Although fluid therapy is of paramount value in anesthetic practice, there is no guideline available for perioperative fluid management in major abdominal surgery. So, there is a need to establish whether goal directed fluid therapy protocol is effective during radical cystectomy and urinary diversion. A balance of perioperative fluid therapy is crucial, yet the method to achieve this equilibrium remains a highly debated subject. Therefore, this study will be designed to investigate the effects of two individualized goal directed fluid therapy during radical cystectomy to encourage an effective circulating blood volume and pressure. Accordingly, as a primary outcome, the investigators assume that stroke volume optimization could maintain better perioperative hemodynamic stability with low incidence and severity of hypotensive episodes together with achievement of maximal oxygenation. Hopefully this regimen could help to decrease the possibility of perioperative tissue hypoperfusion and the possible associated complications as a secondary outcome.