ANTICOAGULANT REGIMENS IN ACUTE CONTINUOUS HEMODIAFILTRATION - A COMPARATIVE-STUDY

Objective: To compare and contrast different heparin regimens for extr acorporeal circuit anticoagulation in patients receiving acute continu ous hemodiafiltration (ACHD). Design: Prospective controlled randomize d comparisons of the following regimens: 1) Low dose (500 IU/h) prefil ter heparin versus regional anticoagulation in patients on continuous arteriovenous hemodiafiltration (CAVHD) via A - V shunt. 2) Low dose p re-filter heparin versus no anticoagulation in patients receiving CAVH D via femoral cannulae. 3) Low dose pre-filter heparin versus regional anticoagulation in patients on continuous veno-venous hemodiafiltrati on (CVVHD). 4) An assessment of the consequences of the use of no anti coagulant in patients predicted to be at high risk of hemorrhagic comp lications on treatment with CVVHD. Setting: University Teaching Hospit al ICU. Patients: 64 ICU patients with acute renal failure. Measuremen ts and main results: Haemofilter survival during shunt CAVHD was signi ficantly prolonged by the use of regional anticoagulation compared to the use of low dose heparin (mean filter survival: 57.1 h versus 42.9 h; p < 0.05). In CAVHD using femoral cannulae, no significant differen ces in haemofilter survival were found between anticoagulation with lo w dose heparin and the use of no anticoagulant (mean filter survival: 55 h versus 52.5 h; NS). During CVVHD, regional anticoagulation compar ed to low dose heparin produced a trend towards prolonged filter life which was, however, not statistically significant (mean filter surviva l: 40.5 h versus 31.4 h; NS). In patients assessed to be at high risk of bleeding, CVVHD without anticoagulation provided a mean filter surv ival of 40.9 h (95 % CI 27 - 54.8 h). Conclusions: Regional anticoagul ation leads to longer filter survival than low dose heparin in shunt C AVHD. A regimen of no anticoagulation during femoral CAVHD leads to a filter life similar to that of low dose heparinization. During CVVHD, regional anticoagulation and low dose heparin are associated with simi lar filter survival times. In patients assessed to be at high risk of bleeding, treatment with CVVHD without anticoagulation results in adeq uate filter survival.