Anticoagulants can prevent thrombi from forming in the deep veins of the leg.  The deep veins (DVTs) can break off and travel to the lungs, resulting in a pulmonary embolism (PE) – the most clinically important consequence of DVT.  However anticoagulants can lead to serious complications such as intracerebral hemorrhaging.

The consortium for spinal cord medicine published clinical practice guidelines for the prevention of thromboembolism in SCI (1999).  They recommended 5,000 units of unfractionated heparin for motor-incomplete patients for 8 weeks and either heparin adjusted to high normal activated partial thromboplastin time or low molecular weight heparin for motor-complete patients for 8-12 weeks.  Chiou-Tan et al. (2003) note that this recommendation is based on studies that showed that the risk of thromboembolism in SCI increases rapidly after injury and is maximal between days 7 and 10 (Green et al. 1982; Merli et al. 1988; Geerts et al. 1994).