In Reply to ‘Renal Replacement Therapy Dosing in Acute Kidney Injury’

Abstract

Jacobs and colleagues' observation1Jacobs F.M. Sztrymf B. Prat D. Renal replacement therapy dosing in acute kidney injury.Am J Kidney Dis. 2012; 60: 327-328Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar that they attained a Kt/Vurea > 1.2 in only 43% of dialysis sessions is consistent with numerous other studies. Jacobs et al report that they needed to increase the median treatment duration to nearly 5 hours with a median blood flow of 260 mL/min in order to achieve a median Kt/Vurea > 1.2. In the Veterans Administration/National Institutes of Health Acute Renal Failure Trial Network (ATN) Study, in which the delivered dose of therapy was monitored intensively, the median Kt/Vurea after the first treatment was slightly greater than 1.3 per treatment.2Palevsky P.M. Zhang J.H. O'Connor T.Z. et al.Intensity of renal support in critically ill patients with acute kidney injury.N Engl J Med. 2008; 359: 7-20Crossref PubMed Scopus (1332) Google Scholar To achieve this, the mean blood flow was substantially greater (360 mL/min) than that reported by Jacobs et al, although the median treatment time was shorter (4 hours).2Palevsky P.M. Zhang J.H. O'Connor T.Z. et al.Intensity of renal support in critically ill patients with acute kidney injury.N Engl J Med. 2008; 359: 7-20Crossref PubMed Scopus (1332) Google Scholar Dialysis delivery can vary considerably from treatment to treatment, given frequent issues such as catheter dysfunction and hemodynamic instability in patients with acute kidney injury. We therefore agree with Jacobs et al that real-time assessment of dialysis delivery provides a distinct advantage over retrospective assessment using Kt/Vurea or urea reduction ratio. We would caution, however, that the reliability of ionic dialysance for real-time monitoring of dialysis dose requires determining total body water reliably, a difficult task in this population. At this time it is unclear if ionic dialysate Kt/Vurea is equivalent to measured Kt/Vurea, and the 2 methods should not be used interchangeably without additional validation studies in the critically ill population.3Serra Cabanas N. Barros Freiria X. Garro Martinez J. et al.The monitoring of dialysis dose by ionic dialysance-based Kt reveals less dialysis adequacy than Kt/Vurea based measurement in critically ill patients with acute renal failure.Nefrologia. 2010; 30: 232-235PubMed Google Scholar Furthermore, standardization among different ionic dialysance monitors to ensure uniformity of measurements has not been completed.4Maduell F. Vera M. Arias M. et al.Influence of ionic dialysance monitor on Kt measurements in hemodialysis.Am J Kidney Dis. 2008; 52: 85-92Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar Thus, if real-time monitoring is utilized in the management of acute kidney injury, it should be combined with conventional urea-based assessment of dialysis dose until more data are available. Financial Disclosure: Dr Vijayan is a consultant for Astute Medical and receives research support from Cytopherx Inc and B. Braun. Dr Palevsky is a consultant for Sanofi-Aventis and Cytopherx Inc and receives research support from Spectral Diagnostics Inc. Renal Replacement Therapy Dosing in Acute Kidney InjuryAmerican Journal of Kidney DiseasesVol. 60Issue 2PreviewWe read with interest the review by Vijayan and Palevsky concerning renal replacement therapy (RRT) dosing in acute kidney injury (AKI).1 The authors state that intermittent hemodialysis treatment can be provided every other day if the per-session Kt/Vurea is at least 1.2. This proposition is endorsed by the International Consensus Conference in Intensive Care Medicine in their official statement on the prevention and management of AKI in intensive care units.2 The recently published KDIGO (Kidney Disease: Improving Global Outcomes) Clinical Practice Guideline for Acute Kidney Injury3 recommends achieving a Kt/Vurea of 3.9 per week. Full-Text PDF