Serum creatinine and the search for new biomarkers of acute kidney injury (AKI): the story continues

Abstract

AKI: the problem The term ‘ acute kidney injury ’ (AKI) currently identifi es a wide spectrum of clinical conditions ranging from a minimal elevation in serum creatinine levels to the requirement for renal replacement therapy. Therefore AKI includes both slight injury and/or a severe impairment in renal function, a condition formerly known as acute renal failure (ARF). AKI is a global problem which occurs less frequently in the community than in the hospital, where is commonly found on pediatric, oncology and surgical wards, with the highest frequency in the intensive care unit (ICU). It has been estimated that severe AKI requiring admission to an ICU occurs in about 10 patients per 100,000 per year, whereas AKI affects up to 30 % of all ICU admissions usually as a manifestation of a multi-organ failure syndrome (1) . Patients with chronic kidney disease (CKD) are particularly susceptible to AKI and AKI in turn may act as a cause of new-onset CKD or a promoter of underlying CKD progression. A rough estimate of the yearly incidence of end stage renal disease (ESRD) due to AKI is about 0.3 per 100,000 (2) , and CKD can be detected in an average of 30 % of AKI survivors (3) . Irrespective of its nature, AKI affects both short-term and long-term cardiovascular outcomes and the in-hospital mortality currently remains dramatic (4) . The early identifi cation and correct diagnosis is therefore crucial to establish appropriate therapeutic measures in a timely manner, saving costs and improving patients ’ outcomes and quality of life.