This study was designed to assess the principal markers of thrombogenicity and biocompatibility during
continuous veno-venous hemodiafiltration (
CVVHDF) using regional
citrate anticoagulation (RCA). In a prospective study, 11 procedures with a
polysulfone membrane were performed in nine
critically ill patients with
acute renal failure and impaired hemostasis. Blood samples were taken before and during
CVVHDF at diafilter outlet--before
calcium-induced reversal of the effect of
citrate--at 15, 60, 360, and 1440 minutes. In four patients, 10
CVVHDF sessions were performed with systemic
heparin anticoagulation (HA) using a
polyacrylonitrile membrane. During RCA, blood thrombocyte count, plasma
thrombin-
antithrombin III complexes,
beta-thromboglobulin, and
von Willebrand factor levels did not differ significantly from baseline. Plasma
D dimer levels rose significantly at 360 minutes; however, the difference between diafilter inlet and outlet levels was nonsignificant. There was a significant increase in plasma C5a concentrations and a decline in blood leukocyte count in the early phase of
CVVHDF. Just as in RCA, no increase in plasma thrombogenicity indices was observed during HA. However, clotting times in blood entering patients' circulation were significantly prolonged. Plasma C5a concentrations increased significantly at the beginning of
CVVHDF. RCA can effectively inhibit the thrombogenic effect of the extracorporeal circuit in
CVVHDF. The effect of HA may be similar, however, at the expense of systemic anticoagulation and risk of
bleeding. RCA, performed in a way that overcomes thrombogenicity, does not completely eliminate complement activation and/or transient
leukopenia during
CVVHDF.