Nephrocheck after cardiac surgery: Does it play a role in daily practice? A sequel of “Nephrocheck results should be corrected for dilution”

Abstract

Acute kidney injury is a well-recognized complication after cardiac surgery and significantly affects morbidity and mortality. Although the mechanisms of acute kidney injury are not fully understood, Nephrocheck (Astute Medical, San Diego, CA, USA) is a meter for early detection of acute kidney injury based on bedside urinalysis of two cell-cycle arrest biomarkers. However, considerable overlap in the AKIRisk^TM score of different RIFLE groups makes interpretation of the score uncertain. A possible reason for the overlap in the AKIRisk score between different RIFLE groups could be that the score is not corrected for dilution. We performed a pilot study to explore the applicability of the test in our daily practice. A total of 68 patients electively scheduled for cardiac surgery with at least two of the following inclusion criteria: age > 70 years, glomerular filtration rate <60 mL/min, left ventricular ejection fraction <41%, redo procedure and combined procedures have been enrolled in the study, and 25 of them developed acute kidney injury. We described the correlation between urine creatinine and Nephrocheck, all the samples with low Nephrocheck (<0.2) also have low urine creatinine, less than 50 mg/dL, detecting a potential diluted sample. In conclusion, in our daily practice AKIRisk score, together with an assessment of whether urine is diluted or concentrated can better discriminate between various degrees of acute kidney injury.