Outcome of acute kidney injury in severe burns: a systematic review and meta-analysis

The main objective of this review was to analyse the prevalence and outcome of acute kidney injury (AKI) in patients with severe burn injury. AKI is a common complication in patients with severe burn injury and one of the major causes of death (often combined with other organ dysfunctions). Several definitions of AKI have been used, but the RIFLE 'consensus' classification is nowadays considered the gold standard, enabling a more objective comparison of populations. We performed a systematic literature search (1960-2009), involving PubMed, the Web of Science, the search engine Google (TM) and textbooks. Reference lists and the Science Citation Index search were also consulted. Attributable mortality was assessed by performing a meta-analysis. This search yielded 57 articles and abstracts with relevant epidemiologic data of AKI in the burn population. Of these, 30 contained complete mortality data of the burn and control population, which revealed a 3- to 6-fold higher mortality for AKI patients in univariate analysis, depending on the applied definition. When defined by the RIFLE consensus classification, AKI occurred in one quarter of patients with severe burn injury (median mortality of 34.9%), and when defined by the need for renal replacement therapy (RRT), AKI occurred in 3% (median mortality of 80%). The prevalence of AKI slightly increased, but AKI-RRT decreased. However, the outcome in both groups improved. Despite the wide variation of the analysed burn populations and definitions of AKI, this review clearly showed that AKI remains prevalent and is associated with increased mortality in patients with severe burn injury.