Everyone experiences a decline in kidney function with age, some more than others. In certain casesusually as a result of diabetes or high blood pressureloss of function can be extreme and lead to chronic kidney disease. Chronic kidney disease develops over months or yearssometimes silentlyand affects more than 20 million Americans.
But now, experts are warning peopleespecially older adultsabout the rising number of cases of another kind of kidney diseaseacute kidney injury (AKI). AKI develops quickly, causing a sudden and severe drop in kidney function. The number of Americans who each year experience severe AKI that requires dialysis has more than doubled in the past decade. AKIs killed nearly 39,000 Americans in 2009, up from 18,000 in 2000.
AKI most often targets people over 60 and strikes for a variety of reasons. It's most commonly set off by
- serious infections,
- major surgery (especially open-heart procedures),
- heart failure and
- exposure to certain drugs.
Patients who have chronic renal failure (CRF) also are at increased risk for suffering acute kidney injury.
AKI is a widespread problem in hospitals. Studies show that 5 percent of all hospital patients develop AKIa figure that may climb as high as 23 percent in intensive care units. The most common cause of AKI among hospitalized patients is sepsis, a severe reaction to bacterial infectionanother scourge in hospitals. Likewise, up to 30 percent of patients who undergo cardiac surgery develop AKI.
Any direct harm to a kidneysuch as trauma from an accident or a serious burncan bring on this dangerous condition as well. Blood clots, dehydration and urinary-tract blockages can place the kidneys in immediate peril, too.
In September 2014, the U.S. Food and Drug Administration (FDA) approved the first test to help detect AKI risk in critically ill patients. Other diagnostic tests are only able to determine whether patients already have the condition. The new test, called NephroCheck, allows for closer monitoring of patients at high risk for developing AKI in the 12 hours following administration of the testhelping to prevent permanent kidney damage.
Loss of Kidney Function
The kidneys are a pair of bean-shaped, fist-sized organs located in the lower back, on either side of the spine. Think of the kidneys as your body's filtration system: As blood passes through them, the kidneys sift out waste products and excess fluid, which are removed from the body and come out in the urine. The kidneys also produce various hormones that help regulate blood pressure, make red blood cells and maintain healthy bones.
AKI causes an abrupt and dramatic drop in the kidneys' filtering capacity, causing waste products and fluid to accumulate in the blood, which can occur over a period of daysor hours. A patient who lacks working kidneys must undergo dialysis, a procedure that filters the blood (either by being connected to an artificial kidney or through a special process in which blood is cleaned inside the body).
A Doctor's Viewpoint
Karl L. Womer, MD, Associate Professor of Medicine Clinical Director, Transplant Nephrology Johns Hopkins Medicine
About 30 percent of all AKI cases requiring dialysis are a result of increasing use of cardiac catheterization and ventilators, and the rise of hospital-acquired infections and acute heart failure. More research is needed to determine what’s responsible for the remaining 70 percent. Also, many people don't initially realize they have kidney diseasethe kidneys are remarkably resilient, and it's possible for them to function normally at about half capacity with few or no symptoms.
By the time damage is discovered, it can be severe enough to require dialysis permanently or, if caught early enough, only temporarily until the kidneys heal and return to normal function. Regular follow-up with your doctor, who can monitor your kidney function, is very important.
Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50; Updated by Remedy Health Media