Page 84 - JSOM Fall 2019

The Use of Tranexamic Acid in the Prehospital Setting

A Retrospective Study

Justus Boever, BS *; Marian S. Krasowski, MD, PhD ;
1
2
Matthew Brandt, MD ; Timothy Woods, MD 4
3

ABSTRACT
Background and Purpose: Tranexamic acid (TXA) is a com- TXA should be considered an intervention to prevent coagu-
petitive inhibitor of plasminogen and functions as an anti- lopathy. The use of TXA is heavily emphasized in the Special
fibrinolytic. Several studies have shown a survival benefit Operations medical community.
for a trauma patient if TXA is used early. We sought to de-
termine how many patients in the prehospital setting who In 2005, the primary purpose of the CRASH-2 trial was to
qualified for TXA actually received an initial 1g bolus during compare mortality rates of the patients who received TXA
the prehospital time period prior to arrival at a single level 1 with the rates of those who did not. This 5-year study spanned
trauma center. Methods: We conducted a retrospective analy- more than 40 countries and included more than 20,000 pa-
sis of trauma registry data at Cox South Level 1 Trauma Cen- tients. Trauma patients who appeared older than 16 years old
ter in Springfield, MO. Patient data collected included pulse, received TXA or placebo if they were found to have a pulse of
systolic blood pressure on admission, unassisted respiratory ≥110 beats per minute (bpm) and/or a respiration rate of ≥30
rate on admission, TXA administration, ambulance service, or ≤10 breaths per minute and/or a systolic blood pressure
elapsed scene time, transit time, and total time from ambu- (SBP) of ≤90mmHg. The entire TXA group, which included
lance arrival at scene to emergency department arrival. Re- more than 10,000 patients, had an absolute mortality reduc-
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sults: Among patients admitted to our trauma center at Cox tion by 1.5% if TXA was received within 3 hours of injury.
South, between October 1, 2015, and September 30, 2017, we The benefit of TXA is strongest if given within 1 hour from
found that 247 patients met the inclusion criteria for TXA ad- injury (5.3% vs 7.7% death by bleeding). This is consistent
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ministration. Of those, 5, or 2.02%, received the drug during with the findings of Gayet-Ageron et al., who found that for
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the prehospital period. Conclusion: Data showed that the rate every 15 minutes of treatment delay (excluding the first hour),
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of prehospital administration of TXA in the population ob- the benefit of TXA drops by 10%. Importantly, there was no
served is 2.02%, which highlights a lack of engagement within significant increased risk of pulmonary embolism (PE), deep
the civilian prehospital community with regard to TXA. Some vein thrombosis (DVT), myocardial infarction, or cerebrovas-
limitations of our study are that it is retrospective, the sample cular accident for those receiving TXA in the CRASH-2 study. 2
size is relatively small in comparison with the population sur-
rounding the receiving hospital, and some prehospital crews In 2012, Morrison et al. found that TXA use was associated
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may have slightly different qualifying criteria for TXA. with an unadjusted reduction in mortality rate among 896
combat casualties arriving at a single surgical site in Afghan-
Keywords: tranexamic acid; TXA; antifibrinolytic; prehospi- istan between 2009 and 2010. In that group, 293 received
tal; emergency medical services; EMS; trauma; advanced life TXA at the discretion of the managing clinician. For patients
support; ALS receiving 1 unit of blood, there was a 6.5% reduction in mor-
tality (17.4% vs 23.9%, respectively; p = .03). The benefit was
greatest in the group of patients who received more than 10
units of blood, with a survival odds ratio of 7.228 (95% con-
Introduction
fidence interval, 3.016–17.322). There was a higher rate of PE
TXA, originally approved by the US Food and Drug Admin- and DVT in the TXA group. However, it is unclear if this was
istration in 1986, inhibits fibrinolysis and has been shown to due to TXA administration as those patients tended to have a
1
improve outcome when used for the treatment of hemorrhagic higher ISS score.
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shock. It is a powerful antifibrinolytic that inhibits plasmin
breakdown of fribrin and saturates lysine-binding sites on Traumatic brain injury and subarachnoid and subdural hema-
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plasminogen, thus preventing the conversion of plasmino- tomas are contraindications for the administration of TXA.
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gen to plasmin. TXA has been shown in studies to reduce Other contraindications for TXA include thrombogenic car-
blood loss by one-third. In addition, Gayet-Ageron et al. diac rhythm disease, hypercoagulopathy, and a history of
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5,6
concluded that TXA administration can maintain stable fibrin thrombo embolism. 1,10 Thrombosis remains a concern for those
clot formation by protecting fibrinogen stores. They proposed administering TXA. However, the results of several studies
*Correspondence to justuscb@gmail.com
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1 Mr Boever was an EMT at CoxHealth Trauma Services and is currently enrolled in medical school. Dr Krasowski is the research coordinator
for Trauma Services at CoxHealth and completed his PhD in biomedicine in June 2019. Dr Brandt is the medical director of prehospital medicine
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at CoxHealth and the South West Regional Medical Director for Missouri. Dr Woods is medical director for CoxHealth Systems Trauma and
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Acute Care Surgery.
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