The incidence of acute kidney injury (AKI) requiring dialysis is now higher than the incidence of end-stage renal disease (ESRD) requiring dialysis or transplant, discovered a team led by Chi-yuan Hsu, MD, Nephrology Division Chief at the University of California-San Francisco (UCSF), and UCSF nephrology fellow Raymond Hsu, MD.
The two doctors (who are not related) collaborated on their written responses to questions posed by Renal & Urology News regarding the findings, which were published online ahead of print on December 6, 2012, in Journal of the American Society of Nephrology (“Temporal Changes in Incidence of Dialysis-Requiring AKI”).
Were you surprised to find that from 2000 to 2009, the incidence of dialysis-requiring AKI increased by an average of 10% per year and the total number of associated deaths during that period more than doubled, from 18,000 to nearly 39,000?
We expected to see an increase in the incidence of dialysis-requiring AKI as well as the number of deaths, because of prior literature showing increases in incidence of some conditions and procedures that are risk factors for AKI, such as sepsis. However, we were surprised by the rate of rise, which was very rapid.
To what do you attribute this increase?
In our study, we found that about 30% of the total increase in dialysis-requiring AKI may be attributed to trends in certain conditions and procedures over the same period, such as sepsis, acute heart failure, cardiac catheterization, and mechanical ventilation. However, we are not completely certain as to what other factors are responsible for the rest of the increase.
In a statement issued by the American Society of Nephrology, Dr. Chi-yuan Hsu noted that the incidence of dialysis-requiring AKI is now higher than the incidence of end-stage renal disease that requires dialysis or a transplant. For comparison, what are those incident rates?
The incidence of end-stage renal failure (ESRD) that requires dialysis or a transplant has been fairly stable since the mid 2000s. For comparison, in 2005, the incidence of ESRD was 354 cases per million persons, while the incidence of dialysis-requiring AKI was 386 per million persons. In 2009, the incidence of ESRD was 375 per million persons, while the incidence of dialysis-requiring AKI was 533 per million persons.
It should be noted that in AKI, if dialysis is required, it is temporary; whereas in ESRD, dialysis is permanent. Now, there are cases of non-recovery of kidney function whereby patients pass from dialysis-requiring AKI to become ESRD (many consider three months a reasonable cutoff point—that is, after three months on dialysis for AKI, the person is considered to have ESRD and to require permanent dialysis).
Finally, there is such a higher mortality rate associated with dialysis-requiring AKI—about one-fifth of the patients in our study who had dialysis-requiring AKI died during hospitalization—that many individuals die before they are eligible to be placed on permanent dialysis.