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ECMO was rarely perfomed during the recent combat op- Trained, experienced personnel are also absolutely necessary
erations and mostly at higher echelons of care for patients for successful ECMO implementation. Many formal hospi-
sustaining acute respiratory distress syndrome. 19–23 Turner et tal-based ECMO teams consist of providers from an array of
al reported only three ECMO procedures documented at different specialties, including cardiac surgeons and cardiac
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Role 3 MTFs during 15 years of combat operations in Iraq anesthetists, perfusion services, intensive care nursing, and
and Afghanistan. Ten US casualties (four of them cannulated others. 25,16 For battlefield ECMO, Macku et al. previously
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in the war zone) were also successfully treated with either proposed a larger group of specialists, including a cardiac and
venovenous ECMO or pumpless extracorporeal lung assist vascular surgeon. The team used for the present report con-
and underwent strategic evacuation. 20,23 These isolated reports sisted of four members: two anesthetists, a military (trauma)
represent the only description of ECMO or E-CPR cases in a surgeon, and a nurse. The optimal configuration of a potential
combat zone that to date have been published in the literature. austere E-CPR team will require additional study, however, be-
cause several studies have also demonstrated that nonsurgeons
The present work demonstrates the technical feasibility of with appropriate training can safely perform vascular cannu-
E-CPR for use on the modern battlefield. During the field exer- lation and initiate ECMO. 16,27 Additional vascular training is
cises, simulated out-of-hospital CA was achieved in austere set- likely very important to support expediency with both cannu-
tings, followed by staged care. Two animals were transported lation and coping with potential vascular-access complications.
to Role 2 with adequate levels of perfusion pressure without ac-
cess-related complications. Although nominally admitted alive Although cannulation procedures and ECMO are typically per-
(normal-range MAP on admission to Role 2), both animals formed at facilties with capabilities substantially greater than
had artificial circulation and were progressively deteriorating those in the typical Role 1 setting, only hand-carried devices
with uncontrolled acidosis and anemia. To support circulation, (i.e., ECMO machine, ventilator, gas cylinder) were used by the
large volumes of crystalloids were used; however, early blood personnel augmenting this stage of care in the present report.
replacement has a potential for use in E-CPR. In a study in- This expanded prehospital military capability goes along with
vestigating TCA in animals, Barnard et al. demonstrated that the current paradigm of special operations surgical/resuscitative
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animals that had undergone selective aortic arch perfusion and teams that have evolved to provide surgical capability farther
been resuscitated with fresh whole blood had higher rates of forward to the battlefield. 28,29 Among the vascular access pro-
ROSC and survival than did those resuscitated with Ringer cedures described on the study animals, surgery was attempted
lactate or that underwent REBOA without an additional per- in one animal to achieve more proximal access because of the
fusion modality. Because of the high serum concentration of failure of femoral cannulation. The surgeons in this study pro-
potassium administered to initiate CA in our study, ROSC was tocol persisted with vascular access alternatives despite recur-
unlikely to be achieved and hence was not considered to be a rent challenges, but this practice might not prove feasible in a
primary endpoint. Although additional study is required, these real-world casualty care event. In that context, such persistent
findings suggest that ECMO for very select patients may avoid failure to achieve access would demand an earlier shift in focus
mortality and support transfer to Role 3, where more compre- toward other life-saving techniques and interventions. 30
hensive resuscitative care can be provided.
The specific equipment to facilitate E-CPR continues to evolve.
It is important to note that ECMO remains a highly technical At present, ECMO requires an appropriate perfusing machine,
and technology-dependent intervention. Tisherman et al. re- additional oxygen supply, and cannulae. The portable perfu-
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cently raised critical questions related to development of an sion device used in the present study satisfies the portability
effective system to integrate E-CPR in a continuum of care, and functionality needs for prehospital scenarios. To reduce
including such important factors as selection of patients, the weight, a portable oxygen concentrator or generator might be
experience and skills of personnel, and equipment. potentially used, but because it was unavailable in this instance,
an additional oxygen gas cylinder was used. The choice of a
Combat wounded are a unique cohort of patients. Effective draining (i.e., venous) cannula in the present study was found
TCCC protocols provide the best chances for the combat to be critical because a short cannula was unable to adequately
wounded to survive, but the value of battlefield CPR remains drain blood from the inferior vena cava compressed by elevated
a matter of active debate. Present TCCC doctrine does not abdominal compartment pressure. Further, the inability to can-
advocate the use of prehospital CPR when no pulse, ventila- nulate the femoral artery in animal No. 3 demonstrates the need
tion, or other signs of life are appreciated. These guidelines to have an enlarged kit containing cannulae of different sizes
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suggest that CPR may be attempted during tactical evacuation and lengths to meet the anatomic configurations encountered.
only if transportation time is minimal and the casualty has no
obviously fatal wounds. In accordance with sound prehosp- Equipment for adjunctive CPR in a harsh military setting is
tial combat casualty practice, the obvious sources of hemor- another issue for consideration. The Lucas compression device
rhage must be primarily controlled and other immediately used in the present study is not currently familiar in the mod-
life-threatening conditions addressed. ern battlefield and may be too large to be included in a typi-
cal combat medic kit. It may, however, improve the ability to
Exploration of the value of E-CPR in the combat setting will deliver required hands-free compression, as supported by the
require judicious consideration of the potential role of antico- finding here that one-third of closed CPR time was required en
agulation early after control of obvious hemorrhage sources. route. Effective CPR for these durations by hand compression
Although some leading centers have initiated ECMO for is unlikely to be as effective as that of device-assisted CPR,
trauma without systemic anticoagulation, optimal practice thereby potentially worsening an outcome.
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in this regard is not well elucidated. Modern heparin-bonded
cannulae and circuits may play a particularly valuable role in This feasibility report has important limitations that must be
the trauma setting. acknowledged. First, this is a pilot, small-sample-size study

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