Abstract

Objective

During cardiopulmonary bypass (CPB) in open heart surgery, anticoagulation must be performed so that blood can circulate without clotting in extracorporeal circuits. In order to determine whether the necessary anticoagulation is provided, activated clotting time (ACT) is measured. In this retrospective study, the effect of ACT values measured during CPB on platelet (PLT) counts in the postoperative period was compared with PLT counts in the preoperative period.

Materials and Methods

40 patients who underwent open heart surgery with CPB in Tekirdağ Namık Kemal University Faculty of Medicine Hospital between 2019-2020 were examined in terms of age, gender, weight, CPB duration, ACT values, and preoperative and postoperative PLT values. The patients included in the study were divided into two groups of 20, based on the highest ACT values measured during the surgery: between 480-700 and over 700. Independent sample T and chi-square tests were applied for statistical analysis.

Results

In our study, we found that PLT levels decreased independently of ACT. In both Group I (p=0.000) and Group II (p=0.000), postoperative PLT levels showed a statistically significant decrease compared to preoperative PLT levels. Despite this significant decrease within the groups, no change was observed between the groups (p>0.05).

Conclusion

We believe that the decrease in PLT levels is not related to ACT levels; it occurs due to extracorporeal circuit elements, shear stress caused by the membrane oxigenator, priming, heparinization and hemodilution due to bleeding. The limited number of patients, the inability to measure aPTT as well as ACT in the intraoperative period and the factor 10 (FXa) level, another coagulation marker, in the postoperative period, and the inability to measure thromboestrogram, which is a PLT function test, are the limiting factors of our study.