International Journal of Clinical Medicine, 2013, 4, 511-524
Published Online December 2013 (
Open Access IJCM
Helicopter EMS beyond Trauma: Utilization of Air
Transport for Non-Trauma Conditions
Stephen H. Thomas, Lori J. Whelan, Emily Williams, Loren Brown
Department of Emergency Medicine, University of Oklahoma College of Medicine, Tulsa, USA.
Received October 7th, 2013; revised November 1st, 2013; accepted November 20th, 2013
Copyright © 2013 Stephen H. Thomas et al. This is an open access article distributed under the Creative Commons Attribution Li-
cense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Helicopter Emergency Medical Services (HEMS) use in civilian medical transport has its roots in th e use of rotor-wing
trauma transport in the military setting. Much of the literature and ev idence based on the use of HEMS is therefore re-
lated to scene and interfacility transport of injured patients. Regionalization of care and increased understanding of time-
criticality of various non-trauma co nditions has contributed to growing utilization of HEMS for non -trauma conditions
over recent decades. It is common for HEMS to be utilized for a variety of non-trauma situations ranging from neonatal
and obstetrics transports to cardiac and stroke transports. The purpose of this review is to overview the use of HEMS for
non-trauma, focusing on situation s in which there is evidence addressing possible HEMS utility.
Keywords: Helicopter Emergency Medical Services; Air Medical Transport; Prehospital Care
1. Introduction
This discussion strives to overview evidence addressing
benefits accrued by utilization of helicopter EMS (HEMS)
for non-trauma patients. The primary goal will be to
analyze HEMS literature to describe, qualitatively and
quantitatively, potential benefits of air medical transport
for medical and non-trauma populations.
The discussion commences with background informa-
tion that is provided to facilitate interpretation of HEMS
studies. Next, the non-trauma HEMS outcomes in litera-
ture are introduced with division s by diagnostic catego ry.
The review concludes with the summary and suggested
directions for future investigation.
The HEMS outcome deb ate’s long evity and vigo r con-
stitute sufficient impetus for evidence-based exploration
of whether there is benefit to air medical transport. For-
tunately, some detailed exploration of existing data has
been executed. One excellent example is a report in 2007
from the independent Institute of Health Economics,
prepared for the Canadian health ministry in Alberta.
These authors, after reviewing all available studies from
the year 2000, concluded: “Overall, patients transported
by helicopter showed a benefit in terms of survival, time
interval to reach the healthcare facility, time interval to
definite treatment, better results, or a benefit in general”
The Alberta publication addressed a variety of patient
types, but most direct HEMS outcomes’ information (in-
cluding the only Cochrane review of HEMS outcomes)
addresses HEMS use for injured patients [2]. Thus, there
appears to be a relative paucity of information overview-
ing HEMS use fo r n o n -t rau ma.
Why a review article on HEMS non-trauma uses? Per-
haps the most important reason is that, as to the maturity
of the applicable evidence, air medical transport is
broadly employed for non-trauma cases. The National
Association of EMS Physicians (NAEMSP) Guidelines
for HEMS use includes a variety of recommendations
(although acknowledging lack of solid evidence base) for
HEMS dispatch for non-trauma [3]. Furthermore, as long
ago as 2003 a Chest editorial [4] observed that “In many
communities, emergency air medical systems have be-
come an integral part of the practice of cardiology and
critical care medicine.” The Chest authors aver that “We
firmly believe that air medical transport is a safe means
for transport of cardiac patients and should be considered
for patients who require transfer to more specialized
centers for additional diagnostic and therapeutic inter-
ventions.” There is also a long history of HEMS use for
non-trauma surgical cases. An article from a quar-
ter-century ago described the use of air transport for pa-
Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions
tients with ruptured aortic an eurysm [5].
If HEMS are going to be used for non-trauma, then it
is important to assess and optimize resource use by iden-
tifying cases in which benefit is most likely to occur.
This is important because of the highly visible concentra-
tion of costs that are present with helicopters. Some in-
vestigators have assessed regional costs of HEMS to be
no higher than those associated with response-time-
equivalent (multivehicle) ground critical care coverage
[6]. However, the perception is (and likely will long be)
that air medical transport is expensive. Use of an expen-
sive resource should be accompanied by an assessment
of justification for such use.
Since few argue that HEMS benefit is always predi-
cated on time and logistics, consideration of HEMS out-
comes’ evidence touches upon the broader subject of lev-
els of care beyond advanced life support (ALS) in the
prehospital setting. Thus, this arena will also be dis-
cussed herein.
