A risk, injury, failure, loss, and end-stage renal failure score-based trigger for renal replacement therapy and survival after cardiac surgery

J Crit Care. 2012 Oct;27(5):488-95. doi: 10.1016/j.jcrc.2012.02.008. Epub 2012 Apr 3.


Purpose: It is controversial whether all critically ill patients with risk, injury, failure, loss, and end-stage renal failure (RIFLE) F class acute kidney injury (AKI) should receive renal replacement therapy (RRT). We reviewed the outcome of open heart surgery patients with severe RIFLE-F AKI who did not receive RRT.

Materials and methods: We identified all patients with AKI after cardiac surgery over 4 years and obtained baseline characteristics, intraoperative details, and in-hospital outcomes. We analyzed physiologic and biochemical features at RRT initiation or at peak creatinine if no RRT was provided.

Results: We reviewed 1504 patients. Of these, 137 (9.1%) developed postoperative AKI with 71 meeting RIFLE-F criteria and 23 (32.4% of RIFLE-F cases) not receiving RRT. Compared with RRT-treated RIFLE-F patients, "no-RRT" patients had lower Acute Physiology and Chronic Health Evaluation III scores, less intra-aortic balloon pump requirements, shorter intensive care stay, and a trend toward lower mortality. At peak RIFLE score, their urinary output, arterial pH, and Pao(2)/fraction of inspired oxygen ratio were all significantly higher. Their serum creatinine was also higher (304 vs 262 μmol/L; P = .02). Only 3 RIFLE-F no-RRT patients died in-hospital. Detailed review of cause and mode of death was consistent with non-RRT-preventable deaths. In contrast, 27 patients with RIFLE-R or RIFLE-I class received RRT. Compared with RRT-treated RIFLE-F patients, such RIFLE-R or RIFLE-I treated patients had a more severe presentation and higher mortality (51.8% vs 29.2%; P = .02).

Conclusions: After cardiac surgery, RRT was typically applied to patients with the most severe clinical presentation irrespective of creatinine levels. A RIFLE score-based trigger for RRT is unlikely to improve patient survival.

MeSH terms

  • Acute Kidney Injury / diagnosis
  • Acute Kidney Injury / mortality
  • Acute Kidney Injury / therapy*
  • Aged
  • Aged, 80 and over
  • Blood Chemical Analysis
  • Cardiac Surgical Procedures*
  • Creatinine / blood
  • Critical Illness
  • End Stage Liver Disease / diagnosis
  • End Stage Liver Disease / mortality
  • End Stage Liver Disease / therapy*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Patient Acuity*
  • Renal Replacement Therapy / methods*


  • Creatinine