PRE-PERFUSION LACTATE LEVEL AND LACTATE-PYRUVATE RATIO AS A PROGNOSTIC CRITERION OF DEVELOPMENT OF POST-PERFUSION CARDIAC FAILURE DURING THE MYOCARDIAL REVASCULIZATION SURGERY WITH THE USE OF CARDIOPULMONARY BYPASS

Abstract

Goal of the study: to detect the correlation between lactate and pyruvate levels and their ratio (LPR) during ischemia/reperfusion with the post-operative increase of troponin I as a marker of myocardial lesion. Materials and methods. The study was performed among the patients undergoing myocardial revasculization surgery with the use of cardiopulmonary bypass in order to evaluate the prognostic opportunities to predict development of post-perfusional cardiac failure. 56 patients with coronary disease who underwent surgery with cardiopulmonary bypass were examined. The samples of blood for lactate and pyruvate tests were collected from the catheter of heart coronary sinus before aortic compression, before release of the clamps and in 30 minutes after reperfusion. During the surgery the following rates of hemodynamic profile were registered (cardiac index, systolic output index, medium arterial tension, index of peripheral resistance and pulmonary vessels resistance, index of systolic output of the left and right ventricles, pulmonary capillary wedge pressure), oxygen transportation, consumption and extraction co-efficient, arteriovenous oxygen difference. In the early post-operative period the following rates were evaluated: need in inotropic support, duration of artificial pulmonary ventilation and stay in the intensive care department. The level of troponin I was tested in 12 and 24 hours. Correlations were evaluated for the whole group in general, and in certain subgroups the patients were divided into basing on LPR value before aortic compression. Group 1 (LLPR) included 24 patients with LPR lower than the medium level of the cohort (M 17.6), Group 2 (HLPR) included 29 patients with LPR above the medium level. No significant differences were found between the groups. Results. The obtained results confirmed the certain dependence between the lactate level and increase of plasmic troponin I. However it was shown that the strong correlation between them could manifest only if the initial levels per-perfusional lactate level and lactate-pyruvate ratio had been high. The pre-perfusional lactate level did not allow predicting the development of post-perfusional cardiac failure. High values of lactate-pyruvate ratio prior to the start of cardiopulmonary bypass reflected the probability of this complication. This fact allows treating patients with high LPR as a group undergoing the advanced risk of the unfavorable course of the post-operative period. The increase of lactate in blood collected from coronary sinus of such patients during anoxia is to be regarded as an argument for adequate increase of myocardium protection. Conclusion: In order to evaluate the risk of post-reperfusional cardiac failure the routine testing of the lactate level in coronary sinus is to be supplemented by testing of the pyruvate level.

Keywords

• cardiopulmonary bypass
• coronary disease
• lactate
• pyruvate
• lactate-pyruvate ratio