This was the subject of Question 12 from the first paper of 2012. It was answered to a satisfactory standard by only 2% of the candidates.
The classification system separates renal failure into 5 categories:
Category |
GFR criteria | Urine output criteria |
Risk |
Creatinine x 1.5 | u/o < 0.5ml/kg/hr x 6 hrs |
Injury |
Creatinine x 2 | u/o < 0.5ml/kg/hr x 12 hrs |
Failure |
Creatinine x 3 | u/o < 0.3ml/kg/hr x 24 hrs |
Loss |
Complete loss of function > 4 weeks | |
End-stage |
Complete loss of function > 3 months |
The Acute Dialysis Quality Initiative formulated this classification to fill a certain vacuum in renal failure research. The paper was published by Ronco Bellomo and Kellum in 2004. Good dissections are available from Life In The Fast Lane and from the ADQI people. The point of this system was to predict mortality and hospital stay from easily measured parameters, so as to be able to compare the efficacy of interventions.
Lopes et al have published "a critical and comprehensive review" of the RIFLE and AKIN criteria in 2012. This summary owes much to their article.
Bellomo, Rinaldo, et al. "Acute renal failure–definition, outcome measures, animal models, fluid therapy and information technology needs: the Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group." Critical care 8.4 (2004): R204.
Cruz, Dinna N., Zaccaria Ricci, and Claudio Ronco. "Clinical review: RIFLE and AKIN–time for reappraisal." Critical care 13.3 (2009): 211.
Hoste, Eric AJ, and John A. Kellum. "Acute kidney injury: epidemiology and diagnostic criteria." Current opinion in critical care 12.6 (2006): 531-537.
Chertow, Glenn M., et al. "Acute kidney injury, mortality, length of stay, and costs in hospitalized patients." Journal of the American Society of Nephrology16.11 (2005): 3365-3370.
Lopes, José António, and Sofia Jorge. "The RIFLE and AKIN classifications for acute kidney injury: a critical and comprehensive review." Clinical Kidney Journal 6.1 (2013): 8-14.