For purposes of consistency within this review, “pre-
hospital” is interchangeable with “out-of-hospital” in
order to encompass both scene and interfacility transports.
HEMS crews’ extended practice scope, even in the US
where crews often do not include physicians, facilitates
consideration of benefits to advanced care [7].
While most non-trauma HEMS use falls within the
realm of secondary (interfacility) transport, the items in
this review are not limited in scope to interhospital
transfers. Suggestion of potentially growing indications
for HEMS “scene” transports of non-injured patients is
provided by an evolving literature describing significant
utility to direct HEMS response to patients such as those
with acute coronary syndrome (ACS) or ischemic stroke
Many questions remain unanswered about HEMS.
However, there is a body of evidence addressing HEMS’
potential outcome impacts, which is often paid insuffi-
cient attention. This discussion’s goal is to provide in-
formation on non-trauma HEMS use, in order to aid in-
terested parties to understand the evidence pertinent to
the outcomes dialogue. It is hoped that the review will
assist those physicians and systems planners who are
pursuing appropriate and judicious employment of po-
tentially life-saving HEMS resources.
2. Outcomes Assessment in HEMS
This section covers the approach to considering HEMS’
impact for non-trauma indications. It’s necessary for
planners to incorporate HEMS “outcomes” on patients,
EMS systems, and regionalized care networks. The sub-
ject of mechanics of outcomes assessment in HEMS has
been addressed in detail in a 2012 review [12]. High-
lights and recent advancements will be covered in this
One important recent development is a joint position
statement promulgated by the Air Medical Physicians
Association (AMPA), the National Association of EMS
Physicians (NAEMSP), the American College of Emer-
gency Physicians (ACEP), and the American Academy
of Emergency Medicine (AAEM) [13]. The position
statement, published at the end of 2013, includes some
important consensus ideas about the state of the art with
HEMS; the document also gives directions for forward
movement of HEMS development. Among the important
points made in the consensus statement are some with
relevance to this review. For instance, the consensus
statement avers that for many time-critical situations,
particularly those for which there is time-windowed
therapy, the measurement of HEMS’ impact on outcome
is best focused on delineating the amount of time saved
by air transport [13].
Before moving to other outcomes, a note on HEMS
safety is appropriate. Th e recent jo int organization al con-
sensus statement includes the need to emphasize safety
and also the importance of separating aviation deci-
sion-making from the clinical arena [13]. The subject of
aviation safety and HEMS’ flight-related risks is so im-
portant that a even a cursory overview does not serve.
Interested readers are directed to the work of experts
such as Blumen from the University of Chicago [14].
Direct patient outcomes benefits are most important. If
there are none, then there is low likelihood that HEMS
use is appropriate or cost-beneficial when considered on
a system basis. For patient-centered considerations, mor-
tality is the most important and most commonly studied
endpoint in HEMS trauma studies [12]. For non-injured
patients, however, there are few easily applied scales to
adjust for the inh erent acuity differences between gro und
and air transported patients. Thus, direct assessment of
mortality is quite difficult since analysis cannot control
for the unadjusted (higher) mortality risk of the air trans-
port cohort. Therefore, for non-trauma cases HEMS’ pa-
tient benefits tend to be measured indirectly, via end-
points that are either secondary (e.g. myocardial muscle
salvage) [15] or surrogate (e.g. time-to-cath lab) [16].
Fortunately, for at least two commonly transported diag-
nostic populations (cardiac and stroke), there are objec-
tive data that allow direct correlation of time savings to
improved mortality and morbidity [17,18].
While patient-centered outcomes are of course most
important, other “outcomes benefits” (e.g. systems bene-
fits) may also contribute to potential justification for in-
cluding HEMS in a system. These benefits are comple-
mentary to direct patient benefit. HEMS can allow for
improved regional performance in getting non-trauma
patients to definitive care such as pro vided by stroke cen -
ters, cardiac catheterization labs, or operating rooms
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Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions 513
In the absence of randomized controlled trials-gener-
ally viewed as nonfeasible for HEMS research [13,21]
one approach for non-trauma is to demonstrate that use
of HEMS allows for “far-away” patients to achieve the
same good outcomes as are achieved for those who live
near hospitals. This approach has been executed for car-
diac [22], obstetric [23], and neonatal [24] patient popu-
lations, with findings that HEMS allows for outcomes
that are as good as those seen in patients presenting pri-
marily to tertiary care centers.
