Kidney Injuries on the Rise

Acute kidney injury requiring dialysis has become more common

(RxWiki News) Kidney injury does not always require dialysis. But when injuries are severe enough, patients need dialysis to do the job of their kidneys. Now it appears these severe kidney injuries may be on the rise.

Researchers found that severe acute kidney injuries - which require dialysis - may have become more common in recent years.

From 2000 to 2009, the rate of severe acute kidney injury increased 10 percent each year and increased more than two-fold overall. A statistical review also showed that deaths linked to acute kidney injury more than doubled during that same time period.

"Ask a doctor how you can protect your kidneys."

For their study, Raymond K. Hsu, MD, of the University of California San Francisco (UCSF), and colleagues looked at a national database to estimate the total number of severe acute kidney injuries - or kidney injury requiring dialysis - in the United States.

Dialysis is a process used to remove waste from the blood. It performs the work of the kidneys in people with severe kidney damage or kidney failure. Dialysis is associated with a variety of risks, including infection, hospitalization and death.

Dr. Hsu and colleagues found:

  • The rate of severe acute kidney injury increased from 222 cases per million person-years in 2000 to 533 cases per million person-years in 2009, which comes out to an average increase of about 10 percent per year.
  • There were about 18,000 deaths associated with severe acute kidney injury in 2000. In comparison, there were about 39,000 deaths associated with severe acute kidney injury in 2009.
  • Older people, men and blacks had higher rates of severe acute kidney injury.
  • The large increase in rates of severe acute kidney injury occurred in patients of all ages, sexes and races.

"That was a staggering revelation of how increasingly common and how life-threatening acute kidney injury has become over the past decade in the United States," said Dr. Hsu.

About 30 percent of these increased rates can be linked to common risks, such severe infections, use of ventilators, acute heart failure and cardiac catheterizations (inserting a tube into the heart to treat heart problems).

Still, researchers and doctors are unsure about what else may be causing the rise in acute kidney injury and how this growing problem can be addressed.

According to senior author Chi-yuan Hsu, MD, also from UCSF but not related to Dr. Raymond Hsu, acute kidney disease is largely a silent epidemic. That is mainly because a single kidney can continue to function without a patient knowing of any damage, even if much of that kidney is damaged or has stopped working.

"Even if you were to lose 80 percent of your kidney function, you wouldn't feel it," said Dr. Chi-yuan Hsu. However, when the kidney damage gets so severe that a patient needs dialysis, the outcome can be deadly, he explained.

In the study, about one-fifth of patients on dialysis died.

This study is just the beginning of figuring out why acute kidney injury has become more common and how to stop the problem in the future, the researchers said.

More research is needed to figure out what is driving growing rates of severe acute kidney injury, said Dr. Raymond Hsu.

"Is it because there are more interventions in modern medicine that are harmful to the kidneys? We did examine four factors in this paper but those only appeared to explain a fraction of the increase in incidence. Once we identify factors, hopefully we can intervene to reduce the number of acute kidney injury cases," he said.

"We hope that clinicians, researchers and the general public can gain a higher appreciation of the devastating impact of acute kidney injury that is comparable to the near universal, basic understanding of other forms of acute organ injury, such as heart attack and stroke," he added.

For their study, the researchers pulled data from the Nationwide Inpatient Sample - a database that tracks all causes of hospitalizations in the United States.

The research was supported by the National Institute of Diabetes and Digestive and Kidney Diseases. The authors reported no financial disclosures. The study was published December 6 in the Journal of the American Society of Nephrology.

Review Date: 
December 10, 2012