Efficacy of enoxaparin in preventing coagulation during high-flux haemodialysis, expanded haemodialysis and haemodiafiltration

Abstract

Background Low-molecular-weight heparins (LMWHs) are easily dialysable with high-flow membranes; however, it is not clear whether the LMWH dose should be adjusted according to the membrane type and dialysis technique. This study aimed to evaluate the influence of the dialyser on anticoagulation of the extracorporeal dialysis circuit. Methods Thirteen patients received the same dose of LMWH through the arterial port via three dialysis techniques: high-flux haemodialysis (HF-HD), online haemodiafiltration (HDF) and expanded haemodialysis (HDx). All dialysis was performed under similar conditions: duration, 4 h; blood flow, 400 mL/min; and dialysate flow, 500 mL/min. Antifactor Xa (aXa) activity and activated partial thromboplastin time (APTT) were measured before and after the dialysis. Clotting time of the vascular access site after haemodialysis, visual clotting score of the dialyser and any complications with the extracorporeal circuit or bleeding were registered. Results Post-dialysis aXa activity in HF-HD (0.26 ± 0.02 U/mL) was significantly different from that in HDF (0.21 ± 0.02 U/mL, P = 0.024), and there was a trend in HDx (0.22 ± 0.01 U/mL, P = 0.05). APTT post-dialysis in HF-HD (30.5 ± 0.7 s) was significantly different from that in HDx (28.2 ± 0.64 s, P = 0.009) and HDF (28.8 ± 0.73 s, P = 0.009). Conclusions AXa activity in HDF was significantly lower than that in HF-HD, possibly because of more losses of LMWH through the dialyser. Given the higher anticoagulant loss in HDF and probably in HDx than in HF-HD, the enoxaparin dose administered may be adjusted according to the dialysis technique.

Expanded hemodialysis: Is anticoagulation of the dialysis circuit different from online hemodiafiltration and high‐flux hemodialysis?

“…The delay in LMWH reaching the dialyzer when applied through venous port, with decrease in enoxaparin blood concentration, leads to its anticoagulation effect before reaching the membrane and to a less‐efficient enoxaparin removal than that through the arterial port. In fact, when enoxaparin was administered through the arterial line in similar circumstances, significant differences were found in postdialysis aXa [26], supporting our hypothesis. Earlier study found differences in aXa comparing two different dialyzers in HDF, with enoxaparin applied through the venous port [20].…”

Comparison of the injection of low‐molecular weight heparin in the arterial vs. venous blood line for preventing extracorporeal circuit clotting during hemodialysis

“…This may result from higher LMWH removal, although it has been hypothesized that a high ultrafiltration volume applied during OL‐HDF may increase procoagulatory activity via shear stress and decrease of aXa activity levels through enoxaparin consumption 22 . In MCO‐HD, a trend towards lower post‐dialysis aXa levels compared to HF‐HD has also been reported when enoxaparin 40 mg was administered through the arterial blood line 5 min after the start of dialysis 20 . Besides removal or consumption of LMWH, other mechanisms may be involved in the decrease of aXa activity after dialysis sessions.…”

“…22 In MCO-HD, a trend towards lower post-dialysis aXa levels compared to HF-HD has also been reported when enoxaparin 40 mg was administered through the arterial blood line 5 min after the start of dialysis. 20 Besides removal or consumption of LMWH, other mechanisms may be involved in the decrease of aXa activity after dialysis sessions. Indeed, since LMWH are negatively charged, adsorption-binding and clearance rate may vary, depending on the surface roughness and electrical charge of dialysis membranes.…”

Optimising the Nadroparin Dose for Thromboprophylaxis During Hemodialysis by Developing a Population Pharmacodynamic Model Using Anti-Xa Levels

“…Moreover, HDF as compared to HD removes larger molecules to a greater extent due to use of convection as compared to diffusion, which may also explain the difference in nadroparin clearance between these types of hemodialysis [6,30,31]. Some studies reported a significantly lower anti-Xa level in HDF versus high-flux hemodialysis (HF-HD), indicating a higher nadroparin clearance in HDF versus HF-HD [32,33]. However, Sridharan et al reported no difference in required LMWH dose to achieve adequate anti-Xa levels between HDF and HF-HD, suggesting no effect of dialysis mode on nadroparin clearance [34].…”