PLASMA HYPERCOAGULABILITY IN HEMODIALYSIS-PATIENTS - IMPACT OF DIALYSIS AND ANTICOAGULATION

Background. Thrombotic complications are common in patients with endst age renal disease and contribute substantially to the morbidity and mo rtality in this population. The aim of the present study was to: i) de termine the prevalence and the extent of hypercoagulability in patient s undergoing dialysis treatment by measuring. parameters that directly reflect thrombin concentrations; ii) assess changes in coagulation st atus during haemodialysis (HD); iii) quantify the relative impact of h eparin, dialysis and their combined effects on coagulation status and iv) detect factors that modify coagulation haemostasis in dialysis pat ients. Methods. A total of 39 patients (HD: n = 29, CAPD: n = 10) was analysed for procoagulatory and fibrinolytic activity determined by me asurements of partial thromboplastin time, prothrombin fragments F1+2, thrombin-antithrombin complexes and D-dimer concentrations. HD patien ts were investigated prior to and during dialysis. A subgroup of patie nts was infused heparin alone without dialysis or was dialysed without heparin administration. Furthermore, subgroup and correlation analyse s were performed for the type of dialysis (HD vs CAPD), dialyzer and s hunt, Kt/V, underlying disease and treatment with recombinant erythrop oietin (rhEPO). Results. Baseline levels of all parameters - procoagul atory and fibrinolytic - were substantially elevated in all patients, but to a higher degree among those on CAPD. Moreover, haemodialysis tr eatment increased procoagulatory markers even further, suggesting stim ulated coagulation and/or insufficent anticoagulation during dialysis. However, after 3 h of dialysis thrombin concentrations, determined by quantification of prothrombin fragments, were inversely correlated wi th Kt/V. Selective heparin infusion diminished procoagulatory activity only slightly and incompletely, whereas HD without heparin resulted i n excess thrombin accumulation. Finally, subgroup analyses revealed mo re pronounced thrombin formation among patients treated with polysulfo n dialyzers, whereas erythropoietin dosage was positively related with lower procoagulatory activity. Conclusion. A majority of patients on dialysis are in a hypercoagulable state, which is further aggravated b y the haemodialysis procedure itself and may not be sufficiently contr olled with current anticoagulation regimens. Intensified heparin treat ment and the use of rhEPO are likely to improve coagulation haemostasi s, whereas the type of dialyzer should be considered as a relevant pro coagulatory factor.