Vol.:(0123456789) 1 3 International Urology and Nephrology https://doi.org/10.1007/s11255-020-02601-z NEPHROLOGY - REVIEW Dialysis prescription in acute kidney injury: when and how much? Juan C. Badel 1  · Lautaro A. Garcia 1  · Manuel J. Soto‑Doria 2,3  · Carlos G. Musso 1,4 Received: 20 April 2020 / Accepted: 4 August 2020 © Springer Nature B.V. 2020 Abstract Acute kidney injury (AKI) constitutes a serious public health problem because of its very high cost and mortality rate, with an increasing incidence, phenomenon which is explained by the increasingly number of older patients sufering from several comorbidities admitted in the intensive care units. Despite the new AKI defnition and classifcation, the use of novel AKI biomarkers and modern technologies, as an attempt to achieve an early AKI detection and treatment, and consequently to better clinical outcomes, AKI mortality particularly in ICU patients remains persistently high. In the present article, the currently accepted concepts regarding dose and time of hemodialysis and peritoneal dialysis prescription in AKI patients have been reviewed. Keywords Dialysis · Dose · Prescription · Acute kidney injury Introduction According to KDIGO 2012, acute kidney injury (AKI) is defned as an abrupt renal function loss installed in hours or days, accompanied by an increase of serum creatinine (sCr) > 0.3 mg/dl compared to normal baseline value in the last 48 h, a serum creatinine increase of 1.5 times respect to previous sCr value in the last 7 days, and/or urine output lower than 0.5 cc/kg/h in the last 6 h [1–3]. In addition, AKI is currently classifed in three stages depending on the degree of sCr increase, and/or urine output rate reduction (Table 1) [3]. As mentioned above, sCr elevation and/or urine output reduction are currently used for diagnosing AKI; however, these parameters are not ideal AKI markers, since they do not elevate until 24–72 h after renal insult. Moreover, sCr value is also infuenced by various non-renal factors, such as age, race, sex, body weight, muscle metabolism, protein intake, which can obscure AKI diagnosis [4]. AKI is characterized by a transient increase in nitroge- nous wastes, hydro-electrolyte disorders, and impaired basic acid metabolism, and other clinical conditions which can lead the patient to need dialysis. Consequently, AKI consti- tutes a serious public health problem because of its very high cost and mortality rate, with an increasing incidence, phe- nomenon which is explained by the increasingly number of older patients sufering from several comorbidities admitted in the intensive care units (ICU). It is worth mentioning that AKI incidence in ICU is usually between 5 and 57%, being this wide range explained by the diferent AKI defnitions and diagnostic parameters used among ICUs. Moreover, AKI is also a major risk factor for developing chronic kidney disease (CKD), and end-stage renal disease (ESRD) [5, 6]. In a systematic review and meta-analysis that evalu- ated nine retrospective studies, Coca et al. showed that the adjusted risk for death among patients with AKI was 2.0 compared with those without AKI [7–10]. Mheta et al. reported that the overall mortality of AKI patients in ICU was 37%, while the mortality of more seri- ously ill patients who required renal replacement therapy (RRT) was around 50%, perhaps aggravated by the delay in starting this treatment [3, 11–14]. Despite the new AKI defnition and classifcation, the use of novel AKI biomarkers and modern technologies, as an attempt to achieve an early AKI detection and treatment, and consequently to better clinical outcomes, AKI mortality particularly in ICU patients remains persistently high. * Carlos G. Musso carlos.musso@hospitalitaliano.org.ar 1 Physiology Department, Instituto Universitario del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina 2 Clínica IMAT Oncomédica, Montería, Colombia 3 Universidad del Sinú, Montería, Colombia 4 Facultad de Ciencias de la Salud, Universidad Simón Bolívar, Barranquilla, Colombia