With high rates of acute kidney injury (AKI) affecting so many, it's time to expand the discussion about kidney-related diseases. AKI, the abrupt or rapid loss of kidney function, may not have the same notoriety as chronic kidney disease or end-stage renal disease, but the significant increase in cases of AKI can no longer be ignored.
In the study "Temporal Changes in Incidence of Dialysis-Requiring AKI
," researchers found that from 2000 to 2009, incidences of dialysis-requiring AKI, the most serious form of the disease, averaged a 10 percent increase per year. Also during this period, deaths related to dialysis-requiring AKI doubled. While not well-known, AKI is quickly becoming a major public health concern. This is especially true of older people, black people, and males, whom the disease disproportionately affects. In addition to changing demographics, increased incidences of sepsis and acute heart failure, or increased use of cardiac catheterization and mechanical ventilation, can also account for about one-third of the rise in cases of dialysis-requiring AKI.
The Expert Take
Non-dialysis requiring AKI cases outnumber dialysis-requiring AKI cases ten-fold, but a lack of dialysis does not make for a better outlook on the situation. Rather, "It means that the burden of AKI is higher than we report here," Drs. Chi-Yuan Hsu and Raymond Hsu said. "AKI that is severe enough to warrant dialysis occurs in roughly about one in every 10 cases of AKI. Therefore, our study results reporting only dialysis-requiring AKI represent the 'tip of the iceberg' in the overall public health problem of AKI. Prior studies have shown that even mild cases of AKI (not requiring dialysis) are associated with increased morbidity, mortality, and healthcare costs."
Particularly alarming is the difficulty in detecting the disease. "Unfortunately, acute kidney injury in and of itself is largely silent, especially in mild cases, and therefore can be missed," the researchers said. "In severe cases, patients may experience decreased urine output, leg swelling, shortness of breath, decreased appetite, and fatigue. Most of the symptoms patients will experience are associated with conditions that cause AKI, such as a major infection."
No consensus has been reached as to why black people and males have higher incidences of AKI, but some answers have been found for why it affects older people at such alarming rates. "Older people have higher prevalence of conditions such as hypertension, diabetes, and baseline chronic kidney disease that put them at risk for dialysis-requiring AKI," the researchers said. "Older patients are also more likely to be exposed to medications and procedures that may be directly toxic to the kidneys."
Source and Method
Researchers analyzed data from the Nationwide Inpatient Sample, a nationally representative administrative database of hospitalizations. Further research is needed to more accurately explain the disparities behind the groups most affected, and in the future, could be supplemented to include clinical as well as administrative data.
More questions remain as to why AKI affects certain people more than others. But because it has been shown that older people, black people, and males suffered from the most cases of dialysis-requiring AKI, they are among the demographics that should take the most care. The same goes for people who have undergone certain medical procedures including cardiac catheterization and mechanical ventilation.
"Because AKI occurs in a variety of hospital settings, there is no uniform way to prevent AKI," the researchers said. "We know from some prior studies and our experience that careful dosing of medications, lessening exposure to intravenous contrast material, paying close attention to patient's hydration status, and prevention of hospital-acquired infections are some useful strategies. There is also some data to support earlier involvement of nephrologists in the care of patients with AKI may improve clinical outcomes.
Hospital settings aside, there is slightly more power at the individual level. "Since individuals with baseline chronic kidney disease are the ones most likely to suffer acute kidney injury, those individuals should discuss carefully with their doctors the risk and benefits of procedures and interventions which may trigger acute kidney injury," the researchers said. "They should communicate to all their providers such as surgeons or emergency room doctors that they do have underlying chronic kidney disease, so that appropriate decisions are made regarding procedures and medications in those settings."