The remainder of this review addresses HEMS use for
various non-trauma diagnoses. There are varying depths
of evidence for various utilizations, but the goal of the
discussion is to include all non-trauma situations for
which there are at least some relevant studies. The most
data are available for cardiac patients, with stroke fol-
lowing. Sparser but still directly relevant evidence is
available for non-trauma surgical cases, pediatrics, and
obstetrics; these populations are addressed in order in the
following sections of this review.
3. HEMS for Cardiac Patients
The primary utilization of HEMS for cardiac cases is in
the setting of ACS, most notably ST-elevation myocar-
dial infarction (STEMI) needing percutaneous coronary
intervention (PCI). Other diagnoses are certainly impor-
tant, as outlined in the NAEMSP guidelines for helicop-
ter use [3], but air transport’s logistics advantages have
obvious potential for frequent use in time-critical
3.1. Patient Safety
In addition to the obvious and overriding importance of
aviation safety (outside the scope of this review), lie
questions about patients’ medical safety during air
transport. Early data [25] indicating catecholamine rise
during air medical transport suffered from lack of appro-
priate ground EMS controls, and sympathetic “surge”
never became an area of concern for HEMS. However,
the early questions did prompt consideration of other
potential dangers asso ciated with air transpo rt. The majo r
issues to be considered were electrical and vibrational.
Electrical considerations were focused on the ability of
pacemakers to function properly in the aviation setting.
In considering theoretical and practical concerns (e.g.
pacemaker separation of patients’ intrinsic electrical sig-
nals from transient environmental signals), specialists in
cardiac transport were able to definitively demonstrate
HEMS safety for paced patients [26].
When questions about the electrical environment were
settled, focus turned to the movements and vibrations
attendant to helicopter transport. In an era in which
thrombolytic therapy was the primary treatment for
STEMI, there were understandable concerns that high-
frequency constant vibrations (such as from jet engines)
could mediate increased risk of post-lysis bleeding. For-
tunately, these risks turned out not to be encountered or
manifest in increase in complication rates. Seminal work
by Fromm et al. [27] in Texas (US), whose HEMS unit
provided large numbers of post-lysis STEMI transports,
demonstrated there was no increased bleeding or other
risks in the post-lysis population.
With patient safety being demonstrated, HEMS clini-
cal researchers’ next task was to ascertain what outcomes
benefits may be accrued with use of cardiac air transport.
The benefits focused upon were primarily related to
STEMI and time savings; these are covered next.
3.2. Moving STEMI Patients to the Cath Lab
In terms of cardiac patient transports and time savings,
there is increasing emphasis on getting patients with
myocardial infarction to primary PCI as the treatment of
choice if a 90-minute first-door-to-balloon time can be
met; expedited prehospital care—including HEMS—will
play an important role in cardiac care systems [28,29].
One of the major dichotomous benefits of HEMS is
therefore simply getting patients to primary PCI within
the window of benefit.
Unlike the case for some diagnoses, for which crew
expertise is a major (and perhaps the most important)
factor mediating HEMS’ outcome improvement, for PCI
transports the key appears to be time savings [16]. Well
over a decade ago, cardiologists were positing that the
time savings and associated earlier intervention was re-
sulting in myocardial salvage and improved HEMS-re-
lated morbidity outcomes such as a 2-day decrease in
hospital length-of-stay [15].
In fact, early HEMS studies helped establish the over-
all desirability of primary PCI as an alternative to throm-
bolytic therapy. A major study (Air PAMI) randomized
patients to community hospital lysis or transport (by ei-
ther ground or air) for primary PCI. Air PAMI results
were fascinating: the transported patients took much
longer to get to definitive therapy (155 vs. 51 minutes)
but had a 6-fold improvement in outcome as compared to
those who were lysed. The study results were sufficiently
compelling even on interim analysis, that the investiga-
tion was halted before full enrollment targets were
reached [30].
Ongoing study next demonstrated that despite the im-
portance of meeting the dichotomous endpoint of “ar-
rived at the cath lab in time for PCI,” there were still
benefits to be gained by time savings ev en within th e PCI
window. Time really is myocardium. Experts have writ-
ten that the maximal benefit of primary PCI is accrued in
the initial 60 minutes [31]. It is also known that each
15-minute decrement in time to PCI, from 150 minutes
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Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions
down to <90 minutes, is associated with 6.3 fewer deaths
per 1000 patients treated [17]. Data from 2009 suggest
that the inflection points of the time savings and mortal-
ity benefit curve, are somewhere around 45 and 225
minutes; this means that time savings is associated with
mortality benefit when patients get to PCI within 45 to
225 minutes of initial “door” time [32]. Considered from
another perspective, each 30 minutes’ additional ische-
mia time increases mortality by 8% - 10% [33]. Time
savings on this level are distinctly possible with appro-
priate use of HEM S [16].
