Análisis de la endotoxemia en el postoperatorio de cirugía cardiaca

Abstract

Since the beginning of cardiac surgery, development of new surgical techniques, advances in methods of cardiopulmonary bypass (CPB) and intensive care treatments, mortality has decreased from almost 100% to 5- 6% today. However, these figures have remained stable in recent years. The inflammatory response to CPB has been implicated in many of the postoperative clinical problems that often occur in these patients including respiratory failure, postoperative shock states, renal failure and multiple organ dysfunction syndrome. These systemic changes may be due to many different mechanisms. One mechanism, is attributed to splanchnic hypoperfusion that might cause harm to the intestinal mucosa by altering the barrier’s permeability, thus favouring bacterial translocation and endotoxemia. Endotoxin is a lipopolysaccharide in the membrane of GNB and is known to be one of the most potent activators known of innate immunity and the inflammatory response in humans. In patients subjected to cardiac surgery, transient endotoxemia has been shown in many occasions, which seems to be closely related to extracorporeal circulation, but the magnitude of endotoxemia and their correlation with clinical evolution and the development of complications vary widely between studies. According to some studies, systemic endotoxin concentration is closely correlated with the degree of cardiovascular dysfunction, duration of CPB, ischemic time and need for vasoactive amines, which can be summarized in all situations that could potentially favor a situation of splanchnic hypoperfusion. There are different techniques to detect the presence of endotoxemia. The amount of endotoxin has traditionally been quantified by the analysis known as “Limulus amebocyte lysate” (LAL), but this test has never been approved by the FDA for clinical use in humans. This has led to the discovery of a new test called endotoxin activity assay (EAA) (Spectral Diagnostics, Toronto, ON, Canada), comprising a rapid chemiluminiscent immunodiagnostic test kit that can be performed in less than 1 hour, approved by the FDA for its realization in biological fluids such as it is blood. The purpose of the study was to assess the prevalence of endotoxemia related to CPB in a cohort of patients undergoing cardiac surgery, using the EAA test. There was also investigated the criteria for high risk of endotoxemia and the association between endotoxemia and the development of adverse clinical events including length of stay and mortality. The study was performed in the Intensive Care Unit of Germans Trias i Pujol Hospital, in Badalona. A total of 107 patients were enrolled. Of these 107 patients, the median age was 66 years (36-87), most were males (69%), 38% had DM, 71% HTA and 12% peripheral vascular disease. Median EuroSCORE I was 7 (0-6). Only 23 patients had EAA ≥0,4 EA. Median CBP time was 95 (24-300) and isquemic time 68 (17-175) minutes. 37% required blood transfusion. The results of the study indicate that in postoperative cardiac surgery there is endotoxemia at least in moderate degree, and that the presence of endotoxemia is significantly related to early postoperative infection. As a risk factor, we found that patients with peripheral vascular disease and transfused more than 2 during surgery are those with increased risk of endotoxemia. [-]

Date of Award	30 Jan 2015
Original language	English
Supervisor	Teresa M. Tomasa (Director) & Jaume Fernandez-llamazares Rodriguez (Director)