Compare and contrast the utility of the following in the assessment of acute kidney injury in a critically ill patient:
• Creatinine clearance
• Serum creatinine
• Urine output measurements
• Novel biomarkers
• Gives estimation of Glomerular Filtration Rate (GFR).
• Requires timed urine collection (usually 24 hours)
• Accuracy may be limited due to creatinine secretion, thus overestimating
GFR, and incomplete urine collection.
• Assumes steady state in GFR, which may not be the case in acute renal failure.
• Determining exact GFR is rarely clinically necessary.
• Simple to measure and widely available.
• Specific for renal function.
• Indicator of GFR based upon constant production from muscle creatine and relatively constant renal excretion rate.
• Production may be increased by trauma, fever or immobilisation.
• Decreased in individuals with small stature cachexia, reduced muscle mass
(eg muscle disease, amputations)
• Decreased production may occur in liver disease because of decreased hepatic conversion of creatine to creatinine, decreased dietary protein intake, muscle wasting and increased renal tubular secretion of creatinine.
• May be influenced by volume of distribution changes in critically ill patients
• Simple to measure and widely available
• Not specific for renal function
• May be affected by liver disease, protein intake, catabolic state, volume status, upper gastrointestinal bleeding, and drug therapy – eg corticosteroids.
• Simple to measure and universally available.
• More sensitive to changes in renal function than biomarkers
• Non-specific – can have normal urine output despite severe acute renal failure
• Include a plasma panel (NGAL and cystatin C) and urine panel (NGAL, IL-8 and KIM-1)
• Represent sequential biomarkers and so have potential for timing the initial insult and assessing the duration of AKI and for predicting overall prognosis
• May also distinguish between various types and pathogeneses of AKI
• Potential for high sensitivity and specificity
• So far only tested in small studies and limited clinical situations and need further validation
This question would benefit from a tabulated answer.
A good resource for novel biomarkers is this systematic review in Nature.
This table is reproduced without any substantial alteration in the Required Reading section on renal injury biomarkers.
Parikh, Chirag R., et al. "Urinary interleukin-18 is a marker of human acute tubular necrosis." American Journal of Kidney Diseases 43.3 (2004): 405-414.
Devarajan, Peasad. "Neutrophil gelatinase-associated lipocalin (NGAL): a new marker of kidney disease." Scandinavian Journal of Clinical & Laboratory Investigation 68.S241 (2008): 89-94.
Bennett, Michael, et al. "Urine NGAL predicts severity of acute kidney injury after cardiac surgery: a prospective study." CLINICAL JOURNAL-AMERICAN SOCIETY OF NEPHROLOGY 3.3 (2008): 665.
Herget-Rosenthal, Stefan, et al. "Early detection of acute renal failure by serum cystatin C." Kidney international 66.3 (2004): 1115-1122.
Royakkers, Annick ANM, et al. "Serum and urine cystatin C are poor biomarkers for acute kidney injury and renal replacement therapy." Intensive care medicine 37.3 (2011): 493-501.
Coca, S. G., et al. "Biomarkers for the diagnosis and risk stratification of acute kidney injury: a systematic review." Kidney international 73.9 (2007): 1008-1016.
Shemesh, Ovadia, et al. "Limitations of creatinine as a filtration marker in glomerulopathic patients." Kidney Int 28.5 (1985): 830-838.
Waikar, Sushrut S., and Joseph V. Bonventre. "Creatinine kinetics and the definition of acute kidney injury." Journal of the American Society of Nephrology20.3 (2009): 672-679.
Bellomo, Rinaldo, et al. "Acute renal failure–definition, outcome measures, animal models, fluid therapy and information technology needs: the Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group." Critical care 8.4 (2004): R204.
Cockcroft, Donald W., and M. Henry Gault. "Prediction of creatinine clearance from serum creatinine." Nephron 16.1 (1976): 31-41.
Han, Won K., et al. "Kidney Injury Molecule-1 (KIM-1): a novel biomarker for human renal proximal tubule injury." Kidney international 62.1 (2002): 237-244.