Safety and Efficacy of the Gastric Reactance (XL) in Patients Post-operated of Elective Cardiac Surgery

Evaluate the safety and effectiveness of the XL trend measured by Florence (Critical Perfusion Inc, Palo Alto, California) in the prediction of morbimortality of Mexican patients post-operated of elective cardiovascular surgery. Hypothesis: 1. The gastric reactance measurement (XL) correlates with the morbimortality (postoperatory shock, excessive bleeding, vasoplegic syndrome and death) and with the risk predictors (APACHE II, STS, SOFA, and EUROSCORE II) with patients post-operated of elective cardiac surgery. 2. It is possible to identify the cut-off point of the values of the gastric reactance (XL) as a predictive tool of morbimortality in patients post-operated of elective cardiac surgery. 3. The gastric reactance (XL) is a safe measurement to patients undergoing cardiac surgery.