Autotransfusion system or integrated automatic suction device in minimized extracorporeal circulation: influence on coagulation and inflammatory response

Abstract

To measure surrogate markers of coagulation activation as well as of the systemic inflammatory response in patients undergoing primary elective coronary artery bypass grafting (CABG) using either the so-called Smart suction device or a continuous autotransfusion system (C.A.T.S.®). Fifty-eight patients being operated with a miniaturized circuit (minimal extracorporeal circuit, MECC) were prospectively randomized to using a so-called Smart suction device or a routine continuous autotransfusion system (C.A.T.S.®) for collection of mediastinal shed blood. The coagulation response was measured by thrombin-antithrombin complex (TAT) and D-dimer. The inflammatory response was measured by Interleukin 6 (IL-6) and complement factor 3a (C3a) at three different time points, before surgery, 2h after surgery, as well as 18 h after surgery. No serious adverse cardiovascular event was observed. Serum levels of TAT significantly differed between both groups 2h after surgery (Smart suction 16.12 ± 13.51 μg l⁻¹ vs C.A.T.S® 9.83 ± 7.81 μg l⁻¹, p = 0.040) and returned to baseline values after 18 h in both groups. Serum levels of D-dimer showed a corresponding pattern with a peak 2h after surgery (Smart suction 1115 ± 1231 ng ml⁻¹ vs C.A.T.S.® 507 ± 604 ng ml⁻¹, p = 0.025). IL-6 levels also significantly differed between both groups 2h after surgery (Smart suction 186 ± 306 pg ml⁻¹ vs C.A.T.S.® 82 ± 71 pg ml⁻¹, p = 0.072). No significant changes in serum levels of C3a over time could be observed. Despite no differences in the clinical course of patients with either Smart suction or C.A.T.S.® being observed, surrogate markers of coagulation and inflammation seem to be less pronounced in patients where cardiotomy blood is not being directly reinfused. As such, C.A.T.S.® should be preferred in routine CABG, as long as no extensive volume substitution is anticipated.