3.3. HEMS as Part of Cardiac Care Systems
Improvements in times for individual patients inevitably
lead to consideration as to how HEMS can be best inte-
grated into systems of cardiac care. Work from both the
US and Europe demonstrated the overarch ing cap ab ilities
of HEMS as a tool for extending the reach of STEMI
care networks for rapid provision of PCI [22]. There is
growing system-based recognition of importance of
transporting STEMI patients for PCI. A consortium panel
of US EMS medical directors has identified as an evi-
dence-based benchmark for quality prehospital care, the
transport of STEMI patients to primary PCI within 90
minutes of EKG diagnosis [34]. Recent meta-analysis
confirms the substantial outcomes benefits, in terms of
both systems-level mortality and morbidity, of timely
transfer of STEMI patients for mechanical reperfusion
[35]. For some regions and patients, HEMS provides a
vital capability to meet this benchmark.
Just as focus on the entire process from symptom onset
to opening of infarct-related artery is important for plan-
ners of acute cardiac care, focus on pre-HEMS and post-
HEMS activities is necessary to maximize transport-re-
lated time savings benefits. In one of the most successful
demonstrations of HEMS incorporation into a regional
cardiac care system, Blankenship et al. [36] used a “be-
fore-and-after” approach to examine endpoints of time
savings and health outcomes associated with institution
of a new triage and HEMS transfer system. The system’s
goal was to expedite community hospital evaluation and
referral of STEMI patients to a PCI center. Protocol
changes effected midway through the study included: 1)
community hospital STEMI care changes emphasizing
time savings (e.g. elimination of heparin and nitroglyc-
erin infusions), 2) simultaneous PCI lab and HEMS acti-
vation from a single call to the receiving center, and 3)
bypass of the receiving center’s Emergency Department
(ED) after HEMS transport.
In the Blankenship study [36] from Pennsylvania, for
the main endpoint (community hospital presentation to
wire-crossing time), the “after” period was associated
with significantly shorter ti mes (105 vs. 205 minutes, p =
0.0001). Time savings were achieved by faster HEMS
dispatch (from 35 to 16 minutes) and streamlining time
intervals between HEMS dispatch and PCI center arrival
(from 56 to 45 minutes). The proportion of patients with
door to wire-crossing times under 90 minutes increased
from 0% to 24%, and the percentage with door to wire-
crossing times under 120 minutes also increased (from
2% to 67%). The study successfully made the point that
with use of time as a surrogate endpoint, and one that
was well-founded on current physiologic understanding,
HEMS could be an important component of a system of
care. The promising system-based results of the Blanken-
ship group were replicated in a 2013 study that found
that combination of HEMS with other streamlined refer-
ral processes resulted in a trebling of likelihood of pa-
tients getting door-to-balloon time within the desired
90-minute window [37].
The Pennsylvania results have been reproduced else-
where. A study from Ohio (US), found that patients were
nearly 3x more likely to have door-to-balloon times un-
der the 90-minute target when they were transported us-
ing a streamlined referral process (that included HEMS
“autolaunch”) [37]. A Japanese report finds that, com-
pared to ground ambulance transport, HEMS use in their
particular system is associated with a half-hour’s decre-
ment in times to angiographic evaluation and interven-
tion [9]. A preliminary report on simultaneous HEMS
dispatch and tertiary care hospital cardiac cath lab activa-
tion by ground EMS providers making STEMI diagnosis
during transport to a referring (non-PCI) hospital, found
the referring hospital time was reduced from 79 to 31
minutes [20]. Others have also demonstrated the signifi-
cant time savings able to be accrued from prehospital
activation of HEMS for transport directly to the cath lab
[38]. For systems-based use of HEMS, the entire system
from prehospital through cath lab needs to be considered,
and the role of helicopter transport carefully considered
for potential integration as part of the overall care net-
3.4. Cost-Effectiveness
Recently, a group from the large rural US state of Okla-
homa has generated preliminary data intended for ulti-
mate use in cost-effectiveness calculations. In this paper,
the authors were the first to specifically tie time savings
to estimated HEMS-mediated mortality improvement
[16]. Time savings accrued with HEMS as compared to
ground transport were calcu lated estimated using what is
becoming a standard geographical information software
(GIS) approach [21]. The authors found substantial time
savings. Since the novel study methodology was imper-
fect, the limited overall conclusions were that the data
should serve as the basis for a larger analysis (now on-
going) to assess whether the number-needed-to-treat
(NNT) of 59 is consistently estimated in different areas.
