In cases of blunt trauma, children with grade I renal injuries (contusions) can be discharged home without further imaging and followed with serial urinalyses Patients are instructed to limit daily activity until the urinalysis is within normal limits Outpatient radiographic evaluation is necessary if microscopic hematuria persists for more than 30 days Grade II and III renal injuries warrant admission to the hospital for a minimum of 24 hours when the risk of bleeding is highest Expectant treatment includes supportive care with bed rest, hydration, antibiotics, and serial hematocrits, although the evidence supporting these therapies is relatively low Once the gross hematuria resolves, these children may be discharged home with limited activity until microscopic hematuria resolves and repeat imaging demonstrates total healing Management of the remaining patients (with grade IV and V injuries) evokes significant controversy The shift from early operative intervention to a more expectant approach for most solid organ injuries has been increasingly applied to high-grade renal injuries Advocates of early surgical exploration argue that this approach results in decreases in morbidity, hospital stay, and complications without a significant increase in the risk for nephrectomy Opponents believe that nonoperative management of selected patients does not lead to negative consequences, may result in a higher renal salvage rate, and cuts down the morbidity associated with surgical exploration Nonoperative management requires admission to the hospital, serial examinations, and hematocrits Debate continues regarding the necessity of repeat CT scan at 36 to 72 for conservatively managed renal injuries According to expert opinion, repeat imaging is not required for grade I and II injuries and grade III injuries without hemodynamic instability or devitalized fragments Some authors are now beginning to advocate against routine repeat imaging for grade IV or V renal injuries when there is no clinical indication (e.g., sepsis, decrease in hematocrit, unstable blood pressure, increasing hematuria or oliguria), arguing that repeat scans rarely change the management of this population and that kidneys with stable or improved appearance on repeat CT still have a delayed complication rate of 25% Patients who demonstrate hemodynamic instability require surgical intervention or angiographic embolization of renal vessels Angioembolization should be performed only in those children who have a definable segmental artery injury Persistent urinary extravasation can be managed with percutaneous drainage or internal ureteral stenting These procedures, as well as embolization, should be limited to institutions that can provide appropriate resources