Sepsis is the most common cause of childhood death worldwide. Millions of children survive, but are left with impaired health. Sepsis-related Acute Kidney Injury (sAKI) is increasingly recognized as a significant factor associated with long-term mortality among different patient populations. Renal dysfunction and subsequent chronic kidney disease is implicated in the development of hypertension and cardiovascular disease. The investigators overall hypothesis is that, in the pediatric population, sepsis-related AKI will have unrecognized, long-term consequences with regard to kidney function, endothelial function, blood pressure control, and overall health.