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Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions 515
If the results of the initial study are replicated in the lar-
ger analysis, the NNT of 59 has utility as a variable in the
cost-effectiveness analyses important for HEMS and
Systems planners designing cardiac care networks are
well-advised to incorporate air (as well as ground) trans-
port into planning. The importance of judicious planning
has been demonstrated by work from Ohio (US).
McMullan et al. [39] found that use of HEMS transport
for cardiac patients is no guarantee of arrival to cath labs
within recommended time frames. HEMS is potentially
important as a part of a cardiac care system, but the air
medical resource must be used wisely.
A 2010 study revealed that centralization of cardiac
catheterization resources, with appropriate build-up of
EMS transfer systems, is significantly more cost-effec-
tive than construction of multiple cardiac catheterization
centers; the authors note that 20% of Americans live
more than an hour away (by ground) from a cardiac
catheterization center [40]. Complementary information
is provided by a report by Peterson et al. [41] that HEMS
integration into a cardiac care system allows for diagnos-
tic catheterization to be performed at community hospi-
tals, with rapid air transport for interv entional procedur es
when needed. All of these data contribute to a co nclusion
that air medical transport does have a role in optimizing
cardiac care regionalization.
3.5. HEMS for Other Cardiac Cases
The time advantage is also accrued for patients other than
those being transported for primary PCI. For patients
failing PCI at referring hospitals, HEMS has demon-
strated utility as a backup system for rapid transfer for
urgent surgical revascularization [42]. Work from the
TRANSFER-AMI group suggests that expedited transfer
for mechanical intervention after community hospital
lysis is associated with a 50% reduction in a 30-day
composite endpoint (death, reinfarction, recurrent ische-
mia/reinfarction, CHF, or shock) [43].
Another category of “cardiac” patients that has re-
ceived attention in the HEMS literature comprises those
who have had cardiac arrest. In this broad category, ini-
tial work proved true, the common-sense notion that
HEMS was not indicated for patients in persistent non-
traumatic cardiac arrest [44]. The authors of that study
noted some potential logistics advantages (e.g., improved
availability of ALS in rural settings) entailed in rural
HEMS utilization, but they make a strong argument
against HEMS benefit for patients in arrest at time of
HEMS activation. For those patients who are resuscitated
from cardiac arrest, though, the outcome is different;
work by Werman et al. [45] demonstrates that appropri-
ately dispatched HEMS can be beneficial in post-arrest
4. HEMS for Neurological Patients
The mantra “time is brain” evolved more recently than
“time is myocardium,” but it is no less important. From
early information that described benefits of time savings
(such as with stroke patients) in terms of hours [46], the
state of the evidence now supports time savings on
smaller scales [18]. When considering how to streamline
care on the level of these smaller scales—15 minutes’
increment can make a difference—HEMS becomes an
asset to consider.
4.1. Patient Safety
As was the case for cardiac cases, one of the first items to
address was safety. For stroke patients in whom post-
thrombolysis hemorrhagic conversion is a major concern,
there were safety questions about helicopters and move-
ment (including vibration). Two 1999 studies by Chalela
[47] and Conroy [48] established that even in post-lysis
patients, there were no increases in rates of stroke com-
plications such as bleeds. In demonstrating the safety of
HEMS use for even the sickest stroke patients, Conroy
further posited that the relatively minimal “packaging”
required for neuro patients translated into ideal setup for
HEMS to save time [48].
4.2. Time Savings
It has for over a decade been postulated (with support
from pooled analysis data) that there is stepwise out-
comes improvement associated with each 90-minute im-
provement in stroke lysis time (to 270 minutes) [49]. As
previously noted, the time frame for which incremental
improvement is achieved with more streamlined therapy
has continually narrowed. In 2013, Saver et al. [18] drew
a direct line between improved functional and vital out-
come and incremental time s avings of as little as 15 min-
utes. Given clear data from other facets of the HEMS
literature that air medical transport very often results in
time savings of this magnitude [16,50], it seems quite
likely that stroke care networks will continue to benefit
from appropriate use of HEMS.
