It is anticipated that tinzaparin used at a fixed dose for thromboprophylaxis in severe CKD patients (eGFR ≤ 30 ml/min /1.73 m2) at risk for venous thromboembolism (VTE) will not bioaccumulate at a significant level, meaning an increase of ≥ 20% of the anti-Xa mean level between day 2 or 3 and day 5.