Kidney (Renal) Trauma

Blunt Trauma

The best sign of blunt kidney injury is blood in the urine (“hematuria”). Sometimes the blood can be seen with the naked eye. Other times, it can only be seen through a microscope.

Blunt trauma kidney injuries may show no outside signs. Sometimes bruises may be seen over the back or abdomen where the kidneys are located.  Flank pain is a common symptom of kidney trauma whether or not there is any outside bruising.

Penetrating Trauma

Penetrating kidney trauma may be suspected when a wound from a knife, bullet or other object has pierced the skin. Blood in the urine may also be seen with this type of trauma.

Kidney trauma can occur as a kidney injury alone or with other damaged organs. The kidney is the urinary tract organ most often injured by severe trauma.

Blunt trauma can be caused by

• Car accident
• Fall
• Being hit hard by a heavy object, especially in the flanks (between the rib and the hip)
• An action where the body comes to a sudden stop after moving quickly

Penetrating trauma can be caused by

• Bullet
• Knife
• Any object piercing the body

Kidney injury is rated on a five-grade scale. Grade one refers to minor injury, such as bruising. Grade five is the most severe, where the kidney is shattered or cut off from its blood supply.

A simple dipstick urine test can detect microscopic hematuria (blood in the urine).

When kidney injury is suspected, it’s important to get imaging studies of both kidneys. These will confirm the diagnosis and tell how bad the injury is.

Computerized Tomography

A computerized tomography (CT) scan with intravenous (IV) contrast (a special dye) is the best way to assess kidney injury. A CT scan takes many x-ray images that are put together to show “slices” of parts of the body. Injuries can be seen more clearly as the contrast dye flows through the blood and kidney.

Ultrasound

Ultrasound can also be used to diagnose kidney trauma. Ultrasound uses sound waves bouncing off structures in your body to create images. But it may not show the best details of the injury.

Intravenous Pyelogram

Intravenous pyelogram (IVP) uses x-rays to show how dye moves through your urinary system. IVP can show how the kidneys are working. The dye is injected into a vein in your arm.

Treatment depends on the condition of the patient, how bad the kidney injury is and if there are other injuries.

If the patient is stable and there’s no injury to other organs, the trauma might be treated without surgery. The patient will rest in the hospital until they are stable. They are watched closely for bleeding and other problems. After leaving the hospital, a patient should be watched for signs of kidney damage like late bleeding or high blood pressure.

If a patient isn’t stable and is losing a lot of blood or is leaking urine from the kidney, surgery may be done to fix and preserve the injured kidney. If the patient needs open surgery to repair other organs, the surgeon will check and fix the injured kidney as well. Sometimes a kidney is too badly injured and may need to be removed. Fortunately, kidneys are efficient organs and usually only one healthy kidney is needed for good health.

Today, most kidney injuries are handled without surgery. Many serious injuries can be treated with minimally invasive techniques. One method is angiographic embolization. Using this method, surgeons can reach the arteries of the kidneys through large blood vessels in the groin to stop bleeding.

The most common problems after treatment are leaking urine or delayed bleeding. These may be treated by using telescopes to reach the urinary tract (“endoscopy”) or angiographic embolization. If these things fail, surgery may be needed. The kidney may need to be taken out.

Another problem is a pus pocket (“abscess”) forming around a kidney. This is treated by draining the infection with a tube placed into the abscess. Sometimes surgery is needed to drain the abscess.

Some patients get high blood pressure after major kidney trauma. This may be treated with medication, or rarely with additional procedures.

Updated August 2024.