Urea^post dialysis/pre dialysis:SRto:Pt:Ser/Plas:Qn
urea^post dialysis/pre dialysis:srto:pt:ser/plas:qn
Urea^post dialysis/pre dialysis:Substance Ratio:To identify measures at a point in time:Serum/Plasma:Quantitative
urea^post dialysis/pre dialysis:substance ratio:to identify measures at a point in time:serum/plasma:quantitative