 Interventions: Participants will be randomly assigned to 1 of 2 arms. Patients, families, clinicians, and research personnel will be blinded to the fluid administered 5 albumin or 0.9 normal saline. Fluid resuscitation will begin immediately after randomization and continue for the first 7 days or until discharge from the ICU or ED if this occurs sooner. Blood and urine will be collected at randomization and then at 6, 12, 24, 72 hrs and 7 days later. Study fluid will be administered as rapidly as possible as 500 ml fluid challenges. All other co-interventions of care will not be protocolized or mandated during the study period. 