Page 40 - Journal of Special Operations Medicine - Fall 2017

over time once the steady pressures were achieved, as deter- believe quantifying the actual intrapelvic pressure change bore
mined by the manometric system. This suggests that the ob- a closer relation to tamponade as the mechanism of action and
served steady pressure changes were not transient. we encourage use of this metric.

With respect to the preparation of each cadaveric model, in
Discussion
generating the simulated pelvic injuries described as AO/OTA
The UK national guidelines recommend the prehospital use 61-C1, we used a surgical approach to ensure standardization
of pelvic binders in managing patients with major trauma if between specimens. A previous study used an external rota-
there is any suspicion of a pelvic fracture given the mecha- tion force to both iliac wings to create an open-book pelvic
nism of injury, symptoms, or clinical findings. 4,17 The Commit- fracture. It is possible that this approach would create differ-
22
tee on Tactical Combat Casualty care recently incorporated ent injury patterns in different cadavers when categorized by
pelvic-binder application into the hemorrhage component of the AO/OTA systematic approach and, therefore, may impact
the MARCH algorithm (i.e., massive hemorrhage, airway, re- the ability to compare results between specimens in a model
spiratory, circulation, head or spinal or other injury). The ap- and between studies.
plication of a pelvic binder likely acts to prevent hemorrhage
via several mechanisms in an unstable pelvic fracture. First, Removing the trouser legs from a patient should not signifi-
the stabilization or splinting of newly fractured bone ends pre- cantly risk hypothermia. Appropriate prehospital management
vents further laceration of soft tissue and vasculature. Second, of a trauma patient includes the mitigation of hypothermia
this reduction in movement promotes stable clot formation. using products such as the hypothermia management and pre-
6
Third, decreasing the intrapelvic volume increases intrapel- vention kit, blankets or other appropriate items. Simple PCS
vic pressure and tamponades venous bleeding. Biomechanical should not be the only item standing between a trauma patient

studies have shown pelvic binders to be effective in reducing and hypothermia.
the symphyseal diastasis 15,16,18 and pelvic width, both of which
6
should theoretically increase intrapelvic pressure by reduction Despite the benefits of pelvic binder application in the pre-
in volume of the intrapelvic space. hospital setting, 15,20,21 there are important considerations to
their use in combat settings. For example, military forces are
Both the commercially available pelvic binder and those im- increasingly operating in small groups in austere, remote, and
provised using combat trousers significantly increased intra- hostile environments. Therefore, they are limited in the vol-
pelvic pressures from the baseline. The latter method is simple, ume and weight of equipment that can reasonably be taken
inexpensive, and uses equipment available to all British sol- into such environments. Although, ideally, all groups would
diers in any environment and combat situation. Very similar have access to a pelvic binder, this is not always practicable
trousers are used by militaries across the globe. These findings given the dimensions of current devices and the volume of
are particularly important clinically because the pressures ob- equipment required for operational effectiveness.
tained were considerably greater than normal central venous
pressures (8cmH O). This suggests these interventions could Another unique challenge in this context is time from point
14
2
be of use in tamponading venous bleeding from unstable pel- of wounding to extrication. An increasingly common problem
vic fractures, which is essential in the prehospital management is the requirement of prolonged field care. This can mean a
of pelvic injury. 4,19 patient being held in an austere environment due to remote
location or combat activity far longer than ideal medical man-
The cadaveric model used here was adapted from a pilot agement would dictate. Pelvic stabilization in this context is
study that was refined and developed in a larger study that vital to reduce hemorrhage; however, the specific equipment
11
used a balloon manometer to assess the change in intrapelvic to do so may not always be available.
pressure before and after an intervention. Results from this
12
study confirmed the methodology in allowing reliable moni- Military frontline units are becoming ever more flexible to
toring and measuring of intrapelvic pressure changes after adapt to these operational requirements. It is not always pos-
interventions. Change in intrapelvic pressure is likely directly sible to have specific equipment, due to logistical restrictions.
proportional to the mechanism of action of intrapelvic tam- Flexible and adaptable items are essential to meet this chal-
ponade. The results from this study also echo the results from lenge. With this theme, we propose that British military PCS
the previous study where pelvic binder and legs bound over a trousers can be adapted rapidly and used as an improvised
bolster increased intrapelvic pressure significantly compared pelvic binder, thus providing a possible method of stabilizing
with the baseline pressure and that the pressure achieved using pelvic fractures in the absence of specialized equipment. Every
both binding methods was not statistically different from the member of the British Armed Forces in an operational the-
pressure achieved with the TPOD binder. 12 atre wears this item and militaries worldwide use very similar
versions.
Our study differs from those previously published in that
we used the intrapelvic pressure as the end point. Several Limitations of our study include the small sample size of six
other studies have quantified the reduction in the symphy- cadavers. Despite this, our study has demonstrated clear trends
seal diastasis. 15,20,21 The Nunn et al. cadaveric study also in both interventions significantly increasing intrapelvic pres-
21
measured intraperitoneal pressure changes after application sure. A further possible confounder of the study is that it was
of circumferential pelvic pressure. Their study demonstrated conducted in a very controlled, standardized environment.

compression at the greater trochanter produced the smallest Two senior pelvic surgeons ensured appropriate placement
intraperitoneal pressure change, which suggests that intra- and use of each intervention. This has the advantage of reduc-
21
peritoneal pressure is of little use in measuring binder effect ing bias or errors due to suboptimal binder use. In clinical
when binders are placed correctly at the greater trochanter. We practice, up to 39% of pelvic binders are placed inaccurately,
38 | JSOM Volume 17, Edition 3/Fall 2017