FC 097INTERMITTENT HEMODIALYSIS WITHOUT ANTICOAGULATION
Authors: Frimmel Silvius , Hinz Michael , Mitzner Steffen , Koball Sebastian 
Published: May 2021

Abstract

Background and Aims
Dialysis therapy of patients at increased risk of bleeding is a well-known clinical problem. Systemic anticoagulation with heparin increases the risk of severe hemorrhage. Alternative strategies include the use of heparin-coated dialysis membranes, regional citrate anticoagulation, airless dialysis tubing, flushing the dialyzer with saline and earlier regional heparin anticoagulation with protamine reversal. However, either special devices (e.g. airless or heparin coated tubing) are needed, or the procedures are complex and require additional time and personnel resources for administration and monitoring. Current data on heparin-free dialysis are rare. After a pilot study from 282 dialysis sessions we reviewed 949 dialysis protocols from 2.5 years of 480 hospitalized and outpatient dialysis patients who were treated without systemic anticoagulation due to an increased risk of bleeding or a manifest hemorrhage. The duration of each dialysis session and the number of dialyses with or without clotting were evaluated.

Method
A total of 949 dialysis sessions of 480 patients were reviewed from October 2017 to January 2021. Dialysis were performed with Fresenius 4008/5008 (FX80,FX50, KF-210) and Gambro Artis (Poly170H, Theranova). All dialysis sessions were performed via AV-fistula with double-needle puncture or via single- or double-lumen central venous catheters (CVC). No additional technical devices or procedures were used beside standard hemodialysis or hemodiafiltration. Some of the patients had coagulopathies (sepsis, liver cirrhosis), thrombocytopenia or were on systemic anticoagulant therapy (vitamin K antagonists, DOAKs, heparin independent from dialysis therapy). The primary outcome was the need to interrupt the dialysis session because of clotting events due to a complete coagulation of the circuit, a partial coagulation of the circuit or a significant rise in the venous pressure.

Results
In 81 procedures (8.5%) systemic clotting made a discontinuation of the dialysis session necessary. In only 10 sessions (1%), the dialysis treatment had to be continued with new tubing and filter. More than one change of a system was never necessary. In the other 71 sessions, dialysis had to be stopped with retransfusion 5 minutes until 1.5 hours before the scheduled end of therapy, and therapy was considered as clinically sufficient. The frequency of clotting did not correlate with dialysis time (Fig.1.). Regarding the venous access clotting happened in 14.6% of acute CVC, in 12.6% of tunneled CVCs and in 9.4 % of AV-fistulas or -grafts, (Fig 2).

Conclusion
Dialysis without anticoagulation can be performed routinely with modern synthetic filters and dialysis concentrates. Patients at high risk of bleeding, with manifest hemorrhage or before surgery can undergo dialysis treatment for up to five hours without complications. In the present study clotting did not correlate with dialysis time. Patient-specific factors, as the venous access seem to play a more important role. In summary additional cost intensive devices, personnel intensive procedures and complex treatment protocols are only rarely needed to perform heparin-free dialysis for patients at risk.