Acute dialysis: PMN-elastase as a new parameter for controlling individual anticoagulation with low molecular weight heparin (Fragmin)

The effects of citrate dialysate in hemodialysis on polymorphonuclear elastase interaction with tissue factor and its inhibitor

BACKGROUND

This study aimed to investigate whether hemodialysis (HD) affects tissue factor (TF), tissue factor pathway inhibitor (TFPI), and polymorphonuclear elastase (PMNE) in endstage renal disease (ESRD) patients when eliminating the effects of heparin. Also, to explore the interaction of TF, TFPI, and PMNE throughout a single HD session.

METHODS

We enrolled 57 ESRD patients who had undergone hemodialysis for >3 months as an experimental group. Plasma levels of TF, TFPI and PMNE were measured by ELISA in 24 ERSD patients on intermittent HD using low-molecular-weight heparin (LMWH) as anticoagulation (LMWH group) and 33 ESRD patients using citrate as anticoagulation (citrate group) at the start and at 1, 2 and 5 h of the HD session. Meanwhile,28 ESRD patients not on dialysis were enrolled as a control group and fasting venous blood samples were taken in the morning.

RESULTS

Compared with the control group, the plasma TFPI levels of the LMWH group and the citrate group were significantly higher (P=0.000, P=0.002, respectively) under baseline conditions as well as the plasma PMNE levels (P=0.001, P=0.02, respectively), whereas TF showed no difference (P=0.186). During HD with citrate, plasma TFPI decreased slightly (P=0.012) and PMNE increased significantly (P=0.008) at 1 h. The plasma TFPI levels of the citrate group correlate with PMNE at 2 and 5 h (P=0.001, P=0.008, respectively).

CONCLUSIONS

ESRD patients on HD have significantly higher TFPI and PMNE levels compared to patients not on HD under baseline conditions, while TF levels were similar between the three groups. TFPI and PMNE are differently regulated, but the plasma levels correlated during HD in the citrate group. It might be possible that PMNE plays a role in anticoagulative activity through TFPI.

Preparation and characterization of a thrombin inhibitor grafted polyethersulfone blending membrane with improved antithrombotic property

A thrombin inhibitor grafted polyethersulfone membrane with improved antithrombotic property.

Anticoagulation with low-molecular-weight heparin (dalteparin) in plasmapheresis therapy: initial experience

BACKGROUND

In contrast to other extracorporeal treatments no established regime exists for anticoagulation with low-molecular-weight heparin (LMWH) in plasmapheresis therapy. A study was conducted to investigate whether LMWH (dalteparin-Na) is suitable as an effective anticoagulant in plasmapheresis therapy.

STUDY DESIGN AND METHODS

Eleven patients with autoimmune neurological diseases and the necessity for a plasmapheresis therapy were enrolled. A capillary membrane filter was used. A total of 2000 mL of human plasma was isovolumetrically exchanged per plasmapheresis cycle. The anticoagulation was accomplished with a single bolus of LMWH (dalteparin) of 80 to 90 IU per kg of body weight. The system was visually monitored. Anti-factor (F)Xa activity, thrombin-antithrombin III complex (TAT), and prothrombin fragment 1+2 (F 1+2) were determined at regular intervals. Samples were taken from the collected plasma pool to determine the loss of LMWH during the plasmapheresis procedure.

RESULTS

All plasmapheresis cycles with LMWH were successful without complications. Approximately 40 percent of the initially administered LMWH bolus was lost by the large porous filter during the plasmapheresis. The anti-FXa values were determined to be 0.5 IU per mL during the entire plasmapheresis. TAT values were elevated (TAT median, 14.3 microg/L). F 1+2 values measured before the filter cartridge remained within the normal range for the entire plasmapheresis cycle (<1.2 nmol/L) and were increasingly elevated after the filter.

CONCLUSION

Our initial experiences with LMWH for anticoagulation in plasmapheresis indicate that a body weight adjusted dose of LMWH (dalteparin) is suitable for anticoagulation in plasmapheresis therapy. No complications were observed. The data are encouraging. Further investigations will show if and how the present anticoagulation regime could be further optimized.

Application of argatroban, direct thrombin inhibitor, in heparin-intolerant patients requiring extracorporeal circulation

This study describes the present knowledge regarding the clinical application of argatroban, a direct competitive thrombin inhibitor for heparin-intolerant patients, including those with congenital and acquired antithrombin III deficiencies, those with heparin-induced thrombocytopenia, and those with high levels of polymorphonuclear granulocyte elastase. These patients are often associated with intracircuit clot formation with heparin anticoagulation during extracorporeal circulation. Therefore, argatroban may be chosen as one of the alternate anticoagulants. Because the anticoagulant effect of argatroban is reflected in the prolongation of activated thromboplastin time, monitoring is easy, similar to that for heparin. Because argatroban has a fast acting anticoagulant effect without any cofactors such as antithrombin III, this drug is a favorable anticoagulant for heparin-intolerant patients with antithrombin III deficiencies requiring extracorporeal circulation. In adverse reactions to heparin, heparin acts as an antigen after complexing with platelet factor 4, which leads to life-threatening heparin-induced thrombocytopenia. As argatroban prevents heparin-induced platelet aggregation, it is effective for use as a therapeutic anticoagulant. In other clinical applications, heparin decreases antithrombin activity and causes intracircuit clot formation during extracorporeal circulation when the polymorphonuclear granulocyte elastase level is very high. The antithrombin activity shows less decrease when argatroban is substituted for heparin. These findings indicate that argatroban is a useful alternative anticoagulant in these heparin-intolerant patients.

The approach to anticoagulation in patients treated with extracorporeal therapy in the intensive care unit

No wholly satisfactory drug or system has yet been devised for preventing thrombosis in extracorporeal blood circuits needed for renal replacement treatments. Heparin is still regarded by some as a standard approach, but advances in many areas of intensive care unit (ICU) medicine have created the potential for saving the lives of many patients in whom heparin anticoagulation is no longer appropriate. Several nonheparin methods are now readily performed, and the great risk of bleeding that is imposed by the use of heparin demands that citrate or other nonheparin methods be made available in the ICUs of all major medical centers that deal with trauma or major surgical procedures. Details of the practicalities, difficulties, and advantages are compared for low-dose heparin, regional heparin, low-molecular-weight heparin, no-anticoagulant systems, citrate, and other anticoagulants for both intermittent and continuous modalities. The clinical features and complications in individual patients that impact on the selection of the best method of management are reviewed.