Page 39 - Journal of Special Operations Medicine - Fall 2015

complex than limb tourniquet use, because of collateral the setting of nonaortic pressure points is unclear, as it
arterial flow. Hence, during JT use, some arteries near, could mean that (1) collateral flow is present but there
but not directly under, the pressure point remain open is no loss of hemorrhage control (as in the SJT use case
and continue to allow the flow of blood around the pres- report); (2) collateral flow is present and there is loss of
sure point. Multiple arterial branches and anastomoses, hemorrhage control (hypothetically, this may be seen on
therefore, maintain a certain reduced perfusion of distal wound assessment); or (3) collateral flow is absent and
tissues. Such collateral flow may be pulsatile, but often there is loss of hemorrhage control (hypothetically, this
the quantity of flow is less than normal. The pulse may may be seen on wound assessment).
actually return to become detectable but diminished near
the pressure point (e.g., the common femoral artery area For aortic pressure points, absence of distal pulse return
where it is normally palpable in the femoral triangle of is expected unless hemorrhage control is lost (e.g., by
the groin). This aspect of collateral flow in the context device displacement in patient transfer). For casualties
of hemorrhage is not fully scientifically understood, but with multiple distal wounds, the return of collateral
in animals in the USAISR laboratory where we occa- flow may pose an undefined risk for loss of hemorrhage
sionally have opportunities to see it in wounds, the flow control of such distal wounds, distal extremity compart-
appears to be weakly pulsatile and less than normal as ment syndrome, and other as-yet-unknown complica-
it slowly fills wounds from a retrograde direction. Such tions. Clearly, clinicians on or near the battlefield may
collateral flow is usually easy to control with dressings, be able to describe cases with or without such phenom-
and such easy control contradicts the normal antero- ena and clarify whether these issues are seen. Since such
grade flow, which is often faster and more difficult to phenomena presently remain hypothetical, detection of
control without aggressive countermeasures like JTs. morbidity is important (albeit not as important as pres-
ervation of survival).
The return of the distal pulse is heralded by redetection
by manual palpation or Doppler ultrasound. The dura- Experiences in Training JT Users: 2011–2014
tion (time lag) between the periods of pulse detection In early 2011, the CRoC was the main model of JT dis-
appears to be brief; in studies of normal volunteers, the cussed in FAST medical team reports and related me-
lag appears to vary, but, so far, it seems to be between dia. However, subsequently, additional JT models were
10 and 45 seconds. 26,31,33 In one study, it appeared that cleared by the FDA. Since the JTs were so new, few
a minority of people may not have a return of the dis- Medics had heard of them, were familiar with them, and
tal pulse during pressure point compression, or at least had trained with them. In the subset of experienced pre-
the lag time was indeterminate during the time period hospital medical personnel who had already cared for
for which it was observed. Furthermore, since all data at least one casualty with junctional hemorrhage, many
33
are from normal volunteers, none are available from pa- understood the need. Most of those trained in SJT and
tients, let alone those at risk for shock. In another study JETT use were already trained on the SAM Pelvic Sling
of successful use of JTs on normal volunteers, the rates II (SAM Medical Products; www.sammedical.com), a
of collateral flow were high and rates appeared to vary medical device already in US Army medical sets, kits,
by pressure point. The abdominal aortic pressure point and outfits. The SAM Pelvic Sling II was the basis upon
31
appeared to have no effective collateral artery, so the which the SJT was made, so the familiarity of the pelvic
lag appears to be long or indefinite. A separate study sling aided in the training of the SJT. Medics who were
31
showed that SJT use on normal volunteers stopped the trained preferred the SJT.
pulse and reduced intramuscular pulse pressure distally,
but thigh and calf skeletal muscle perfusion was main- The USAMEDDC&S Combat Casualty Care Course
tained at 25% to 35% of normal baseline levels. Such (C4), a week-long block of instruction for military med-
26
results suggest that JTs may be used to control hemor- ical officers (e.g., medical students, residents, physician
rhage yet allow residual tissue perfusion even when pulse assistants), has provided some training on JTs for years.
pressure is absent. A case originally reported within The training has been for familiarization and has not fo-
26
the Joint Trauma System of an SJT used for inguinal cused on student use of JTs. At Camp Bullis, Texas, the
bleeding had the distal pulse return without loss of hem- C4 instructors train providers (physicians, nurses, den-
orrhage control, but this case had only a single gunshot tists, physician assistants, medical students, residents,
wound that was also packed. Therefore, the meaning interns, other medical officers) on all four JTs both in
25
of pulse stoppage in the context of JT use appears to the classroom and on outdoor combat training lanes,
be time dependent: pulse cessation and associated hem- and the experience has been very good. Given the risk
orrhage control occur during the first 15 seconds, but for pelvic injuries with associated extremity amputation
subsequent pulse return for nonaortic pressure points injuries, C4 participants carry the SJT to use as either
may be associated with resumption of collateral blood a pelvic binder, a JT, or as both. The dual indication is
flow. Moreover, the meaning of hemorrhage control in valued especially if carrying space is limited.

Junctional Tourniquet Training Experience 27