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 χ<sup>2</sup> or Fisher’s exact test. Kaplan-Meier plots were utilized to assess survival. Sample size determinations to aid future research were calculated utilizing χ<sup>2</sup> 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.

Meropenem pharmacokinetics in critically ill patients with or without burn treated with or without continuous veno‐venous haemofiltration

“…By implementing LBW as a covariate, we minimized the effect of weight attributed to fluid resuscitation or fluid loss via capillary leak in the burn population and provide a more uniform comparison between burn and surgical ICU patients. Regarding the decision to categorize the base model, it is important to note that CVVH is associated with a mortality benefit in burn patients with shock 38,39 . Although the subset of burn patients that benefit the most from CVVH is not firmly established, and results have not consistently achieved statistical significance, CVVH has a large reported effect size (33% absolute reduction) in 28‐day mortality compared to historic controls.…”

“…Regarding the decision to categorize the base model, it is important to note that CVVH is associated with a mortality benefit in burn patients with shock. 38 , 39 Although the subset of burn patients that benefit the most from CVVH is not firmly established, and results have not consistently achieved statistical significance, CVVH has a large reported effect size (33% absolute reduction) in 28‐day mortality compared to historic controls. For this reason, CVVH is implemented early and aggressively in the burn population at the US Army Burn Center, including in patients with preserved renal function.…”

Extracorporeal Blood Purification in Burns: For Whom, Why, and How?

“…Burn patients do indeed commonly present with acute kidney injury (AKI), the frequency of which is reported to be as high as 30%, and related mortality as high as 80% [ 57 ]. Chung et al [ 58 ] recently reported in several cohorts that the application of renal replacement therapy in adult patients with severe burns and AKI was associated with a decrease in morbidity and mortality [ 59 ]. Animal studies in burn models also exhibit promising results with a significant removal of IL-1, IL-6, IL-10, and myoglobin by the Cytosorb TM hemoadsorptive column when performed for 6 h sessions during a 3 day period, even if no significant systemic or pulmonary reductions of cytokines were found [ 60 ].…”

Population Pharmacokinetic Modeling and Simulations of Imipenem in Burn Patients With and Without Continuous Venovenous Hemofiltration in the Military Health System

“…Traditionally, indications for the implementation of CRRT include the presence of severe acidosis, electrolyte disturbance, toxic ingestion, volume overload, or uremia 21–23 . Continuous venovenous hemofiltration (CVVH), one of the most common modalities of CRRT, has been correlated with improved clinical incomes and associated with decreased mortality rates in burn and critically ill patients with acute kidney injury (AKI) 24–28 . As such, there is generally a low threshold to initiate CVVH in the critically ill burn population.…”

“… 21 , 22 , 23 Continuous venovenous hemofiltration (CVVH), one of the most common modalities of CRRT, has been correlated with improved clinical incomes and associated with decreased mortality rates in burn and critically ill patients with acute kidney injury (AKI). 24 , 25 , 26 , 27 , 28 As such, there is generally a low threshold to initiate CVVH in the critically ill burn population. CVVH allows for efficient metabolic solute CL and ultrafiltration of fluid; however, it imposes significant challenges on drug dosing, as factors beyond extracorporeal drug removal need to be accounted for, to include residual kidney function and changes in V d and protein binding.…”