Tranexamic acid and international ambulance services

Haemorrhagic shock is a leading cause of death internationally, whether from serious trauma (Grassin-Delyle et al, 2018; Neeki et al, 2018) or other conditions such as postpartum haemorrhage (Shakur et al, 2010; Cannon, 2018). Severe haemorrhage can compromise the body's ability to form and maintain clots. This is because haemorrhage, hypoperfusion and haemorrhagic shock may result in dysregulation of coagulation systems, through pathologic release of fibrinolytic enzymes. These fibrinolytic enzymes have the effect of prematurely breaking down clots within the haemorrhaging patient, thereby compromising haemodynamic stability through excessive thrombolysis (Huebner et al, 2017; Grassin-Delyle et al, 2018; Neeki et al, 2018).

Tranexamic acid (TXA) inhibits the premature breakdown of blood clots, which may occur following severe haemorrhage. TXA is a synthetic derivative of lysine that inhibits the fibrinolysis of blood clots (Roberts, 2015; Jawa et al, 2016; MIMS, 2019). TXA appears to be a promising drug that—if administered early, such as during the prehospital phase of care—may reduce mortality from severe haemorrhage (Stansfield et al, 2020). In the United Kingdom (UK), TXA was first introduced to the South Western Ambulance Service Trust in December, 2011 (Paudyal et al, 2017) and has since become widely used by paramedics across the UK when treating patients with severe internal or external haemorrhage, postpartum haemorrhage and head injury (Association of Ambulance Chief Executives, 2019). However, other studies suggest that further research is required to demonstrate the efficacy of prehospital TXA administration (Napolitano, 2017), and it is perhaps for this reason that TXA is not yet widely used across all international ambulance services. For example, TXA administration across Australian ambulance services is largely restricted to the PATCH (2019) research study, while paramedic use of this drug in New Zealand has only recently commenced (St John New Zealand, 2019).