Single-Bolus Tinzaparin Anticoagulation in Extended Hemodialysis Session: A Feasibility Study

KEY POINTS: A single bolus of tinzaparin is effective for 8-hour hemodialysis session. Eight-hour simulation sessions with anti-Xa monitoring are useful to adjust tinzaparin dose. BACKGROUND: Few studies have assessed the use of low-molecular weight heparins for anticoagulation during extended hemodialysis (HD) sessions. This study aimed to evaluate the efficacy of a single bolus of tinzaparin for anticoagulation of the extracorporeal circuit and dialyzer in 8-hour HD sessions. METHODS: This single-center study included all patients who underwent a single 8-hour simulation session as part of their nocturnal home HD training between 2009 and 2020. Tinzaparin was delivered as a single-bolus injection at time 0 with dosing on the basis of doubling of standard 4-hour session dose. Tinzaparin efficacy was examined using visual observations (score 1–4) of the dialyzer and venous bubble trap at the end of dialysis and using anti-Xa measured at 15 and 30 minutes and 1, 2, 4, 6, and 8 hours after HD start. RESULTS: Forty-seven patients were included. The mean tinzaparin dose was 107±20 IU/kg. Anti-Xa levels peaked at 15 minutes with 1.3±0.4 IU/ml and progressively declined reaching 0.9±0.3 IU/ml at 1 hour, 0.4±0.21 IU/ml at 4 hours, and 0.15±0.15 IU/ml at 8 hours. After the 8-hour session, none of the patients had severe clotting of their dialyzer or venous chamber. Moderate blood clotting was observed in the dialyzer of 6 patients (20%) and in the venous chamber of 22 patients (61%). On the basis of the simulation results, tinzaparin dose was increased in 27 patients (58%) with a mean home-discharge dose of 123±28 IU/kg. CONCLUSIONS: This study shows that anti-Xa levels stabilized rapidly after administration of tinzaparin for 8-hour HD. Administration of a single-bolus tinzaparin at the start of an 8-hour dialysis session seemed effective, although dose adjustment may be required.