Acute Renal Failure -- Definition, Outcome Measures, Animal
Introduction: There is no consensus definition of acute renal failure (ARF) in critically ill patients. More than 30 different definitions have been used in the literature, creating much confusion and making comparisons difficult. Similarly, strong debate exists on the validity and clinical relevance of animal models of ARF; on choices of fluid management and of end-points for trials of new interventions in this field; and on how information technology can be used to assist this process. Accordingly, we sought to review the available evidence, make recommendations and delineate key questions for future studies.
Methods: We undertook a systematic review of the literature using Medline and PubMed searches. We determined a list of key questions and convened a 2-day consensus conference to develop summary statements via a series of alternating breakout and plenary sessions. In these sessions, we identified supporting evidence and generated recommendations and/or directions for future research.
Results: We found sufficient consensus on 47 questions to allow the development of recommendations. Importantly, we were able to develop a consensus definition for ARF. In some cases it was also possible to issue useful consensus recommendations for future investigations. We present a summary of the findings. (Full versions of the six workgroups' findings are available on the internet at http://www.ADQI.net)
Conclusion: Despite limited data, broad areas of consensus exist for the physiological and clinical principles needed to guide the development of consensus recommendations for defining ARF, selection of animal models, methods of monitoring fluid therapy, choice of physiological and clinical end-points for trials, and the possible role of information technology.

Acute renal failure (ARF) is a common complication of critical illness, which is associated with high mortality and has a separate independent effect on the risk of death. Despite several advances in treatment and in our understanding of the pathogenesis of ARF, many aspects in this field remain subject to controversy, confusion and lack of consensus. Important aspects beset by such problems include the definition of ARF; the choice, validity and relevance of animal models of ARF; and the choice regarding appropriate physiological and clinical end-points for trials of new treatments of ARF. They also include principles that should govern fluid management in patients with ARF and use of information technology to optimize all areas of patient care in this field.

The purpose of this consensus conference was to review the available evidence regarding optimal practice in these areas, make consensus-based recommendations and delineate key questions for future studies.