• 
• 

Three Part Question

In [patients presenting to the emergency department with acute renal failure] is it better to use the [RIFLE or AKIN score] to [predict prognosis]?

Clinical Scenario

A 70-year-old woman presents to the emergency department (ED) with confusion and collapse. You find her serum creatinine is 180 μmol/l and wonder which classification system you should use to determine her renal function and prognosis.

Search Strategy

Medline 1996 to July week 1 2011 and Embase 1947 to July 2011 using the OVID interface.
(RIFLE.mp) AND (acute kidney injury network.mp OR AKIN.mp)).

Search Outcome

The Medline search identified 36 potentially relevant papers and EMBASE identified 65 papers.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Ando et al, Japan, 2010	249 Japanese patients who received haemopoietic stem cell transplants	Retrospective cohort analysis	AUC ROC curve for predicting 100-day mortality in myeloblastic patients	RIFLE 0.65. AKIN 0.64	The urine output measures were not used in calculating the scores Small sample of select patients
			AUC ROC curve for predicting 100-day mortality in non-myeloblastic patients	RIFLE 0.77. AKIN 0.73
Bagshaw et al, 2008, Australia	120 123 Patients admitted to 57 ICU in Australia or New Zealand 2000–5	Retrospective large database analysis	AUC of ROC curve for prediction of inhospital mortality	RIFLE 0.66. AKIN 0.67	The urine output measures were not used in calculating the scores
			OR for death if any criteria fulfilled in score	RIFLE 3.3 (95% CI 3.2 to 3.4) . AKIN 3.1 (95% CI 3.0 to 3.3)
Chang et al, 2010, Japan	291 ICU patients, single centre, 2003–6	Retrospective chart review	AUC of ROC curve for prediction of inhospital mortality	RIFLE 0.74. AKIN 0.72	Small cohort
Englberger et al, 2011, USA	4836 Patients undergoing cardiac surgery	Retrospective chart review	AUC of ROC curve for 30-day mortality	RIFLE 0.80. AKIN 0.82	Retrospective analysis The urine output measures were not used in calculating the scores
			AUC of ROC curve for intubation >24 h	RIFLE 0.66. AKIN 0.67
Silva Júnior et al, 2011, Brazil	287 Patients diagnosed with leptospirosis at two infectious disease hospitals 1985–2008	Retrospective chart review	OR for death of patients assigned RIFLE ‘F’ or AKIN ‘3’	RIFLE 11.6 (95% CI 0.5 to 88.0). AKIN 12.8 (95% CI 1.6 to 96.8)	Unclear how long patients were followed up for Small select patient group
Haase et al, 2009, Italy	282 Patients undergoing cardiac surgery	Prospective study	AUC of ROC curve for prediction of inhospital mortality	RIFLE 0.91. AKIN 0.94	Small population
Joannidis et al, 2009, Austria	14 365 Patients from registry of 303 international ICU	Retrospective large database analysis	OR for inhospital mortality for patients designated RIFLE ‘F’ or AKIN ‘3’	RIFLE 3.0 (95% CI 2.7 to 3.4) .AKIN 3.0 (95% CI 2.6 to 3.4)	Limited urine output data
			AUC of ROC curve for prediction of inhospital mortality	RIFLE 0.84. AKIN 0.84
Lopes et al, 2008, Portugal	662 Patients admitted to a single ICU	Retrospective review	OR for prediction of inhospital mortality for any RIFLE criteria or any AKIN criteria	RIFLE 2.8 (95% CI 1.7 to 4.4). AKIN 3.6 (95% CI 2.1 to 6.0)	Retrospective study The urine output measures were not used in calculating the scores
			AUC of ROC curve for prediction of inhospital mortality	RIFLE 0.73. AKIN 0.75
Ostermann et al, 2011, UK	41 792 ICU patients from 22 ICU units in UK and Germany, 1989–99	Retrospective large database review	AUC of ROC curve for prediction of inhospital mortality	RIFLE 0.90. AKIN 0.84	The urine output measures were not used in calculating the scores
Robert et al, 2010, USA	24 747 Patients undergoing cardiac surgery in northern New England 2001–7	Large database review	OR for inhospital mortality	RIFLE ‘R’ 2.4 (95% CI 2.0 to 2.9) RIFLE ‘I’ 8.9 (95% CI 7.3 to 11.0) RIFLE ‘F’ 10.9 (95% CI 33.9 to 49.3) AKIN ‘1’ 3.1 (95% CI 2.6 to 3.8) AKIN ‘2’ 12.4 (95% CI 9.8 to 15.7) AKIN ‘3’ 43.8 (95% CI 36.2 to 52.9)	The urine output measures were not used in calculating the scores
			AUC of ROC curve for prediction of inhospital mortality	p Value for equity of ROC areas 0.369 (no difference in areas)
Yan et al, 2009, China	67 Patients at a single centre who received extracorporeal membrane oxygen support after cardiac surgery 2004–8	Retrospective chart review	OR for inhospital mortality	RIFLE ‘R’ 2.1 (95% CI 0.3 to 15.4) RIFLE ‘I’ 8.6 (95% CI 1.4 to 51.2) RIFLE ‘F’ 12.6 (95% CI 2.2 to 72.3) AKIN ‘1’ 2.7 (95% CI 0.3 to 30.8) AKIN ‘2’ 5.1 (95% CI 0.5 to 56.9) AKIN ‘3’ 30.8 (95% CI 3.3 to 287.2)	Select, small population
			AUC of ROC curve for prediction of inhospital mortality	RIFLE 0.74. AKIN 0.80

