Measuring glomerular filtration rate in the intensive care unit: no substitutes please.

Acute kidney injury (AKI), due to its increasing incidence, associated morbidity and mortality, and potential for development of chronic kidney disease with acceleration to end-stage renal disease, has become of major interest to nephrologists and critical care physicians. The development of biomarkers to diagnose AKI, quantify risk and predict prognosis is receiving considerable attention. Yet techniques to accurately assess functional changes within patients still rely on the use of an insensitive marker (creatinine), creatinine-based estimating equations and unreliable urinary tests. Therefore, it is critical that functional tests be developed and used in combination with biomarkers, thus allowing improved care in AKI and chronic kidney disease patient populations.