A16(Th)
ACUTE KIDNEY INJURY (AKI) INVESTIGATION AND MANAGEMENT IN THE
INTENSIVE CARE UNIT (ICU): A SURVEY OF CURRENT UK PRACTICE
Jones, S, Devonald, M
Nottingham Renal and Transplant Unit, Nottingham University Hospitals NHS Trust
BACKGROUND: AKI occurs in up to 67% of critically ill patients and on average 5-6% of all ICU
patients with AKI require renal replacement therapy (RRT). In view of the apparent variability in
management of some aspects of AKI in the ICU, we surveyed current UK practice. We were
particularly interested in preferred mode of RRT, initiation and discontinuation criteria. We enquired
about threshold for nephrology referral and whether ICU staff were familiar with the 2009 NCEPOD
report on AKI (which recommended that nephrologists should be more closely involved in managing
critically ill patients requiring RRT).
METHODS: An on-line survey was distributed to all UK general adult ICUs between December
2009 and May 2010. Units were identified using the Critical Care Directory and all were contacted by
telephone. We asked about how AKI is diagnosed, staged, investigated and managed, including
details of RRT provided.
RESULTS: 188/233 ICUs (80%) started the survey and 167 (72%) completed it. CVVH is the most
frequently used form of RRT (56%) followed by CVVHDF (37%). Intermittent haemodialysis (IHD)
is used by only 5% units. CRRT is managed exclusively by intensivists in 94% units, whereas IHD is
managed predominantly by nephrologists (57%). The most frequently used criteria for initiating RRT
are hyperkalaemia, fluid overload and pH (acidaemia). 66% of respondents have a lower threshold for
commencing RRT in patients with severe sepsis. A satisfactory or improving urine output is the most
commonly used indication for discontinuing RRT followed by normalisation of pH.
73% of units have a standard protocol for RRT, with 35 mL/kg/h the most frequently used dose of
CVVH in these protocols (59%). Only 51% of units assess the delivered dose of RRT, usually by
regular measurement of serum urea and creatinine.
In over 40% units a nephrologist is never or only rarely consulted about patients with AKI. 88% of
units request nephrology input where primary renal disease is suspected. Only 19% of respondents
routinely use the AKIN or RIFLE criteria to stage and risk stratify their patients with AKI. 56% of
respondents always request a renal tract ultrasound scan but only 46% have 24 hour access to a renal
ultrasound scanning service.
CONCLUSION: AKI is a common problem in critically ill patients yet there is considerable
variation in how it is investigated and managed in UK ICUs. This is probably attributable in part to
the paucity of evidence relating to optimal management of AKI, including details of RRT modality
and prescription. Nephrologists appear to have little involvement in management of critically ill
patients with AKI. The internationally accepted and validated RIFLE and AKIN staging systems are
not widely used in UK ICUs at present and a significant proportion of ICU staff are not familiar with
NCEPOD recommendations on management of AKI.