Potential pitfalls in estimating renal injury by KDIGO, overcome by measuring creatinine clearance in acute kidney injury .

Acute kidney injury (AKI) is a common and serious condition frequently encountered in hospitalized patients. The severity of kidney injury is defined by the KDIGO criteria which attempt to establish the degree of renal impairment. These criteria do not measure actual creatinine clearance (K) but rather represents static measures of a dynamic process in AKI and are fraught with potential for false positives and negatives results. This paper, presented in an educational format, uses a new, unique, simple, and accurate method for estimating actual K in AKI utilizing urine creatinine excretion over an established time interval. Patient examples are provided to highlight the use of this method and its advantage over KDIGO, which has inherent shortcomings, while often incorrectly classifying the extent of renal injury in the patient with AKI. These cases highlight where KDIGO staging may over- or underestimate the actual degree of renal injury in patients with AKI. The present paper provides the practitioner with a useful tool to estimate real-time K in AKI with enough precision to predict the severity of the renal injury. It is the author's belief that this simple method, or others like it, improve on KDIGO for estimating the degree of renal impairment in AKI, and allow a more accurate estimate of K. Methods to measure creatinine clearance in AKI have the potential to improve care for patients with this condition.