Hemodialysis and heparin. Alternative methods of measuring heparin and of detecting activation of coagulation.
A bolus dose of heparin was administered pre-dialysis to patients (n = 6) undergoing regular maintenance hemodialysis with cuprophane flat plate and hollow fiber membranes. Blood samples were withdrawn at hourly internals for measurement of a) heparin and b) activation markers of coagulation, fibrinolysis and platelets. Two assay methods for heparin were employed; amidolytic assay of anti-factor Xa activity in plasma and a simple whole blood clotting time based upon factor Xa inhibition (Heptest). Results from these heparin assays correlated well with each other (r = 0.89) and both showed similar negative correlations (r = -0.72, amidolytic and r = -0.66, Heptest) with levels of a marker of fibrin clot formation, fibrinopeptide A (FPA). Large differences in levels of FPA were observed during dialysis with the two dialyzer types, when similar levels of heparin were present. Heparin levels declined from 1-5-h dialysis and were associated with rises in plasma levels of FPA, thrombin-antithrombin complex (TAT) and beta thromboglobulin (BTG), but not of D-dimer. Regression analysis revealed the best correlation was between FPA and TAT (r = 0.94), followed by FPA and BTG (r = 0.81). FPA and D-dimer exhibited significant, but lower (r = 0.42), correlation. TAT levels, like FPA levels, showed good correlation with heparin (r greater than 0.65). It is concluded that the Heptest assay may be a useful bedside measurement of heparin levels and the TAT assay may be a simplified means of evaluating coagulation system activation during dialysis.
Ireland
H A
HA
Department of Haematology, Charing Cross and Westminster Medical School, London, UK.
Boisclair
M D
MD
Lane
D A
DA
Thompson
E
E
Curtis
J R
JR
D000990:Antithrombin III / Q000032:analysis; D015415:Biomarkers / Q000097:blood; D015951:Factor Xa; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005342:Fibrinolysis / Q000187:drug effects*; D005344:Fibrinopeptide A / Q000032:analysis; D006493:Heparin / Q000097:blood*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy*; D010447:Peptide Hydrolases / Q000032:analysis; D010974:Platelet Aggregation / Q000187:drug effects*; D006435:Renal Dialysis / Q000295:instrumentation*; D014914:Whole Blood Coagulation Time; D001620:beta-Thromboglobulin / Q000032:analysis
D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C046193:antithrombin III-protease complex; D001620:beta-Thromboglobulin; C036309:fibrin fragment D; D005344:Fibrinopeptide A; D000990:Antithrombin III; D006493:Heparin; D010447:Peptide Hydrolases; D015951:Factor Xa