. Participants in this observational study are patients undergoing complex cardiac surgeries requiring CPB for more than one hour. Researchers will collect blood and urine samples during and after surgery to monitor changes in pfH and protective proteins like haptoglobin, hemopexin, and transferrin. These biological samples will help compare new methods for detecting red blood cell damage with existing laboratory tests. The study does not involve any experimental treatments but focuses on detailed biological specimen collection. During the study, participants will have blood and urine collected at multiple time points during surgery and up to five days after the procedure. Researchers will measure hemolysis (red blood cell breakdown) and kidney injury markers to assess organ damage related to CPB. The study will evaluate changes from baseline at hourly intervals during surgery and daily post-surgery to understand injury dynamics. Participants will be monitored under usual care, and the study aims to improve early detection and prevention strategies for organ injury in cardiac surgery patients.

Cardiopulmonary Bypass Induced Red Blood Cell Lysis