The application of a new technique, based on differential measurements of pH, to determine urea concentration in patients of a dialysis center, is reported. Urea in plasma, whole blood or dialysis fluids is measured by an enzymatic reaction, with urease; the procedure, requiring 10 μL of sample, is simple, fast and correlates well with a reference spectrophotometric method, in the 0-300 mg/dL concentration range, according to the equation y = 1.0291 x - 0.0777; r = 0.9991; n = 73.
GotchF.A., SargentJ.A.A mechanistic analysis of the National Cooperative Dialysis Study (NCDS). Kidney Int1985; 28: 526–34.
2.
LowrieE.G., LairdN.M., ParkerT.F., and SargentJ.A.Effect of the haemodialysis Prescription on Patient Morbidity. New Engl J Med1981; 11: 1176–81.
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BorahM.F., SchoenfeldP.Y., GotchFA. Nitrogen Balance during Intermittent Dialysis Therapy of uraemia. Kidney Int1978; 14, 491–500.
4.
BlaggC.R.Acute complications associated with haemodialysis. In: DrukkerW., ParsonsF.M., MaherJ.F. eds. Replacement of Renal Function by Dialysis.The Hague: Martinus Nijhoff Publishers, 1983; 612.
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LuzzanaM., DossiG., MoscaA. Measurement of Glucose in Plasma by a Differential pH Technique. Clin Chem1983; 29/1, 80–5.
6.
RipamontiM., MoscaA., RovidaE. Urea, Creatinine, and Glucose determined in Plasma and Whole Blood by a Differential pH Technique. Clin Chem1984; 30, 556–9.
7.
CheungA.K., AlfordM.F., WilsonM.M., LeypoldtJ.K., HendersonL.W.Urea Movement across Erythrocyte Membrane during Artificial Kidney Treatment. Kidney Int1983; 23, 866–9.
