CRD summary: This review investigated the effects of frusemide intake to prevent or treat acute renal failure. The authors' conclusion that frusemide is not effective in the prevention or treatment of acute renal failure in adults, and that high doses may be associated with an increased risk of ototoxicity, may be overstated given the small existing evidence base.

CRD commentary: The review addressed a clearly stated question which was supported by relevant inclusion and exclusion criteria. Several electronic databases were searched without language restrictions, but a funnel plot analysis revealed the possibility of publication bias (although, rather unusually, demonstrating the absence of published positive studies). The procedures used to select papers for inclusion in the review and to extract the data were likely to minimise the possibility of error or bias. The methodological quality of the included studies was assessed. Individual results were reported, and the authors assessed and discussed the potential impact of aspects of methodological quality. The quantitative analysis appeared appropriate and statistical heterogeneity was assessed.

However, meta-analyses for outcomes relating to in-hospital mortality and the proportion of persistent oliguric patients after treatment for acute renal failure included participants in the control group that had been counted more than once; this might have affected the results obtained. In addition, the authors' conclusions, which were largely based on small datasets from a small number of studies, may be overstated.