Page 78 - JSOM Winter 2019

Training Burden events, and lower limb amputation alongside challenges using
There is no quality material in the literature objectively assess- interventional radiology while REBOA is deployed. 28–31 It is
ing the training burden prior to successful use of the AAJT. also reasonable to suggest that there is a significant risk of in-
However, anecdotally, and from author experience, the device fection at the REBOA insertion site, which will not be present
is easy to use and requires little specialist knowledge or train- in external compression devices; this is likely to be especially
ing. It has a quick learning curve and does not require ancil- true if a prehospital battlefield cut-down is used for access.
lary equipment such as ultrasound for successful application.
In all interventions that occlude the aorta. whether it is exter-
One of the major limitations to training with the AAJT placed nal compression, direct clamping, or intraluminal occlusion,
in the abdominal position is that of pain when correctly ap- there is concern surrounding the effect on release secondary to
plied to a healthy user—this could prevent correct tighten- an ischemia–reperfusion injury. Animal models for the AAJT
ing, which then may have an effect on real-life use. One must demonstrate respiratory and metabolic derangements follow-
consider that the application of the C-A-T is also painful; in ing release. 15–17 It has been observed that the AAJT is tolerable
training, it is not fully tightened yet the device is still effec- in spontaneously breathing swine; however, on release, cardio-
tively used in real life scenarios. One could of course use a vascular and respiratory support can be required to prevent
simple manikin, but there will then be no feedback to reinforce cardiac/respiratory arrest. Notably, Kheirabadi et al. demon-
correct placement and pressures. Weyhrauch et al., in an at- strated respiratory arrest and death (50%) in spontaneously
tempt to overcome this, have developed a manikin with sensor breathing swine following release after a 2-hour application
feedback, which gives the user real-time feedback on place- time. 15,17 It is reasonable to suggest that the AAJT can be ap-
ment and tourniquet effectiveness, although to the author’s plied to the spontaneously breathing patient, but it must only
27
knowledge, this device is not widely available on the commer- be removed after resuscitation in an environment capable of
cial market. When widespread adoption of the AAJT occurs, providing respiratory and cardiovascular support, which may
this could be a key adjunct to successful training. UK military include invasive ventilation, hemofiltration, and use of ino-
ethical approval (MODReC) has been requested for a study tropes, thus attempting to mitigate this complication. Addi-
15
looking at the effectiveness of training UK combat medical tionally, one should limit application to less than 1 hour as per
technicians (CMTs) to apply the device on human volunteers. manufacturer guidance.

Safety Profile Axillary and Groin Use
It is recommended by the manufacturer that the AAJT in these
The AAJT is both a US Food and Drug Administration– locations is used for a maximum of 4 hours. In human healthy
approved and a CE-marked product. The manufacturer lists volunteer studies there have been no significant long-term side
absolute contraindications as pregnancy and known abdom- effects or complications. Pain is commonly reported at site
inal aortic aneurysm. 3 of use in healthy volunteers. The two case reports in axilla
and groin utilization revealed no complications following its
Placed at the Aortic Bifurcation use. 21,22
The manufacturer advises use at the aortic bifurcation of no
more than 1 hour. The only case report of abdominal use re- Pelvic Trauma
veals no significant complication related to AAJT use at 48
hours after use. Additionally, in studies on healthy human Patients with hemodynamic instability despite resuscitation
14
volunteers where the AAJT is placed only for a short time, secondary to pelvic injury are notoriously difficult to manage.
there have been no significant long-lasting reported compli- Currently, first-line management in the prehospital environ-
cations. Much of the current safety and physiological data ment or within the emergency department is to apply a pelvic
come from animal models. These animal models suggest that binder to act as a hemorrhage control device. This device aims
the AAJT can be used for up to 1 hour with no long-term det- to “close the book,” which decreases pelvic space, promotes
rimental effects. This is in keeping with the manufacturer ad- tamponade of venous bleeding, and reduces fracture move-
vice. 16,17 As time extends beyond 60 minutes, there is evidence ment thus reducing secondary hemorrhage and clot disrup-
that harm occurs. tion, but pelvic binders have limited effect on pelvic arterial
bleeding. 32
The most scientific study is by Kheirabadi et al., who followed
their swine for up to 2 weeks postevent. In this study, they We strongly advocate the continued use of prehospital pelvic
revealed that the 60-minute group had no lasting side effects, binders. However alongside a pelvic binder the AAJT may
the 120-minute group developed persistent hindleg paraplegia have a beneficial role. The AAJT can be applied at the same
and urinary retention with ischemic necrosis of lumber mus- time as the pelvic binder and in cases of continued hemody-
cles, and within the 90-minute group, half developed paraple- namic instability be inflated to achieve control of hemorrhage
gia and 2 of 6 had widespread necrosis of the colon and/or (Figure 1). An additional role of AAJT could be in achieving
rectum. Brännström et al. subjected swine to 240 minutes of stability for transfer to a specialist trauma center. Although
16
AAJT application. They found that in the intensive care setting, external fixation or pelvic packing can achieve hemorrhagic
the reperfusion injury on release was survivable, but there was control, Interventional Radiology (IR) is increasingly the first
evidence of significant abdominal organ damage (microscopic choice management strategy in some centers. This can provide
and macroscopic). Long-term follow-up was not performed, a logistical challenge as in centers not set up for this—time
and spinal cord function was not assessed. These data must to IR can be as long as 5 hours. The AAJT could therefore
33
17
be examined together with published REBOA device–related be used as a bridging device to facilitate the transfer of such
mortality (0.8%) and morbidity information that includes patients from a small or remote location, to a Level 1 Trauma
aortic injury, femoral artery injury requiring repair, embolic Centre.

76 | JSOM Volume 19, Edition 4 / Winter 2019