Low molecular weight (LMW) heparin has been compared to standard unfractionated (UF) heparin in hemodialysis/hemofiltration in a 12 month, randomized study. Seventy patients with end-stage chronic renal failure starting dialysis treatment were randomly assigned to one of two groups treated with either LMW or UF heparin. The LMW and UF heparin doses used produced similar plasma anti-FXa levels, and comparable antithrombotic effectiveness was observed in the two groups as reflected in similar incidences of thrombus formation in the extracorporeal circulation: 1.59% and 1.33% for LMW and UF heparin, respectively. No bleeding complications were seen with either heparin, but significantly (P less than 0.05) fewer erythrocyte concentrates were needed in the LMW heparin patients. Mean factor VIII activities had risen significantly (P less than 0.001) after 12 months in the UF heparin group, whereas they were unchanged in the LMW heparin group. A significant (P less than 0.05) increase in plasma triglycerides was observed in the UF heparin group which was attributable to six (18.8%) of the patients in this group. Triglyceride concentrations remained relatively constant in the LMW heparin group. Post-heparin lipolytic activity, and in particular hepatic lipase activity, was not stimulated to the same extent in the LMW heparin-treated patients as compared to the UF heparin group. We conclude that LMW heparin is a suitable alternative to standard UF heparin for anticoagulation in hemodialysis/hemofiltration therapy. It may offer potential advantages with regard to a lower requirement for erythrocyte concentrates and less derangement of certain metabolic parameters, such as factor VIII, triglycerides and plasma lipase activity.

No abstract

No abstract

Blood coagulation studies were performed on 60 Hanover domestic pigs ready for slaughter and a total of 84 Goettingen minipigs. A tendency to hypercoagulability was found in these pigs, expressed in a shortened PTT, r- and k-time in the thromboelastogram and a slightly reduced plasminogen and plasmin level. Many values were similar to those of man. Thrombin time was longer. This may be due more to enhanced formation of fibrin degradation products (anti-thrombin VI) than to greater amounts of endogenous heparin being released. The longer reptilase and thrombin coagulase times support this. The thrombocyte count differed only slightly. The findings suggest that the Goettingen minipigs and Hanover domestic pig are suitable animals for comparative blood coagulation studies.

Low molecular weight (LMW)-heparin was used as the sole anticoagulant during hemodialysis and hemofiltration in a pilot study on 32 patients. A LMW-heparin dose corresponding to 50% of the patients usual unfractionated, standard (UF)-heparin dose was found to produce comparable plasma heparin levels (anti-FXa-activity). No thrombosis of the extracorporal system and no bleeding complications occurred at this LMW-heparin dose. In contrast to UF-heparin, LMW-heparin produced only slight increases in PTT and thrombin time in all patients. Lipoprotein lipase was stimulated only marginally by LMW-heparin, with a correspondingly reduced release of free fatty acids. Both heparin species caused similar elevations in factor VIII and fibrin monomers, thus excluding a difference in coagulation activation. On the basis of these results, long-term studies have been started at four nephrology centers. To date, 26 patients have been treated with LMW-heparin for 6 months. A LMW-heparin dose was used that produced plasma anti-FXa-activity of 0.5 to 0.9 U/ml (initial dose: 30 to 40; dose/hr: 8 to 15 anti-FXa-units/kg body wt). PTT and thrombin time were only increased by 5 sec on average. Surprisingly, the elevated pre-dialysis levels of factor VIII and fibrin monomers decreased during this 6-month period. Bleeding complications did not occur and thrombotic complications were not observed when the anti-FXa levels were above 0.5 U/ml. LMW-heparin, therefore, appears to be a good alternative to UF-heparin for dialysis patients and may present less risk of bleeding because of its reduced effect on PTT, thrombin time, and thrombocytes.