Page 34 - Journal of Special Operations Medicine - Summer 2014

Table 4 SJT Data in Axillary Use
Time to Maximum Pressure
Hemorrhage Control ≥45 Seconds Under Device Rebleed After
Trial Cadaver (sec) Hemostasis? (mmHg) Release?
1 3 4 Yes 702 Yes
2 3 4 Yes 755 Yes
3 3 4 Yes 837 Yes
4 3 6 Yes 776 Yes
5 3 6 Yes 705 Yes
6 3 5 Yes 661 Yes
Average ± SD 5 ± 0.8 739 ± 62.9

Figure 3 Representative surface pressure tracing of SJT use may be ineffective since junctional hemorrhages are so
in the inguinal area measured via use of a compression sensor challenging early in care. Preparedness in the form of
placed between the skin and the pressure source. an available, effective junctional tourniquet with its cor-
responding training for possible users may save civilian
lives as well.

With the methods used, we observed variability in the
number of pumps of the bulb needed during TCD use.
This variability resulted from loosening the belt and repo-
sitioning the TCD between each trial such that the TCD’s
location changed a bit and affected how well it targeted
the artery. Furthermore, the variation in TCD position-
ing appeared to cause variation in how much pressure
Figure 4 Representative surface pressure tracings of SJT use was needed for hemorrhage control. Although these ob-
in the axillary area measured via use of a compression sensor servations were not hypothesis-driven, they make sense
placed between the skin and the pressure source. according to the understanding of mechanical hemor-
rhage control, and they may need further study.

The present experiment had several limitations. The
experiment was designed to provide sufficient evidence
for the regulatory clearance of the medical device and
not to simulate battlefield care. Cadaver tissue is not
live tissue. Cadavers have no coagulation and they may
have less collateral flow than normal humans. The ex-
periment was conducted under ideal circumstances such
that the results represent efficacy under those specific
Traditionally, the most lethal types of injury on the conditions; they do not necessarily reflect clinical effec-
battlefield are seldom encountered in the civilian set- tiveness. A controlled laboratory setting is not a chaotic
ting. Nonetheless, recent events have encouraged some battlefield environment. The short application times
adoption of military care techniques in the civilian sec- may not be indicative of those occurring with the nor-
tor. Improvisation may be effective in some cases for mal first-time users since the users were both trained
14
extremity hemorrhage, as demonstrated by the reported and experienced. Moreover, presented times of applica-
use of improvised tourniquets by emergency medical tion do not include the time taken to unwrap the device,
services responders and bystanders in the Boston Mara- place it around the patient, and secure it.
thon bombing. However, junctional hemorrhage is a
15
more complex injury and improvisation may be ineffec- Also, the user on the inguinal area was the developer
16
tive. Junctional wounds are more anatomically com- of the SJT and another person who helped in develop-
plex and larger, involve larger blood vessels that bleed ment of the SJT was the user on the axilla area; neither
faster and are in need of faster hemorrhage control, and of these users probably represents the average intended
are more often associated with other wounds that may user. Future directions for research include normal hu-
indicate other lifesaving interventions. Improvisation man subject testing, testing by medics on manikins and

24 Journal of Special Operations Medicine Volume 14, Edition 2/Summer 2014