Protamine/heparin 0.6 ratio in cardiac surgery

Introduction In cardiac surgery, haemostasis is key.¹ Adequate heparinization is necessary to attain perioperative prevention of thrombus formation during cardio-pulmonary bypass (CPB).² To counteract the heparin effect, protamine hydrochloride is administered.³ The main objective of this retrospective study was to analyse the effect of a protamine/heparin 0.5-0.7/1 ratio, which was implemented in our hospital as of May 2017, versus a ratio > 0.7-1.0/1 on postoperative blood loss and transfusion rate after cardiac surgery. Methods This retrospective study was conducted at a non-academic teaching hospital and based on a prospectively collected database. All patients that underwent cardiac surgery requiring CPB between May 2016 and May 2018 were included. The main outcome variables 12h postoperative total chest tube production and the total amount of blood and blood component transfusions were compared between groups by the use of the Chi-square and Mann-Whitney U test. Results A total of 1939 patients were included. We compared 1150 patients with a 0.5-0.7/1-protamine/heparin ratio versus 789 patients with > 0.7/1-protamine/heparin ratio (Table 1). Pre-operative coagulation values were within the normal range. The median 12h postoperative blood loss was 230 mL in the 0.5-0.7-ratio group versus 260 mL in the >0.7 ratio group (p The amount of patients that received blood component transfusion (composite endpoint of fresh frozen plasma (FFP), packed red blood cells (PRBC), fibrinogen concentrate (FC), platelet concentrate (PC) and prothrombin complex (PCC)) was significantly different. In the 0.5-0.7-protamine/heparin-ratio group 71.3% of the patients were transfusion free, compared to 62,5% of transfusion free patients in the high ratio group (p Discussion A average 0.6-protamine/heparin-ratio after CPB in cardiac surgery is associated with a reduced 12h postoperative blood loss and a reduced amount of patients that received blood or blood components transfusion, compared to > 0.7-protamine/heparin ratio.