Background: Our aim was to evaluate the degree of agreement between the Vigileo/Flotrac system and ODM in measurement of stroke volume and CO and to investigate the correlation between FTC and SVV for production of fluid response. Methods: Prospective single centre study on 25 patients admitted to critical care department to undergo major abdominal surgeries. Vigileo/flutrac system was studied and compared to ODM as a reference technique. Results: An average of 156 paired data of SV and CO were used. The vigileo flotrac monitor produced reliable SVV or prediction of fluid need. Sensitivity 35.7% and specificity 91.3%. However CO x SV measured by Vigileo flotrac compared to ODM shower percentage error 35% and 40% respectively and a bias of 1.1+1.96 L/min and limits of agreement of 2.7-5 L/min for CO measurements. Conclusion: The precision of SV and CO estimation by Vigileo/flotrac remains insufficient to allow the replacement of the ODM as a reference technique.