Impact of Hyperoncotic Albumin to Support Blood Loss Replacement

Fluid treatment is usually performed with either balanced crystalloid fluids or iso-oncotic colloids, (synthetic colloids, plasma and 5% albumin). Doubts have been raised about synthetic colloids (impairment of renal function and coagulation), and the natural albumin has been used more extensively. Albumin is the main protein responsible for plasma oncotic pressure and its volume expansion effect. An alternative therapeutic option is the mobilization of tissue fluid by infusing a small amount of hyper-oncotic fluid like the 20% albumin solution (endogenous fluid recruitment). The primary objective of this study is to test the effect of 20% albumin on plasma volume expansion and fluid recruitment in the frame of blood loss replacement during cystectomy using established fluid kinetic models. The investigators expect that fluid replacement with crystalloid will be better sustained intravascularly with the administration of 20% albumin and be able to recruit fluid into the vascular compartment.