Acute Kidney Injury: It's not just the 'big' burns.

BACKGROUND: Acute Kidney Injury (AKI) complicates the management of at least 25% of patients with severe burns and is associated with long term complications. Most research focuses on the patients with more severe burns, and whether the same factors are associated with the development of AKI in patients with burns between 10 and 19% total body surface area (TBSA) is unknown. The aims of this study were to examine the incidence of, and factors associated with, the development of AKI in patients with %TBSA≥10, as well as the relationship with hospital metrics such as length of stay (LOS). METHODS: Retrospective medical record review of consecutive burns patients admitted to The Alfred Hospital, the major adult burns centre in Victoria, Australia. Demographic and injury details were recorded. Factors associated with AKI were determined using multiple logistic regression. RESULTS: Between 2010 and June 2014, 300 patients were admitted with burn injury and data on 267 patients was available for analysis. Median age was 54.5 years with 78% being male. Median %TBSA was 15 (IQR 12, 20). The AKI incidence, as measured by the RIFLE criteria, was 22.5%, including 15% (27/184) in patients with %TBSA 10-19. Factors associated with AKI included increasing age and %TBSA (OR 1.05 p<0.001) as well as increased surgeries (p<0.041) and a cardiac comorbidity (p<0.01). All patients with renal comorbidity developed AKI. In the %TBSA 10-19 cohort, only increasing age (OR 1.05 p<0.001) was associated with AKI. After accounting for confounding factors, the probability of discharge from hospital in Non-AKI group was greater than for the AKI patients at all time points (P<0.001). CONCLUSION: This is the first study to show an association between patients with %TBSA 10-19 and AKI. Given the association between AKI and complications, prospective research is needed to further understand AKI in burns with the aim of risk reduction.