Simple and readily available patient characteristics predicts death and dialysis dependence in critically ill patients with severe acute kidney injury

MedicalResearch.com Interview with:

Raghavan Murugan MD, MS, FRCP, FCCP Associate Professor of Critical Care Medicine and Clinical and Translational Science Core Faculty, Center for Critical Care Nephrology, CRISMA Center, Raghavan Murugan MD, MS, FRCP, FCCP
Associate Professor of Critical Care Medicine and Clinical and Translational Science
Core Faculty, Center for Critical Care Nephrology, CRISMA Center,

John Kellum, MD Professor and Vice Chair for Research Director, Bioengineering and Organ Support Program, CRISMA Center Director, Center for Assistance in Research using eRecord (CARe)John Kellum, MD
Professor and Vice Chair for Research
Director, Bioengineering and Organ Support Program, CRISMA Center
Director, Center for Assistance in Research using eRecord (CARe)

Department of Critical Care Medicine
University of Pittsburgh Pittsburgh, PA

Medical Research: What is the background for this study? What are the main findings?

Response: In our prior studies, we found that nearly one-half of critically ill patients in the intensive care unit who receive dialysis die by 2 months after acute illness and more than one-third of surviving patients are dialysis dependent. We sought to examine whether simple patient characteristics and inflammatory biomarkers predicted death and non-recovery of kidney function after severe acute kidney injury.

We found that a combination of four simple and readily available patient characteristics including older age, lower mean arterial pressure, need for mechanical ventilation, and higher serum bilirubin levels predicted death and dialysis dependence. Higher plasma concentration of interleukin (IL)-8 in combination with the clinical characteristics also increased risk prediction. To our knowledge, this study is the first large study to examine risk prediction for outcomes after severe acute kidney injury using a panel of biomarkers in a large cohort of critically ill patients receiving dialysis.

Medical Research: What should clinicians and patients take away from your report?

Response: Our findings have important implications for patients and clinicians. First, the four clinical characteristics along with plasma IL-8 could be used to estimate patient prognosis and clinical decision-making by nephrologists and intensivists. For instance, the clinical variables and IL-8 marker levels measured on the day when dialysis initiation is being considered by a clinician could be useful to better inform patients and families about prognosis. Because patients who are older, are mechanically ventilated, and have lower mean arterial pressure, high bilirubin, and IL-8 levels, are likely to have worse outcomes, they may not wish to undergo dialysis and clinicians may treat those patients accordingly. Second, early prediction of renal recovery is likely to be helpful with regard to post-discharge planning by nephrologists after critical illness and monitoring for subsequent progression to chronic kidney disease and end-stage renal disease in patients who are unlikely to have complete renal recovery.

Medical Research: What recommendations do you have for future research as a result of this study?

Response: First, although IL-8 is not yet used in clinical practice to treat patients with acute kidney injury, the assay is easy to perform and could easily be developed into a clinical test. Second, identification of a homogeneous group of patients using biomarker-guided risk assessment allows for examination of new interventions or interventions that have previously failed in clinical trials that included a heterogeneous population of patients with severe acute kidney injury. Third, although we did a cross-validation within our study, our findings require external validation before they can be applied to other patient populations with severe acute kidney injury.

Citation:

Biomarker Enhanced Risk Prediction for Adverse Outcomes in Critically Ill Patients Receiving RRT

Francis Pike, Raghavan Murugan, Christopher Keener, Paul M. Palevsky, Anitha Vijayan, Mark Unruh, Kevin Finkel, Xiaoyan Wen, John A. Kellum, and for the Biological Markers for Recovery of Kidney (BioMaRK) Study Investigators

CJASN CJN.09911014; published ahead of print June 5, 2015, doi:10.2215/CJN.09911014