Patients are often older, present with oliguric acute kidney injury (AKI), and may have underlying chronic kidney disease (CKD), and have been exposed to high osmolar agents, such as intravenous immunoglobulin (IVIG), high-osmolar radiocontrast agents, or other osmotic agents. Some patients have a history of sepsis and received hydroxyethyl starch as a volume expander. Patients may show low-level proteinuria due to tubular injury and characteristic vacuolated tubular cells on urinalysis. When injury from IVIG is recognized early and therapy is discontinued, nearly all patients recover kidney function, although one-third may need temporary dialysis.