Dr Luk Ming Chi; CCMU, Alice Ho Miu Ling Nethersole Hospital
ABSTRACT
Study objectives: RIFLE criteria is widely used for the classification of acute kidney injury (AKI). Study on the outcome of AKI among patients admitted to intensive care unit of hospital in Hong Kong according to RIFLE classification is scarce. The aims of this study were therefore a) to study the prevalence of acute kidney injury defined by the maximum RIFLE classification within the first 24 h of ICU admission, b) to examine the progression between stages of the classification and c) to relate this classification to the length of stay and mortality in a cohort of critically- ill patients admitted to ICU of a local regional hospital.
Design: Retrospective single centre observational study
Setting: CCMU of Alice Ho Miu Ling Nethersole Hospital.
Patients: A total of 168 patients were examined.
Interventions: None
Measurements and Results: Acute kidney injury (AKI) occurred in 41% within the first 24 hours of ICU admission. A total of 20.2% patient achieved a maximum ‘RIFLE category Risk’ (RIFLE-R). ‘RIFLE category Injury’ (RIFLE-I) is 7.1% and ‘RIFLE category Failure’ (RIFLE-F) is 13.7%. The AKI group was sicker than the non-AKI group as reflected by the significantly higher mean APACHE II score on ICU admission. They also had more organ failure on ICU admission as evidence by the higher SOFA(non-renal) score. The progress of the 3 groups of patient was different. A high portion of patients in the RIFLE-R and in the RIFLE-I can have at least one grade improvement in their renal function, however, less than 10% of patients in the RIFLE-F can have one grade improvement. The presence of acute kidney injury was associated with a significant increase in hospital mortality and ICU mortality (39.1% vs 17.2%, p=0.001; 33.3% vs 9.1%, p< 0.001). The presence of AKI was associated with a 2.2- fold increase in mortality.
Conclusions: Our findings support the utility of the RIFLE criteria for classifying AKI and monitoring patient progress. Further study is warrant to confirm the findings.