KIM-1 to Urinary Creatinine Ratio for Early Detection of AKI in Patients Undergoing Cardiopulmonary Bypass

Acute kidney injury (AKI) is a common serious complication among patients undergoing on-pimp cardiac surgery. Currently its diagnosis is based on the accumulation of nitrogen metabolism end products such as sCreat (serum creatinine) which is known to be late and unreliable marker for AKI for its levels are affected by different extrarenal variables. In recent years, several urinary markers of tubular damage have been proposed as more accurate alternatives to serum creatinine for the early detection of AKI in patients undergoing CPB (cardiopulmonary bypass). The objective of our study was to assess the performance characteristics of urinary KIM-1 measured 2-6 hours post surgery among adults undergoing CPB and to compare the predictive value of urinary KIM-1 with urinary KIM-1 to urinary creatinine ratio. ROC (receiver operator characteristics) -analysis revealed 2-6 hours post-CPB urinary KIM-1 AUC (area under the curve) of 0.84 (pless than0.001). For calculated urinary KIM-1 to urinary creatinine ratio the ROC analysis revealed an enhanced performance with AUC 0.85 (pless than0.001) giving AUC of 0.01. Using normalized values demonstrated a higher predictive value for urinary KIM-1 to urinary creatinine ratio for early detection of AKI compensating some of the shortcomings of absolute values determination related with effective extrarenal modifiers of the results.