The influence of carbon dioxide field flooding in mitral valve operations with cardiopulmonary bypass on S100? level in blood plasma in the aging brain

摘要

Introduction: The risk of air microembolism during cardiopulmonary bypass (CPB) is high and influences the postoperative outcome, especially in elderly patients. The use of carbon dioxide (CO2) atmosphere during cardiac surgery may reduce the risk of cerebral air microembolism. The aim of our study was to assess the influence of CO2 field flooding on microembolism-induced brain damage assessed by the level of S100? protein, regarded as a marker of brain damage. Materials and methods: A group of 100 patients undergoing planned mitral valve operation through median sternotomy using standard CPB was recruited for the study. Echocardiography was performed prior to and after the CPB. CO2 insufflation at 6?L/minute was conducted in the study group. Blood samples for S100? protein analysis were collected after induction of anesthesia, 2?hours after aorta de-clamping, and 24?hours after operation. Results: The S100? level in blood plasma did not differ significantly between the study and the control group (0.13±0.08?μg/L, 1.12±0.59?μg/L, and 0.26±0.23?μg/L and 0.18±0.19?μg/L, 1.31±0.62?μg/L, and 0.23±0.12?μg/L, P =0.7, 0.14, and 0.78). The mean increase of the S100? concentration was 13% lower in the group with CO260?years, there were significant differences in the S100? level 2 and 24?hours after the procedure (1.59±0.682?μg/L vs 1.223±0.571?μg/L, P =0.048, and 0.363±0.318?μg/L vs 0.229±0.105?μg/L, P =0.036) as compared with younger patients. Conclusion: The increase in S100? concentration was lower in the group with CO2 protection than in the control group. Age and an addition of TVA significantly influenced the level of S100? concentration in the tests performed 2?hours after aortic clamp release.