Long-Term Kidney Outcomes Following Dialysis-Treated Childhood Acute Kidney Injury: A Population-Based Cohort Study

Abstract

Background: AKI is common during pediatric hospitalizations and associated with adverse short-term outcomes. However, long-term outcomes among survivors of pediatric AKI who received dialysis remain uncertain.

Methods: To determine the long-term risk of kidney failure (defined as receipt of chronic dialysis or kidney transplant) or death over a 22-year period for pediatric survivors of dialysis-treated AKI, we used province-wide health administrative databases to perform a retrospective cohort study of all neonates and children (aged 0-18 years) hospitalized in Ontario, Canada, from April 1, 1996, to March 31, 2017, who survived a dialysis-treated AKI episode. Each AKI survivor was matched to four hospitalized pediatric comparators without dialysis-treated AKI, on the basis of age, sex, and admission year. We reported the incidence of each outcome and performed Cox proportional hazards regression analyses, adjusting for relevant covariates.

Results: We identified 1688 pediatric dialysis-treated AKI survivors (median age 5 years) and 6752 matched comparators. Among AKI survivors, 53.7% underwent mechanical ventilation and 33.6% had cardiac surgery. During a median 9.6-year follow-up, AKI survivors were at significantly increased risk of a composite outcome of kidney failure or death versus comparators. Death occurred in 113 (6.7%) AKI survivors, 44 (2.6%) developed kidney failure, 174 (12.1%) developed hypertension, 213 (13.1%) developed CKD, and 237 (14.0%) had subsequent AKI. AKI survivors had significantly higher risks of developing CKD and hypertension versus comparators. Risks were greatest in the first year after discharge and gradually decreased over time.

Conclusions: Survivors of pediatric dialysis-treated AKI are at higher long-term risks of kidney failure, death, CKD, and hypertension, compared with a matched hospitalized cohort.

Keywords: acute renal failure; blood pressure; children; chronic kidney disease; clinical epidemiology; dialysis; end stage kidney disease; hypertension; mortality; pediatric nephrology.

Graphical abstract

Figure 1.

Cumulative probability of kidney failure or death among dialysis-treated AKI survivors versus comparators. Dialysis-treated AKI survivors experienced kidney failure or death sooner post-discharge.

Figure 2.

Cumulative probability of MAKE among dialysis-treated AKI survivors versus comparators. MAKE was defined as a composite of all-cause mortality, kidney failure, or de novo CKD. Dialysis-treated AKI survivors experienced MAKE sooner post-discharge.

Figure 3.

Cumulative probability of de novo CKD among dialysis-treated AKI survivors versus comparators. “De novo” CKD was defined as a new diagnosis of CKD postdischarge in an individual without a diagnostic code for CKD during a 5-year lookback period before index hospitalization. Dialysis-treated AKI survivors experienced de novo CKD sooner post-discharge.

Figure 4.

Cumulative probability of de novo hypertension among dialysis-treated AKI survivors versus comparators. “De novo” hypertension was defined as a new diagnosis of hypertension postdischarge in an individual without a diagnostic code for hypertension during a 5-year lookback period before index hospitalization. Dialysis-treated AKI survivors experienced de novo hypertension sooner post-discharge.