To evaluate the effects of limiting hydration during prostate mobilization on intraoperative blood loss.

The patient records of 519 consecutive men undergoing radical retropubic prostatectomy by a single surgeon from January 2000 through April 2003 were reviewed. In the initial 328 cases, intravenous fluids were not limited throughout the case (constant hydration group). In the next 189 cases, intravenous fluids were limited to a target of 1500 mL during prostate dissection (delayed hydration group). After the prostate was removed, hydration was brisk for an additional target of 3500 mL. The patient characteristics, perioperative events, and postoperative recovery were evaluated.

Delayed hydration resulted in a statistically significant reduction in estimated blood loss compared with the constant hydration group, averaging 700 mL versus 965 mL, respectively. The immediate postoperative hematocrit values were also significantly greater in the delayed hydration group (31.5%) than in the constant hydration group (30.2%). Furthermore, the delayed hydration group had significantly fewer cases of blood loss greater than 1500 mL and fewer patients needed intraoperative transfusions. No statistically significant difference was found in total intravenous fluids given and no increased morbidity occurred with delayed hydration.

Delayed hydration appears to reduce blood loss during radical retropubic prostatectomy. In the hemodynamically stable patient, limiting intravenous fluids before complete dissection of the prostate is feasible without increasing morbidity.