Post-Neutralisation Activated Clotting Time and Postoperative Transfusions in Cardiac Surgery Outcome

OBJECTIVE: To assess the impact of post-protamine neutralisation activated clotting time (ACT) values on postoperative outcomes including chest drain output, transfusion requirements, and CICU stay, in patients undergoing cardiac surgery. STUDY DESIGN: Observational comparative study. Place and Duration of the Study: Department of Anaesthesiology, The Aga Khan University Hospital, Karachi, Pakistan, from February to August 2023. METHODOLOGY: Ethical approval was obtained to collect data from elective cardiac surgery patients' charts. A sequential sampling approach analysed the baseline and post-protamine neutralisation ACT values, categorising patients into two groups. Group A maintained ACT within 10% of baseline, while Group B deviated. The outcomes measured included transfusion needs, chest drain output, additional protamine, cardiac intensive care unit (CICU) stay, and postoperative reopening. Statistical analysis included mean, median, frequency, t-test / Mann-Whitney U test, and Chi-square test. RESULTS: The study comprised 101 patients (39 in Group A, 62 in Group B), with similar baseline health. No significant differences were found in tranexamic acid use, CICU stay, chest drain output, or transfusion rates between the groups (p >0.05). CONCLUSION: Maintaining ACT within 10% of baseline post-protamine neutralisation results in similar intraoperative and postoperative outcomes, suggesting potential benefits in avoiding the aggressive protamine therapy and ensuring haemostasis in cardiac surgery. KEY WORDS: Coronary Artery bypass grafting, Cardiopulmonary bypass, Activated clotting time (ACT), Heparin, Postoperative bleeding, Blood transfusions.