2020 Volume 47 Issue 2 Pages 115-121
Recently, it is recommended to keep activated clotting time (ACT) more than 480 seconds during cardiopulmonary bypass (CPB) according to the guideline of American Society of ExtraCorporeal Technology (AmSECT). However, it is not rare than ACT does not exceed 480 seconds after administration of unfractionated heparin (UFH). We retrospectively investigated parameters which influenced heparin reactivity in 137 patients out of 272 patients who underwent cardiovascular surgery with CPB from May 2017 to December 2018. One hundred thirty-five patients were excluded to remove influences of initial UFH dose. Heparin reactivity decrease was recognized in 41 (30%) patients. Between patients with decreased heparin reactivity (Low group) and others(Hi group), there were significant differences in age, aortic regurgitation (AR), Hb, TP, ALB/TP, preoperative ACT (PreACT), total UFH dose, and antithrombin (AT) dose. In multivariate analysis, Alb and PreACT were identified as independent parameters influencing decreased heparin reactivity. The evaluation of the suitability of parameters obtained from ROC curve suggested decreased heparin reactivity might be observed when the albumin concentration is 3.8g/dL (cutoff value) or less.