ارزیابی چهار حالت ضد انعقادی خون با دوز پایین در طول همودیالیز مداوم An evaluation of four modes of low-dose anticoagulation during intermittent haemodialysis

Background Standard intermittent haemodialysis (SHD) includes anticoagulation with unfractionated heparin (heparin) or low molecular weight heparin (LMWH) to avoid clotting of the extracorporeal circuit of the dialysis system [1]. In patients at risk of bleeding, while needing haemodialysis, one option is to use intravenous regional citrate infusion. This technique is so far only commercially available for continuous veno-venous haemodialysis (CVVHD) used in intensive care units and needs narrow clinical and laboratory surveillance. Except for a few centres with developed methods of narrow surveillance [4, 6, 10, 11], regional citrate anticoagulation (RCA) therefore is considered unsuitable for intermittent haemodialysis due to the need of extensive surveillance, to avoid risk of hypo- or hypercalcaemia. In untrained hands, RCA has been recommended to be limited to intensive care [8]. Therefore, other options may be considered for intermittent haemodialysis in patients at risk of bleeding. Another way to restrict anticoagulation during intermittent haemodialysisis is by using saline flushes, heparin-coated dialyzers [2–9], dialysis fluid containing citrate[12, 13]or by combining heparin-coated dialyzers with citrate dialysate [14]. However, these methods may end up in frequent clotting (50% interrupted treatments) [15]. A pharmacological heparin coating of the dialyzer and the extracorporeal circuit, without using any heparin at the start, is another option. Such method is the manual priming by perfusion of the extracorporeal circuit with a combination of heparin and albumin that is discarded before intermittent haemodialysis [16, 17]. A prior in vitro study indicated that priming the extracorporeal circuit with only either saline or an albumin solution caused a greater risk for clotting in comparison to priming with heparin in saline or heparin and albumin in saline [18]. Saline flushes can cause fluid retention while regional citrate anticoagulation needs careful surveillance especially of ionized Ca2+ [12, 19]. A clotting of the extracorporeal circuit causes interrupted haemodialysis but also a blood loss up to 300 ml. Still, there is no golden standard for anticoagulation during intermittent haemodialysis in participants at bleeding risk [8]. The aim of this study was to clarify to what extent four different low-dose anticoagulant modes, versus standard haemodialysis, could reduce the administration of heparin while enabling dialysis.