The Use of Tranexamic Acid (TXA) for the Management of Hemorrhage in Trauma Patients in the Prehospital Environment: Literature Review and Descriptive Analysis of Principal Themes.

Tranexamic acid (TXA) is an antifibrinolytic agent used to prevent traumatic exsanguination. It was first introduced to clinical practice for the management of patients with bleeding disorders, especially adapted to reduce bleeding in hemophiliacs undergoing oral surgical interventions. TXA exerts its action on the coagulation process by competitively inhibiting plasminogen activation, thereby reducing conversion of plasminogen into plasmin. This ultimately prevents fibrinolysis and reduces hemorrhage. Thus, TXA may be well suited for the management of traumatic hemorrhage in the prehospital setting.Despite multiplicity of studies on the use of TXA in clinical practice, there is no consensus regarding the use of TXA for the management of hemorrhage in trauma patients in the prehospital environment. Thus, a review on this topic was warranted. An extensive literature search yielded 14 full journal articles which met the inclusion criteria. These articles were thoroughly analyzed and the following themes were identified: "dose of TXA administration," "route of TXA administration," "optimal window of TXA administration," "safety of TXA use," "clinical effectiveness of TXA application," and the "feasibility of TXA use in the prehospital setting."Overall, to achieve the best possible outcomes, the literature supports the use of a loading dose of 1 g of TXA, followed by 1 g infusion over 8 h, given by intravenous administration within a 3-h window period of traumatic injury. TXA is very effective and safe to use in the prehospital setting, and its use is clinically and economically feasible.

Type I collagen degradation during tissue repair: comparison of mechanisms following fracture and acute coronary syndromes.

There is turnover of type I collagen during tissue repair. The degradation of type I collagen by matrix metalloproteinases (MMPs) is reflected by serum ICTP and that by cathepsins by CTX-I. There is evidence for increases in ICTP after acute coronary syndromes (ACS) and in CTX-I during fracture repair. The involvement of the MMP pathway in fracture repair and cathepsins after myocardial infarction is unclear. We studied 74 men; 22 were admitted to the hospital on the day of their ACS (ST or non-ST elevation myocardial infarction) (mean age 56 years, range 39 to 82) and 9 attended hospital on the day of their tibial shaft fracture (mean age 33 years, range 21 to 79); we had 43 age-matched controls (mean age 54 years, range 20 to 82). Subjects with ACS and tibial shaft fracture were followed up for up to one year; control subjects were used to establish a reference interval. We measured serum ICTP by ELISA (reference interval 1.1 to 17.6 ng/mL) and CTX-I by chemiluminescence (reference interval 0.094 to 0.991 ng/mL). After ACS, the mean ICTP increased from 5.41 to 6.60 ng/mL within one day of admission (p<0.05); the mean CTX-I increased from 0.263 to 0.414 ng/mL (p<0.05). In two cases, the CTX increased to above the reference interval. After tibial shaft fracture, the mean ICTP increased from 5.51 to maximum of 8.71 ng/mL within 28 days of admission (p<0.01); the mean CTX increased from 0.200 to 0.374 ng/mL (p<0.001). In four cases, the CTX increased to above the reference interval. We conclude that the MMP and cathepsin pathways are both implicated in tissue repair in the bone and heart. This may have clinical implications; drugs that block either pathway (TIMPs, cathepsin K inhibitors) may affect the repair of both tissues.