The rational is that ICAM-1 is expressed by ischemic endothelium and facilitates neutrophile migration into areas of necrotic epithelium. We will determine whether rising urinary ICAM-1 will identify patients with progressive dialysis-dependent ATN. Specific aim #3 will also examine whether a reduction in dialysis or all cause mortality by fenoldopam mesylate correlates with reduced urinary expression of ICAM-1 or other cell adhesion molecules. The serum, plasma, urine supernatant and urinary casts obtained from patients enrolled in this trial will be made available to other investigators involved in the study of early ATN.