Comment(s)

No study has assessed the utility of either score in the ED. Most studies did not apply the urine output criteria, which would be more relevant to the ED population.

Clinical Bottom Line

Both the RIFLE and AKIN score are predictive of inpatient mortality, and appear to be equally as good.

References

1. Ando M, Mori J, Ohashi K, et al. A comparative assessment of the RIFLE, AKIN and conventional criteria for acute kidney injury after hematopoietic SCT. Bone Marrow Transplant 2010;45:1427–34.
2. Bagshaw S, George C, Bellomo R; for the ANZICS Database Management Committee. A comparison of the RIFLE and AKIN criteria for acute kidney injury in critically ill patients. Nephrol Dial Transplant 2008;23:1569–74.
3. Chang C, Lin C, Tian Y, et al. Acute kidney injury classification: comparison of AKIN and RIFLE criteria. Shock 2010;33:247–52.
4. Englberger L, Suri R, Li Z, et al. Clinical accuracy of RIFLE and Acute Kidney Injury Network (AKIN) criteria for acute kidney injury in patients undergoing cardiac surgery. Crit Care 2011;15:R16.
5. Silva Júnior G, Abreu K, Mota R, et al. RIFLE and Acute Kidney Injury Network classifications predict mortality in leptospirosis-associated acute kidney injury. Nephrology 2011;16:269–76.
6. Haase M, Bellomo R, Matalanis G, et al. A comparison of the RIFLE and Acute Kidney Injury Network classifications for cardiac surgery—associated acute kidney injury: a prospective cohort study. J Thorac Cardiovasc Surg 2009;138:1370–6.
7. Joannidis M, Metnitz B, Bauer P, et al. Acute kidney injury in critically ill patients classified by AKIN versus RIFLE using the SAPS 3 database. Intensive Care Med 2009;35:1692–702.
8. Lopes J, Fernandes P, Jorge S, et al. Acute kidney injury in intensive care unit patients: a comparison between the RIFLE and the Acute Kidney Injury Network classifications. Crit Care 2008;12:R110.
9. Ostermann M, Chang R. Challenges of defining acute kidney injury. Q J Med 2011;104:237–43.
10. Robert A, Kramer R, Dacey L, et al. Cardiac surgery-associated acute kidney injury: a comparison of two consensus criteria. Ann Thorac Surg 2010;90:1939–43.
11. Yan X, Jia S, Meng X, et al. Acute kidney injury in adult postcardiotomy patients with extracorporeal membrane oxygenation: evaluation of the RIFLE classification and the Acute Kidney Injury Network criteria. Eur J Cardiothorac Surg 2010;37:334–8.