Relative Oliguria as a Risk Factor for Volume Overload in Critically Ill Children
Joseph Alge, MD, PhD, MS
BACKGROUND: Critically ill children are at increased risk of volume overload, a condition of excessive fluid in the body, due to obligate exposure to large amounts of intravenous fluids and a high incidence of acute kidney injury leading to impaired ability to excrete these fluids. Severe acute kidney injury sometimes can lead to a dramatic decrease in urine output, but most children experience a more subtle drop in urine output, known as relative oliguria, which leads to slow fluid accumulation and development of volume overload over the course of several days. GAP: Relative oliguria is a poorly defined concept, and the proposed study will develop a new framework for conceptualizing the adequacy of urine output, taking into account fluid intake and diuretic use. HYPOTHESIS: Our overarching hypothesis is that relative oliguria is an early and sensitive predictor of volume overload and related morbidity and mortality. METHODS: Critically ill children admitted to the pediatric intensive care unit at Texas Children’s Hospital will be prospectively enrolled in a cohort study, and we will test the ability of the urine output index, a novel concept of assessing urine output, and furosemide responsiveness to predict the development of volume overload and associated adverse outcomes within 7 days of admission. RESULTS: Pending IMPACT: The proposed study will provide pediatric intensivists with new tools to identify patients at risk of volume overload that will facilitate timely guidance of fluid management and prevention of this dreaded complication of critical illness.