Predictors of progression to chronic dialysis in survivors of severe acute kidney injury: a competing risk study

Abstract

BackgroundSurvivors of acute kidney injury are at an increased risk of developing irreversible deterioration in kidney function and in some cases, the need for chronic dialysis. We aimed to determine predictors of chronic dialysis and death among survivors of dialysis-requiring acute kidney injury.MethodsWe used linked administrative databases in Ontario, Canada, to identify patients who were discharged from hospital after an episode of acute kidney injury requiring dialysis and remained free of further dialysis for at least 90 days after discharge between 1996 and 2009. Follow-up extended until March 31, 2011. The primary outcome was progression to chronic dialysis. Predictors for this outcome were evaluated using cause-specific Cox proportional hazards models, and a competing risk approach was used to calculate absolute risk.ResultsWe identified 4 383 patients with acute kidney injury requiring temporary in-hospital dialysis who survived to discharge. After a mean follow-up of 2.4 years, 356 (8%) patients initiated chronic dialysis and 1475 (34%) died. The cumulative risk of chronic dialysis was 13.5% by the Kaplan-Meier method, and 10.3% using a competing risk approach. After accounting for the competing risk of death, previous nephrology consultation (subdistribution hazard ratio (sHR) 2.03; 95% confidence interval (CI) 1.61-2.58), a history of chronic kidney disease (sHR3.86; 95% CI 2.99-4.98), a higher Charlson comorbidity index score (sHR 1.10; 95% CI 1.05-1.15/per unit) and pre-existing hypertension (sHR 1.82; 95% CI 1.28-2.58) were significantly associated with an increased risk of progression to chronic dialysis.ConclusionsAmong survivors of dialysis-requiring acute kidney injury who initially become dialysis independent, the subsequent need for chronic dialysis is predicted by pre-existing kidney disease, hypertension and global comorbidity. This information can identify patients at high risk of progressive kidney disease who may benefit from closer surveillance after cessation of the acute phase of illness.

Outcomes of renal function in elderly patients with acute kidney injury

“…Our analysis suggests that BMI, baseline eGFR, low MAP, low prealbumin level, hypoalbuminemia, oliguria, BUN level, and more severe AKI stage were independent risk factors associated with death or renal nonrecovery. Other studies have identified advanced age, preexisting diabetes mellitus, decreased baseline eGFR,27 higher Charlson comorbidity index score,28 or hypomagnesemia23 as risk factors for renal nonrecovery in AKI survivors. Following a community-based study of patients older than 65 years, Sesso et al found a relationship between the rate of decline in eGFR with age and baseline eGFR, a result similar to that observed by Collins et al29,30 In contrast, Schiffl did not find any prognostic indicators related to partial recovery (defined as SCr >115 µmol/L at hospital discharge) when analyzing 226 critically ill patients with previous normal RF who had AKI requiring dialysis 25.…”

Promoting Kidney Function Recovery in Patients with AKI Requiring RRT

“…In summary, data from large cohorts suggest that approximately one of every 12 survivors of AKI-D who become dialysis independent will require long-term dialysis within 3-5 years (39,40). Increased risk of ESRD occurs regardless of baseline CKD status.…”

“…The risk of ESRD after AKI-D after early dialysis independence is substantial, ranging from 8% to 21% of survivors (12,39). A large cohort of 4383 patients with AKI-D who were dialysis free for .90 days was analyzed for risk of subsequent ESRD (defined as dialysis requirement for at least 90 days).…”

“…Of these, 8% (n5356) developed ESRD after a median follow-up of 2.4 years; of note, 34% (n51475) of the cohort died during the follow-up period. Risk factors for return to dialysis included preexisting CKD, hypertension, and comorbidities (39). In another large matched cohort study, 4869 patients with AKI-D who were alive and dialysis free at 30 days had a 2.4 higher adjusted risk of developing ESRD at a mean followup of 3 years compared with 4869 matched controls (12).…”

Long-term Sequelae from Acute Kidney Injury: Potential Mechanisms for the Observed Poor Renal Outcomes

“…The authors not only demonstrated that the risk of AKI rose cumulatively with worsening CKD and increased proteinuria but that this risk continued post-AKI with an increased chance of reaching the combined endpoint of ESRF or doubling of the serum creatinine. Harel et al followed survivors of dialysis-dependent AKI who had recovered renal function [17]. They showed that preexisting CKD (HR 3.86; 95% CI 2.99-4.98), hypertension (HR 1.82; 95% CI 1.28-2.58) and a higher Charlson comorbidity index score (HR 1.10; 95% CI 1.05-1.15/per unit) were significantly associated with risk of progression to ESRF.…”