Continuous Venovenous Hemofiltration is Associated with Improved Survival in Burn Patients with Shock: A Subset Analysis of a Multicenter Observational Study

Abstract

<b><i>Introduction:</i></b> Acute kidney injury (AKI) is associated with high mortality in burn patients. Previously, we reported that timely initiation of renal replacement therapy (RRT) with an individualized preference toward continuous modes at relatively higher than recommended doses has become standard practice in critically ill burn patients with AKI and is associated with a historically low mortality. The purpose of this cohort analysis was to determine if modality choice impacted survival in burn patients. <b><i>Methods:</i></b> After Institutional Review Board approval, a subset analysis was performed on de-identified data collected during a multicenter, observational study. All patients (<i>n</i> = 170) were 18 years or older, admitted with severe burn injuries and started on RRT. Comparisons were made utilizing χ² or Fisher’s exact test. Kaplan-Meier plots were utilized to assess survival. Sample size determinations to aid future research were calculated utilizing χ² test with a Yates Correction Factor. <b><i>Results:</i></b> Demographics and revised Baux were similar between groups. When continuous venovenous hemofiltration (CVVH) was compared to all other modalities, there was no statistically significant difference in survival (56 vs. 43%, <i>p</i> = 0.124). However, survival was significantly improved (54 vs. 37%, <i>p</i> = 0.032) in the subset of patients requiring vasopressors (<i>n</i> = 77). There was no statistically significant survival difference in patients with inhalation injury (38 vs. 29%, <i>p</i> = 0.638) or acute lung injury/acute respiratory distress syndrome (51 vs. 33%, <i>p</i> = 0.11). <b><i>Discussion/Conclusion:</i></b> Survival may be improved if CVVH is chosen as the preferred modality in burn patients with shock and requiring RRT. Differences in other subsets were promising, but analysis was underpowered. Further research should determine if modality choice provides survival benefit in any other subset of burn injury.