Page 67 - JSOM Spring 2018

reflecting contemporary standards of care. The TXA treatment wherein Armed Forces medics are faced with the challenges of
group had lower, unadjusted all-cause mortality (17.4% ver- mass casualty incidents (MCIs). The increase in MCIs has also
sus 23.9%) despite being more severely injured (injury severity been noted in civilian realms in the setting of international and
score, 25.2 versus 22.5). Patients who required massive trans- domestic terrorism, highlighted most recently with the Boston
fusion had a greater mortality benefit (14.4% versus 28.1%). Marathon bombing, where more than 264 were wounded; the
Although the MATTERS study was not a randomized con- Orlando Pulse Nightclub shooting, where 49 people were killed
trolled trial, it did address many of the shortcomings of the and another 53 wounded; the Paris terrorist attacks, where a
CRASH-2 trial, though one must be cautious generalizing its staggering 130 people were killed and another 368 wounded;
findings outside of the military combat setting. and the Las Vegas mass shooting, where 58 people were killed
and 546 people were wounded, demonstrating the scope and
Increasing scientific support for the early use of TXA as a phar- impact of mass casualty events, and the implicit challenges in
macologic adjunct in the management of hemorrhagic shock is delays to patient access, assessment, treatment, and egress. In
driving interest in its civilian prehospital use. Currently, there these settings, where medics are outnumbered by casualties,
are few studies of its use in this population. There are also lim- it is not uncommon for the medic to become task saturated,
ited data on IM or oral administration of TXA for hemorrhagic thus compromising how quickly and how many casualties can
shock. In tactical scenarios where operational realities affect be assessed, triaged, and critical interventions performed. Ad-
medical interventions, alternate routes of TXA administration vantages of IM TXA are that a skilled medic could administer
could provide significant tactical and trauma care advantages. multiple doses to multiple casualties in a shorter time without
having to establish IV or IO access, which, in turn, would en-
The rationale behind IM administrations reflects four key able the medic to assess more casualties, treat more casualties,
concepts: have more time to perform other lifesaving critical interven-
tions, and organize, prioritize, and execute tactical evacuation.
(1) Vascular access proficiency
Not all tactical medical care providers have paramedic or Methods
advanced medical training. Many SWAT and combat teams
operate with medics whose primary role is that of a SWAT To provide guidance on this subject, the following questions
Operator or combatant, and the medic role is secondary. As were asked sequentially to arrive at an evidence-guided, ra-
such, there is wide variability in prehospital care providers’ tionale-based recommendation on the use for, or against, IM
experience, dexterity, and proficiency in establishing IV or in- administration of TXA. All searches were performed by a
terosseous (IO) access in a timely fashion and under duress. medical librarian from the College of Physicians and Surgeons
Even in the hands of experienced emergency medical techni- of British Columbia over 2 months from January to February
cians and paramedics, studies have shown that, in general, 2015, using EMBASE and MEDLINE databases.
obtaining prehospital IV access is associated with longer EMS
on-scene times and longer prehospital times ; moreover, the 1. Is there evidence supporting the use of TXA in trauma
5
success rate of IV access declines with each subsequent at- patients?
tempt, with minimal improvement of overall success rate seen 2. Is there evidence supporting the prehospital use of TXA in
after second attempts. 6 trauma patients?
3. What is the risk (incidence) of venous thromboembolism
(2) TXA administration is time sensitive (VTE) or deep vein thrombosis (DVT) related to adminis-
Current resuscitative paradigms target stabilization of first tration of TXA?
clot with the early and aggressive use of balanced blood 4. What is the optimal timing of TXA administration in pa-
products and TXA as part of a damage control or hemostatic tients after traumatic injuries?
resuscitative approach. 7–12 Because of the ease of IM adminis- 5. What is the optimal TXA dose?
tration, this route provides the potential advantage of earlier 6. What is the bioavailability of IM TXA and other IM medica-
TXA administration (i.e., before the patient goes into shock), tions currently used in prehospital or combat settings (i.e., epi-
because IM administration can be done through the fabric of nephrine, glucagon, atropine, pralidoxime, and diazepam)?
a uniform and more quickly than establishing IV or IO access, 7. Is there a safe upper limit for volumes, with respect to IM
thus allowing for early clot stabilization through the inhibition drug administration?
of fibrinolysis and mitigation of the hyperfibrinolysis seen in
up to 25% of patients in hemorrhagic shock. 7,8
Results
(3) Situational awareness In total, 183 studies were reviewed for this analysis.
One axiom that is consistent across all tactical medical realms
is the acknowledgment that sound tactics trump good medi- Questions 1 and 2
cine or, as the euphemism goes, a medically appropriate inter- A total of 31 articles were obtained using the search strat-
vention at the wrong tactical time can be deadly. An immediate egy, including five randomized controlled trials (RCTs), three
derived benefit of IM versus IV administration of TXA (or systematic reviews and meta-analyses, two prospective cohort
any drug, for that matter) is minimizing hands-on (and heads- studies, two retrospective cohort studies, four retrospective
down) time, thus maintaining, if not increasing, rescuer situ- chart or case reviews, two studies using prognostic models,
ational awareness to dynamic changes and ongoing threats. one economical evaluation article, and 12 review articles.

(4) Mass casualty incidents One of the review articles was excluded. One article exam-
In consecutive years at the Special Operations Medical Asso- ined TXA administration in patients undergoing surgery for
ciation annual meeting, casualty vignettes have been presented maxillofacial injuries; the other looked at TXA administration

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