CONTINUOUS RENAL REPLACEMENT THERAPY UTILIZATION AND MORTALITY IN CRITICALLY ILL ADULTS WITH ACUTE KIDNEY INJURY

Introduction:

Despite the growing availability of renal replacement therapy (RRT) in the ICU, mortality rates in patients with acute kidney injury (AKI) requiring RRT remain high. Continuous RRT (CRRT) has been the preferred modality for hemodynamically unstable patients with AKI and those with severe fluid overload in the ICU. However, the association between CRRT volume and outcomes is not clear. We hypothesized that CRRT utilization rates are associated with survival rates among critically ill patients with AKI.

Methods:

We used the Premier PINC AI Healthcare Database to study adult critically ill patients with AKI requiring RRT in U.S. hospitals offering both CRRT and IHD who were discharged between January 1, 2018, and June 30, 2021. We categorized hospitals based on their use of CRRT, defined as the proportion of patients receiving CRRT among all patients requiring RRT in the ICU, and then divided them into quartiles of CRRT use (with cutoffs at 8%, 17%, and 31.5%). Using Cox regression, we assessed the impact of CRRT utilization on hospital mortality by day 90, while controlling for demographics, comorbidities, severity of illness, processes of care, and other hospital characteristics.

Results:

A total of 49,685 patients requiring RRT were analyzed. The average age was 63 years, 68% were male, and 37% received CRRT as the initial RRT modality. The mean CRRT utilization rate per facility was 21% (range: >0 - 94%). CRRT utilization by quartile was 21%, 18%, 24%, and 37% for the first, second, third, and fourth quartiles, respectively. Patients from hospitals with the highest quartile of CRRT utilization had higher incidences of septic shock (52% vs. 48%), COVID-19 (15% vs. 11%), APR-DRG Severity of Illness Extreme score (93% vs. 88%), mechanical ventilation (76% vs. 64%), and ECMO (4% vs. 0.7%) compared to the lowest quartile (Table 1). Crude hospital mortality was higher among patients in the highest quartile (first quartile: 30%; second quartile: 31%; third quartile: 34%; fourth quartile: 37%; p< 0.001). In the multivariable analysis, patients from hospitals with a CRRT utilization rate above the median had a lower risk of mortality (aHR = 0.90, 95% CI: 0.87-0.93, p < 0.001). Similar results were found in quartile analysis, showing lower mortality risks for the third (aHR = 0.93, 95% CI: 0.89-0.98, p = 0.007) and fourth (aHR = 0.85; 95% CI: 0.81-0.89, p < 0.001) quartiles compared to the first quartile (Figure 1). A dose-response relationship between higher CRRT utilization and lower adjusted mortality was observed in subgroups of severe sepsis, non-COVID patients, and other sensitivity analyses.

Conclusions:

Patients with AKI requiring RRT at hospitals with higher CRRT utilization rates had significantly lower risk-adjusted mortality compared with hospitals with lower CRRT utilization rates. Further research is needed to understand contributing factors such as RRT care processes, quality assurance, and human factors that could be modifiable and may have contributed to the observed relationship.

I have potential conflict of interest to disclose.
This study was funded by Baxter Healthcare Corporation. However, the Authors retain full responsibility for its content. RM and JAN received consultant fees from Baxter for this study. JE, KH, CP, and DBL are full-time employees of Baxter International with ownership interests.

I did not use generative AI and AI-assisted technologies in the writing process.