Aim: Evaluate the relationship between anti-Xa activity and anticoagulant effect, and ascertain whether accumulation of low-molecular-weight heparins (LMWH) occurs during haemodialysis.
Methods: There was an observational, single-centre study among participants who received the LMWH dalteparin, enoxaparin or nadroparin. A standard haemodialysis session lasted 4 hours. All included participants had anti-Xa activity measures at 0.5 and 4 hours. Extracorporeal circuit (ECC) clotting was evaluated by visual inspection of the haemodialyser and bubble trap after each haemodialysis session. The same person was tested at three consecutive haemodialysis sessions.
Results: Overall, 90 participants were enrolled and 259 haemodialysis sessions assessed. There was no significant difference in the mean anti-Xa activity at 0.5 and 4 hours for three consecutive sessions, so LMWH accumulation did not occur. There were 69 (26.6%) sessions in which, ECC clotting was visible. Compared with the group where circuit clotting did not occur, the LMWH dose and anti-Xa activity in the group where circuit clotting occurred were significantly lower. At 0.5 hour, anti-Xa <0.88 IU/mL had significantly higher odds of ECC clotting than that at ≥0.88 IU/mL. At 4 hours, anti-Xa <0.35 IU/mL had significantly higher odds of ECC clotting than that at ≥0.35 IU/mL.
Conclusion: We found that over three haemodialysis sessions, no significant accumulation of LMWH was evident in subjects receiving a LMWH dose of between 2000 and 5000 IU for regular. Anti-Xa activity measurement can be used to adjust the dosage of LMWH and predict the anticoagulant effect during haemodialysis.
Keywords: LMWH; anti-Xa; anticoagulation; haemodialysis.
© 2020 Asian Pacific Society of Nephrology.