Introduction: The aim of this study was to investigate whether the doses of heparin and protamine used for anticoagulation and neutralization during cardiopulmonary bypass (CPB) vary according to ABO blood groups and demographic characteristics. Methods: A total of 839 patients who underwent cardiac surgery between 2015 and 2025 were included in the study. The distribution of ABO blood groups was as follows: 325 patients with blood group A, 292 with group O, 160 with group B, and 62 with group AB. Among these patients, 762 were Rh-positive and 77 were Rh-negative. Patient records were reviewed to collect data on intraoperative heparin and protamine doses, activated clotting time (ACT) values, demographic characteristics, and blood group types. Patients were classified according to preoperative ABO blood group, and comparisons were made based on these classifications. Results: No statistically significant differences were observed in heparin–protamine neutralization doses according to ABO blood group, Rh factor, sex, or diabetes mellitus (p > 0.05). However, patients without hypertension and those using preoperative acetylsalicylic acid (ASA) required significantly higher protamine doses for neutralization (p < 0.05). Conclusion: In this study, no relationship was found between ABO blood group and heparin–protamine doses used during CPB. However, preoperative ASA use and hypertension were associated with variations in protamine dosing. Considering that variations in thrombotic events after cardiac surgery can result in significant morbidity and mortality, further well-designed and comprehensive studies are warranted.
Kirişçi et al. (Tue,) studied this question.