The urea-to-creatinine ratio as an emerging biomarker in critical care: a scoping review and meta-analysis

Abstract

UCR elevations during critical illness potentially indicate muscle protein catabolism and the progression to persistent critical illness, and high levels at ICU admission could be associated with mortality. UCR increments during ICU stay may also indicate excessive exogenous dietary protein intake, overwhelming the body's ability to use it for whole-body or muscle protein synthesis. Dehydration, gastrointestinal bleeding, kidney and liver dysfunction, and renal replacement therapy may also influence UCR and are considered potential pitfalls when assessing catabolic phases of critical illness by UCR. Patient group-specific cut-off values are warranted to ensure its validity and application in clinical practice.