Kidney Injuries

The kidney is injured more often than any of the organs along the urinary tract. Blunt force due to motor vehicle accidents, falls, or sports injuries is the usual cause of injury. Penetrating kidney injuries can result from gunshot or stab wounds. Less commonly, injuries can occur during diagnostic tests, such as a kidney biopsy. Injuries may also occur occasionally during various treatments, such as those for kidney stones, including extracorporeal shock wave lithotripsy or percutaneous procedures.

Symptoms and Diagnosis

If kidney injuries are not treated or are very serious, complications, such as kidney failure, high blood pressure, delayed bleeding, and infection may result.

See the figure Kidney Injuries: Minor to Severe.

The history of events, the person's complaints, and a physical examination help a doctor diagnose a kidney injury. Blood in the urine (visible or microscopic) is the strongest indicator of a kidney injury. With major kidney injuries, low blood pressure and anemia may occur if the person loses a significant amount of blood. Other indicators of a kidney injury include bruising of the flank (the area between the ribs and hip), marks made from a seat belt, fractures of the lower ribs, or pain in the upper abdomen. Most blunt kidney injuries are minor and may result in nothing more than a microscopic amount of blood in the urine. With penetrating injuries, the location of the wound (whether in the upper or mid abdomen, back, or flank) may help a doctor determine if the kidney is involved.

A suspicion of an injury can be evaluated by imaging the kidneys and urinary tract. This is best accomplished using computed tomography (CT) or intravenous urography to accurately determine the location and extent of the injury. Occasionally, additional imaging tests may be needed to confirm the diagnosis.

Treatment

In general, most people recover from their kidney injuries, provided they are diagnosed and treated promptly. Treatment begins with steps to control blood loss and to prevent shock. Fluids are given intravenously to help keep blood pressure within a normal range and stimulate urine production. For minor kidney injuries, careful control of fluid intake and bed rest are often the only treatment needed, because these measures allow the kidney to heal itself. Major injuries usually require surgical repair. Blood transfusions may be needed; rarely, the injured kidney needs to be removed.

Kidney failure may require lifelong treatment. Other complications of kidney injuries that require treatment include high blood pressure, delayed bleeding, and infection.