Low-Risk ICU Patients Can Still Develop Acute Kidney Injury

MedicalResearch.com Interview with:
Florentina E. Sileanu BS
Center for Critical Care Nephrology and Clinical Research, Investigation, and Systems Modeling of Acute Illness Center
Departments of Critical Care Medicine and Department of Biostatistics,
University of Pittsburgh Graduate School of Public Health and
Dr. John A. Kellum, MD, MCCM
Professor of Medicine, Bioengineering and Clinical & Translational Science
Vice Chair for Research
Center for Critical Care Nephrology,
University of Pittsburgh School of Medicine
Pittsburgh, PA

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

Response: Acute Kidney Injury (AKI) affects millions of Americans each year resulting in increased short and long-term complications including need for dialysis and death. Many trials recruiting subjects at risk for AKI have focused on those with other (e.g. cardiovascular and respiratory) organ failures because these patients are at highest for AKI. However, patients without these conditions might not be at low-risk for AKI. We explored whether Acute Kidney Injury occurring as a single organ failure or occurring before other organ failures would be associated with the same outcomes as in sicker patients. Using a large, academic medical center database, with records from July 2000 through October 2008, we identified a “low-risk” cohort as patients without cardiovascular and respiratory organ failures defined as not receiving vasopressor support or mechanical ventilation within the first 24 hours of ICU admission. We were able to show that low-risk patients have a substantial likelihood of developing AKI and that the relative impact on mortality of AKI is actually greater for low-risk patients (OR, 2.99; 95% 2.62-3.41) than for high-risk patients (OR, 1.19; 95% 1.09-1.3).

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

Response: Prior studies have shown that most AKI in the critically ill occurs in the setting of multi-organ failure and thus, most efforts to understand and prevent AKI in the critically ill have focused on high-risk ICU patients, typically those with multi-organ failure. While this approach will identify the majority of patients developing AKI, it has two important shortcomings:

First, patients with isolated AKI or those with AKI as the first organ failure may be more amenable to therapy. While multi-organ failure has been the focus of intense research for over 30 years, no approved therapies exist. By contrast, isolated AKI might be more likely to be due to more specific and treatable conditions.

Second, AKI is sometimes the first manifestation of multi-organ failure and focusing only on patients with established organ failures involving systems other than the kidney will automatically result in late detection of AKI in these patients. Strategies aimed at preventing AKI should not exclude ICU patients without cardiovascular or respiratory organ failures.

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

Response: Opportunities for improvement in patient care exist with identification and management of low- and high-risk AKI patients. Automated clinical surveillance systems are effective for a variety of clinical conditions including the identification of sepsis, adverse drug reactions and more recently, AKI. These surveillance systems have assisted with faster identification of events compared to usual care that has been shown to improve short-term progression of AKI severity. Future studies are needed to determine the impact of clinical surveillance systems used to detect AKI on long-term recovery of renal function, as well as how these systems can be further refined to enhance the detection and management of AKI.
Citation:

AKI in Low-Risk versus High-Risk Patients in Intensive Care
lorentina E. Sileanu, Raghavan Murugan, Nicole Lucko, Gilles Clermont, Sandra L. Kane-Gill, Steven M. Handler, and John A. Kellum
CJASN CJN.03200314; published ahead of print November 25, 2014, doi:10.2215/CJN.03200314