Patients in an ICU often require large amounts of IV fluid to maintain adequate cardiac function. In patients with renal failure, the ability to gauge adequacy of circulating blood volume based on urine output is obviously lacking. The FDA approved devices called Flotrac/Vigileo and Crit-Line are used in this setting to determine adequacy of fluid resuscitation. This study proposes to use the data collected in a retrospective manner to determine if correlation of the various measured parameters can serve as a predictor of hemodynamic status.