Albumin dialysis in critically ill patients: use versus omission of intradialytic heparin.

Albumin liver dialysis using the Molecular Adsorbent Recirculating System (MARS) (Teraklin AG, Rostock, Germany) is used in severe acute liver failure (ALF). We hypothesized that intradialytic heparin worsens preexisting hemostatic defects without enhancing system longevity or therapeutic efficacy. This was a retrospective, single center study of 10 critically ill patients (M : F = 8:2; mean age 58.5 +/- 16.5 years old; Acute Physiology and Chronic Health Evaluation II 25.0 +/- 3.5) treated with 31 MARS sessions (intradialytically heparinized : nonheparinized = 18:13). Mortality in this cohort was 80%. All MARS circuits were primed with dilute heparinized saline before commencement. However, intradialytic, intermittent, bolus heparin was administered on an ad hoc basis with circuit saline flush where indicated. Acute renal replacement therapy was instituted where indicated. Average total intradialytic heparin used was 757 +/- 389 IU. Circuit pressures were stable with or without intradialytic heparin. Significant reductions in serum urea, creatinine, ammonia, and total bilirubin were achieved using intradialytically heparinized and nonheparinized MARS. Thrombocytopenia and elevated activated partial thromboplastin time (aPTT) were further deranged post-MARS for both circuit types, but significantly so in intradialytically heparinized MARS: pre- versus post-MARS aPTT (s) 57.8 +/- 17.6 versus 88.7 +/- 48.0, P = 0.011, and platelet count (x 10(3)/L) 102.9 +/- 61.1 versus 84.4 +/- 50.5; P = 0.009. The use of low dose, intradialytic heparin during MARS exacerbates preexisting severe coagulopathy and thrombocytopenia in patients with severe ALF without enhancing circuit function and longevity. However, the role and safety of heparinized saline prime need further investigation.