Continuous venovenous hemofiltration in severely burned patients with acute kidney injury: a cohort study

INTRODUCTION: Acute kidney injury (AKI) is a common and devastating complication in critically ill burn patients with mortality reported to be between 80 and 100%. We aimed to determine the effect on mortality of early application of continuous venovenous hemofiltration (CVVH) in severely burned patients with AKI admitted to our burn intensive care unit (BICU). METHODS: We performed a retrospective cohort study comparing a population of patients managed with early and aggressive CVVH compared with historical controls managed conservatively before the availability of CVVH. Patients with total body surface area (TBSA) burns of more than 40% and AKI were treated with early CVVH and their outcomes compared with a group of historical controls. RESULTS: Overall, the 28-day mortality was significantly lower in the CVVH arm (n = 29) compared with controls (n = 28) (38% vs. 71%, P = 0.011) as was the in-hospital mortality (62% vs. 86%, P = 0.04). In a subgroup of patients in shock, a dramatic reduction in the pressor requirement was seen after 24 and 48 hours of treatment. Compared with controls (n = 19), significantly fewer patients in the CVVH group (n = 21) required vasopressors at 24 hours (100% vs 43%, P < 0.0001) and at 48 hours (94% vs 24%, P < 0.0001). In those with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), there was a significant increase from baseline in the partial pressure of arterial oxygen (PaO(2)) to fraction of inspired oxygen (FiO(2)) ratio at 24 hours in the CVVH group (n = 16, 174 ± 78 to 327 ± 122, P = 0.003) but not the control group (n = 20, 186 ± 64 to 207 ± 131, P = 0.98). CONCLUSIONS: The application of CVVH in adult patients with severe burns and AKI was associated with a decrease in 28-day and hospital mortality when compared with a historical control group, which largely did not receive any form of renal replacement. Clinical improvements were realized in the subgroups of patients with shock and ALI/ARDS. A randomized controlled trial comparing early CVVH to standard care in this high-risk population is planned.