['Optimal management of acute kidney injury (AKI) remains controversial, particularly with respect to acutely unwell patients in the intensive care unit (ICU). This is likely to be attributable to the currently poor evidence base. Attempts to introduce guidance and consistency have been made over recent years, such as the AKI Network (AKIN) staging system and, in the UK, recommendations from the 2009 National Confidential Enquiry into Patient Outcome and Death (NCEPOD) report into AKI. We wished to ascertain how AKI is investigated and managed in intensive care units in the UK, and whether these recent initiatives have made any difference to clinical practice.', 'This is an online survey of all general adult UK ICUs between December 2009 and May 2010.', 'One hundred and eighty-eight out of two hundred and thirty-three units (80%) started the survey; 167 (72%) completed it. Only 19.2% of respondents routinely use AKIN or Risk, Injury, Failure, Loss, End-stage kidney disease (RIFLE) criteria for diagnosis and staging of AKI. A nephrologist is never or rarely consulted about patients with AKI in over 40% of the units. Only 46.4% have 24-h access to a renal ultrasound service. Continuous venovenous haemofiltration (CVVH) is the most commonly used form of renal replacement therapy (RRT) but intermittent haemodialysis (IHD) is used infrequently. Continuous RRTs (CRRTs) are managed almost exclusively by intensivists, whereas IHD is managed predominantly by nephrologists. The most frequently used criteria for initiating RRT are hyperkalaemia, fluid overload and pH. Most units have a standard RRT protocol and 35 mL/kg/h is the most frequently prescribed dose of CVVH. Only 51% of the units assess the delivered dose of RRT.'] Is how acute kidney injury investigated and managed in UK intensive care units -- a survey of current practice?