Fluid balance as a biomarker: impact of fluid overload on outcome in critically ill patients with acute kidney injury

Sean M Bagshaw¹, Patrick D Brophy², Dinna Cruz³ and Claudio Ronco³

¹Division of Critical Care Medicine, Faculty of Medicine and Dentistry, University of Alberta, 3C1.12 Walter C Mackenzie Centre, 8440-112 ST NW, Edmonton, T6G 2B7, Canada

²Division of Nephrology, Hypertension, Dialysis and Transplantation, Department of Pediatrics, 285 Newton Road, 1269-A CBRB, Iowa City, Iowa, 52242, USA

³Department of Nephrology Dialysis & Transplantation, San Bortolo Hospital, Viale Rodolfi 37, 36100 Vicenza, Italy

author email corresponding author email

Critical Care 2008, 12:169doi:10.1186/cc6948


Published:	24 July 2008

See related research by Payen et al., http://ccforum.com/content/12/3/R74

Abstract

Fluid therapy is fundamental to the acute resuscitation of critically ill patients. In general, however, early and appropriate goal-directed fluid therapy contributes to a degree of fluid overload in most if not all patients. Recent data imply that a threshold may exist beyond which, after acute resuscitation, additional fluid therapy may cause harm. In patients with acute kidney injury and/or oliguria, a positive fluid balance is almost universal. Few studies have examined the impact of fluid balance on clinical outcomes in critically ill adults with acute kidney injury. Payen and coworkers, in a secondary analysis of the SOAP (Sepsis Occurrence in Acutely Ill Patients) study, now present evidence that there is an independent association between mortality and positive fluid balance in a cohort of critically ill patients with acute kidney injury. In this commentary, we discuss these findings within the context of prior literature and propose that assessment of fluid balance should be considered as a potentially valuable biomarker of critical illness.