10.1 Heparin

Systemic heparin (unfractionated or LMW) is used routinely to prevent clotting of blood in vivo during haemodialysis.¹³⁹

Local low-dose heparin is used routinely to prevent clotting of peripheral venous or arterial catheters. A meta-analysis of randomised trials found that intermittent heparin flushes had no benefit over normal saline flushes. Heparin infusion prolonged patency of arterial catheters, but further studies are required to establish its benefit for venous catheters.¹⁴⁰ Evidence level Ia

10.2 Warfarin

Low-dose warfarin has been shown in two studies to be effective in prophylaxis of thrombosis in central venous catheters,¹⁴¹ and in prophylaxis of thrombosis during chemotherapy in stage IV breast cancer¹⁴² (see Table 3). Evidence level Ib

Minidose warfarin (1 mg/day, no INR monitoring) is recommended for prophylaxis of thrombosis in central venous catheters.

Low-dose warfarin (target INR 1.6, range 1.3-1.9) is recommended for prophylaxis of thrombosis during chemotherapy in stage IV breast cancer.