Review
Copyright ©2014 Baishideng Publishing Group Inc.
World J Cardiol. Sep 26, 2014; 6(9): 1006-1021
Published online Sep 26, 2014. doi: 10.4330/wjc.v6.i9.1006
Table 1 Definition and classification for acute kidney injury
Serum creatinine/GFR criteriaUrine output criteria
RIFLE classification
DefinitionSCr rise ≥ 1.5 times baseline or GFR decrease > 25% within 7 d
StagingR (Risk) SCr rise up to 2 times baseline or GFR decrease > 25%< 0.5 mL/kg per hour for ≥ 6 h
I (Injury) SCr rise up to 3 times baseline or GFR decrease > 50%< 0.5 mL/kg per hour for ≥ 12 h
F (Failure) SCr rise 3 times baseline or more or GFR decrease > 75% or absolute SCr ≥ 4 mg/dL with acute rise ≥ 0.5 mg/dL< 0.5 mL/kg per hour for ≥ 24 h or anuria ≥ 12 h
L (Loss) persistent AKI > 4 wk, need for RRT
E (ESRD) persistent loss > 3 mo, need for dialysis
AKIN classification
DefinitionSCr rise ≥ 1.5 times baseline or ≥ 0.3 mg/dL within 48 h
Staging1 SCr rise up to 2 times baseline or ≥ 0.3 mg/dL< 0.5 mL/kg per hour for ≥ 6 h
2 SCr rise up to 3 times baseline< 0.5 mL/kg per hour for ≥ 12 h
3 SCr rise 3 times baseline or more or absolute SCr ≥ 4 mg/dL with acute rise ≥ 0.5 mg/dL or need for RRT< 0.3 mL/kg per hour for ≥ 24 h or anuria ≥ 12 h
KDIGO classification
DefinitionSCr rise ≥ 1.5 times baseline within seven days or ≥ 0.3 mg/dL within 48 h or oliguria
Staging1 SCr rise up to 2 times baseline or ≥ 0.3 mg/dL
2 SCr rise up to 3 times baseline
3 SCr rise 3 times baseline or more or absolute SCr ≥ 4 mg/dL with acute rise ≥ 0.5 mg/dL or need for RRT
Table 2 Risk factors for acute kidney injury
PreoperativeIntraoperative
Patient relatedPatient related
Renal dysfunction/high SCr1Low venous compliance
Advanced ageLow systemic vascular resistance
Female genderAutoregulatory systems disturbances
NYHA FC IVReduced LVEF or CHFLow output syndrome(pressor/IABP need)
Left main CADType of surgery
Diabetes mellitusValvular
Poor glycemic controlRe do surgery
Peripheral vascular diseaseEmergency
COPD
Coexisting liver disease
Preoperative IABP
Pulmonary rales
Genetic predisposition
ModifiableProcedure related3
Extremes of SBP2On-pump cardiac surgery
Sepsis2Nonpulsatile flow on CPB
Medications (NSAID, ARB)Hypothermic CPB
Contrast dyeDeep hypothermic circulatory arrest
Duration of CPB (> 100-120 min)
Perfusion pressure
Hemodilution during CPB
Blood transfusion
Hemolysis
Embolism
Table 3 Potential preventive measures and pharmacological interventions in acute kidney injury
Preventive measures
Avoidance of nephrotoxic drugs
Angiotensin-converting enzyme inhibitors
Angiotensin receptor blockers
Hydration
Glycemic control
Maintenance of renal perfusion
Goal directed therapy
Ischemic preconditioning
Prevention of CI-AKI
Hydration
N-acetyl cysteine
Bicarbonate
Timing of surgery
Pharmacological interventions
Fenoldopam
Nesiritide
Sodium bicarbonate
Mannitol
Atrial natriuretic peptide
Brain-type natriuretic peptide
Early postoperative renal replacement therapy
Continuous renal replacement therapy
Ultrafiltration