Influencia de la hemólisis en la hemostasia de pacientes sometidos a cirugía de recambio valvular aórtico

Abstract

Despite the enormous advances, both technical and in knowledge, regarding the use of surgery with extracorporeal circulation, it continues to cause very important alterations related to the activation of the hemostatic and inmune systems. These alterations can be subclinical, or evolve into dysfunctions affecting several systems, including hemorrhagic diathesis and hemolysis with multi-organ failure. In addition, hemolysis can lead to significant alterations in platelet function since hemoglobin has the capacity to chelate antiplatelet compounds such as nitric oxide. Goals: 1. Main: • To study the influence of hemolysis on hemostasis in patients undergoing valve replacement surgery. 2. Secundary: • To assess the effects of valve replacement surgery on the basic parameters of the blood count and general biochemistry. • To investigate the effects of valve replacement surgery on biochemical parameters that indicate hemolysis. • To elucidate the effects of hemolysis on platelet function in patients undergoing valve replacement surgery. Material and methods: The samples were collected from 33 patients at three different times: M1 (baseline), M2 (during cardiopulmonary bypass) and M3 (after ten minutes of cardiopulmonary bypass) to analyze, through the parameters of Complete blood count and by flow cytometry, the study of platelet function: aggregation, activation and phosphorylation of the VASP protein, in the presence of the nitric oxide (NO) donor NONOate. Results and conclusions: 1. During aortic valve replacement surgery with CPB, no alterations in hemostasis have been recorded, since the parameters analyzed have remained within normal ranges, although they have had statistically significant variations between the groups. 2. During aortic valve replacement surgery, the hemolysis that occurs is not significant enough to cause alterations in hemostasis, understood as alterations in platelets and coagulation, which have remained within the ranges of normality. 3. Aortic valve surgery with extracorporeal circulation produces a decrease in baseline hemoglobin that is statistically significant although it remains within normal levels. 4. In the biochemical parameters of hemolysis, we found statistically significant differences in haptoglobin and LDH levels with respect to the baseline, data that indicates a certain degree of hemolysis produced by CPB and after completion of CPB. Despite this, both haptoglobin and LDH values remain within normal limits. These results support the conclusion that hemolysis in the study population undergoing aortic valve replacement is not clinically significant. 5. In the presence of NONOate, a clear inhibition of platelet reactivity is observed, as well as an increase in VASP phosphorylation in the three experimental groups, which leads us to conclude that the bioavailability of NO is high enough to exert its inhibitory effect on platelets. This finding supports the conclusión that hemolysis in the study population undergoing aortic valve replacement is not clinically significant. 6. Based on the analysis of all the results of our study, we can conclude that, during aortic valve replacement surgery with CPB, the hemolysis that occurs is not significant enough to generate alterations in hemostasis in the patients studied