The most common causes of kidney injury are blunt trauma (usually from motor vehicle accidents) and penetrating wounds (usually from gunshots and knifing wounds). However, it is well known that certain sports can lead to kidney injury as well:
- Football, hockey, rugby, lacrosse
- Soccer, biking, horseback riding, ice skating
Symptoms of Kidney Injury
The best indicator for kidney injury is blood in the urine (hematuria). It can range from microhematuria (not visible to the naked eye) to profuse bleeding. However, the absence of blood in the urine doesn’t rule out kidney injury. For example, it can be seen in severe injury where the blood vessel or ureter is ripped away from the kidney.Flank or abdominal tenderness or pain is often seen in kidney injury from direct trauma, especially when kidneys are crushed against the ribs. You can often find broken ribs and bruising at the same time.
If there is significant blood loss, the blood pressure may be low and the heart pounding at a fast rate. If severe, life-threatening shock and death can follow.
- Blood in the urine
- Flank / abdominal pain and broken ribs
- Hypotension and shock
Evaluation and Diagnosis
Assuming it’s not a life-threatening situation, the best way to check for kidney injury is to look for blood in the urine with a urine dipstick and to get an abdominal CT scan. A CT can help diagnose bleeding from the kidney, deep cuts or lacerations, and damage to the blood vessels and ureter. It is absolutely critical that intravenous dye be given to help assess the level of damage.Plain x-rays, kidney ultrasound, and intravenous pyelograms (IVP) or urograms (IVU) have been used in the past but they have been essentially replaced by the CT. If there is concern that a blood vessel, ureter, or the bladder has been damaged, more invasive diagnostic studies may be necessary. This is usually only necessary in severe trauma, as seen in motor accidents.
- Urine dipstick for blood in urine
- Abdominal CT scan with intravenous contrast
Treatment and Management
Most injuries to the kidney are minor and can be treated with pain medications, bed rest and observation. With severe kidney injury, surgery may be necessary to stop the bleeding and repair or save the kidney. Sometimes the kidney is so badly damaged that part or all of it has to be removed. When this happens, it is important to know that the other kidney is working well.
Prognosis
Most cases of kidney injury do not result in permanent damage to or loss of the kidney. Complications can occur so close monitoring and follow-up are important. Some complications to watch out for include:- Delayed bleeding
- Infection or abscess
- Urine leaking or obstruction
Sources
- J Kevin Smioth, MD, PhD. Kidney, Trauma. eMedicine [online]. Accessed August 16, 2006.
- Douglas Geehan, MD. Renal Trauma. eMedicine [online]. Accessed August 16, 2006.