Comparing acute normovolumic hemodilution with autologous platelet-rich plasma for blood preservation during aortic surgery : study protocol for a randomized controlled clinical trial

Background Both acute normovolumic hemodilution (ANH) and autologous platelet-rich plasma (aPRP) have been demonstrated blood-protective effects in cardiac aortic surgery; however, the efficacies of the two methods have not been compared. This study aims to compare the effects of aPRP and ANH prior to aortic surgery on postoperative bleed and other outcomes. Methods and analysis This is a prospective, single-center, double-blind controlled clinical trial including 160 patients randomized 1:1 to receive aPRP (test group) or autologous whole blood (ANH, control group). The primary objective is to compare the drainage volumes in the two groups at 24, 48, and 72 h postoperatively. Secondary outcomes include input of allogeneic blood and blood products and durations of aortic block, extracorporeal circulation, deep hypothermic arrest of circulation, tracheal extubation, hospital stay, requirement for secondary surgical hemostasis, and application of intra-aortic balloon pump or extracorporeal membrane oxygenation in the two groups. In addition, heart rate, systolic blood pressure, diastolic blood pressure, central venous pressure, and thromboelastography recorded before blood reservation (T1), after blood reservation (T2), before blood transfusion (T3), and after the blood is returned (T4) to the transfusion will be compared between the two groups of patients. Discussion This study will demonstrate if the use of aPRP could reduce the risk of bleeding after aortic surgery compared with ANH. The results are expected to have practical clinical applications in terms of more effective blood protection and shorter hospital stay. Trial registration This study was registered with the Chinese Clinical Trial Registry ( http://www.chictr.org.cn/ ) with the ID ChiCTR 1900023351.Registered on May 23, 2019. Trial status Recruiting start date: July 1, 2019; expected recruiting end date: July 1, 2024 Version number and date: Version 2 of 05-04-2019