title: Determination of the acid-base status in blood of patients on chronic haemodialysis and of bicarbonate in dialysate: comparison of three techniques and their mathematically derived values.
abstract: The study deals with the comparison of acid-base parameters in blood of patients on chronic haemodialysis and of bicarbonate dialysate determined by Gas-Check AVL 945, equilibration technique (ET), and a titrimetric method. The results show that an acceptable agreement exists between AVL and ET with respect to measurements of pH, pCO2, HCO3-, and base excess. However, the values obtained for total buffer base related to the actual haemoglobin concentration are significantly lower (P less than 0.001) when determined by AVL. A titrimetric method is proposed for routine measurement of HCO3- in bicarbonate dialysate. Values obtained using this method are 3-4 mmol/l higher than those determined by AVL and ET. However, when the values for pK1' and for the solubility coefficient used in the Henderson-Hasselbalch equation are replaced by those for saline-bicarbonate solutions, results obtained using the titrimetric determined values agree well with those obtained by AVL and ET.
authors.affiliation: Klinik für Innere Medizin, Bereich Medizin (Charité) der Humboldt-Universität zu Berlin.
authors.forename: I
authors.initials: I
authors.lastname: Engelhardt
authors.forename: B
authors.initials: B
authors.lastname: Flemming
authors.forename: E
authors.initials: E
authors.lastname: Glatzel
authors.forename: K
authors.initials: K
authors.lastname: Precht
mesh_terms: D000085:Acetates / Q000378:metabolism; D000137:Acid-Base Imbalance / Q000097:blood*; D001639:Bicarbonates / Q000378:metabolism*; D001784:Blood Gas Analysis / Q000379:methods* / Q000592:standards; D015314:Dialysis Solutions / Q000378:metabolism*; D015312:Hemodialysis Solutions / Q000378:metabolism*; D006801:Humans; D012015:Reference Standards; D006435:Renal Dialysis; D014511:Uremia / Q000097:blood
chemical_list: D000085:Acetates; D001639:Bicarbonates; D015314:Dialysis Solutions; D015312:Hemodialysis Solutions