NCT02595385 (CONSERVE).

Study name	CONSERVE
Methods	Adult participants aged between 18 and 80 years undergoing single procedure cardiac surgery will be randomised to one of four groups. The method of randomisation and allocation concealment is not described. The study is described as triple‐blinded (participants, investigators, and outcome assessors all blinded to intervention allocation).
Participants	Adult participants between 18 and 80 years of age undergoing single procedure cardiac surgery will be randomly allocated to one of four groups (below). The target recruitment number is N = 240. Retrograde autologous prime alone (RAP) Cell salvage alone (CS) RAP and CS No intervention (Control) Inclusion criteria Under 80 years of age Undergoing single procedure surgery Be on single antiplatelet therapy To have stopped warfarin preoperatively with an international normalised ratio (INR) of < 1.5 Have stable coronary disease Have good left ventricular function Exclusion criteria "Redo procedures" (revisions) Emergency surgery Be on dual antiplatelet therapy Have preoperative kidney dysfunction with an estimated glomerular filtration rate (eGFR) < 60 mL/min Have postoperative drainage > 200 mL per hour or require re‐exploration for bleeding
Interventions	RAP alone: retrograde autologous prime of the bypass circuit. To remove 500 to 900 mL of fluid. Cell salvage alone: reinfusion of shed blood during the operation RAP and cell salvage: RAP and CS used in combination Control group: no intervention
Outcomes	Number of units of packed red blood cells transfused, adverse reaction to RAP measured by systolic blood pressure (BP) < 90 mmHg during initiation of bypass
Starting date	February 2015 Estimated study completion date: August 2016 (not updated since November 2015)
Contact information	Contact: Alison Murphy 028 9063 6349 alison.murphy@belfasttrust.hscni.net Contact: Christine Fawsett 028 92 603107 info.orecni@hscni.net
Notes	Transfusion protocol: a transfusion protocol is not described Prospective registration status: study was prospectively registered on ClinicalTrials.gov (date of registration 03 November 2015) Ethical approval: unclear whether the study has been approved by an ethics committee or institutional review board Language: information available on ClinicalTrials.gov is in English