Time savings due to HEMS is relatively easy to char-
acterize for stroke patients, but streamlining pre-neu-
rologic center times can potentially aid a breadth of pa-
tients. There are few data describing HEMS crews’ sav-
ings of time for other neurological conditions, but it is
nevertheless the case that (at least occasionally) such
time savings are likely to occur and are a critical con-
tributor to improved outcome.
4.3. HEMS as Part of Stroke Systems
Stroke patients were among those emerging time-critical
populations for whom regionalization of care translated
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Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions
into advanced therapies’ being available primarily at re-
gional centers, and even in the late 1990s air medical
transport seemed well-positioned to be a part of stroke
A Resource Document for a position statement of the
National Association of EMS Physicians recommends air
transport of stroke patients if the closest fibrinolytic-
capable facility is more than an hour away by ground
[51]. The American Stroke Association Task Force on
Development of Stroke Systems [52] identified HEMS as
an important part of stroke systems. The report states
“Air transport should be cons idered to shorten th e time to
treatment, if appropriate.”
Authors writing about the utility of HEMS in stroke
care systems generally refer to the ability of HEMS to
“extend the reach” of tertiary care centers providing
time-critical care [19]. The emphasis on time is not
unlike the situation with STEMIs: highly trained crew
with critical care experience is of course important, but
the main contribution of air transport is expedited
movement of patients to time-windowed therapy.
The case for HEMS use to optimize stroke lysis rates
has been convincingly made in a national registry-based
study from Austria. Reiner-Deitmeyer et al. [53] used
“administration of thrombolytic therapy” as their end-
point, focusing on the capability of air transport to get
patients to lysis-capable centers. The authors found that
both scene and interfacility HEMS transport allowed for
higher thrombolysis rates, and that scene HEMS re-
sponse was associated with the highest chances of stroke
patients’ receiving thrombolytics within 90 minutes of
sy mptom onset.
The Austrian study’s findings regarding scene trans-
ports for stroke confirmed earlier findings from a rural
US region (north Florida and southern Georgia). Over a
decade ago, Silliman et al. [54] explored the contribution
of HEMS to facilitation of patient transport from rural
“scenes” to a stroke center. HEMS was called to the
scene for patients with suspected stroke, and the diagno-
sis was usually correct (stroke was ultimately diagnosed
at the receiving center in 76% of cases). During the study
period, stroke transports comprised 4% of the HEMS
service volume, but HEMS-transported stroke patients
accounted for nearly a fourth (23%) of all patients re-
ceiving stroke lysis at the receiving center. In short,
HEMS was not overused, stroke was not overdiagnosed
by prehospital personnel, and many patients were lysed,
who would otherwise have not had a chance to receive
time-windowed therapy.
The lessons on “scene” calls for stroke have been dem-
onstrated by others as well. For example, the French have
reported HEMS response to cruise ships at sea, enabling
time-critical and successful lytic therapy for stroke [55].
The authors from the Florida study and also those from
Austria join others in demonstrating that a strictly ap-
plied stroke triage protocol (roughly based on the trauma
triage model) can widen a stroke center’s coverage area.
Even in highly developed urban systems, there is some
role for judicious employment of air medical resources to
operationalize the regional adherence to the adage “time
is brain [8,56].” _ENREF_38.
From the systems perspective, HEMS is an important
part of stroke care networks in which outcomes are im-
proved with stroke care in specialized centers [57]. Addi-
tion of air medical resources into logistics calculations
halves the numbers of Americans who lack timely
(within one hour) access to a primary stroke center (from
136 million to 63 million) [58].
4.4. Cost-Effectiveness
The fact that there is advantage in administering stroke
thrombolytic therapy in a more timely fashion is only
true to a certain time point. Even for stroke lysis proto-
cols that allow for “late” thrombolysis (up to 4.5 hours
post-symptom onset) there remains a “wall” that is not
safely crossed. If the patient doesn’t get to a lysis-capa-
ble center within a certain time frame, the opportunity at
morbidity- and mortality-improving lysis care is lost.
This strict time-windowing of stroke therapy has gener-
ated an important endpoint for HEMS use in stroke care.
If HEMS can get patients to stroke lysis-capable centers
within a certain time frame, thus allowing them to re-
ceiving this salutary therapy, then that is an important
benefit of air transport.
However, as is the case with any resource, judgment
must be exercised. For cases in which time-windowed
therapy has already been administered, the costs and be-
nefits calculations for HEMS employment are quite dif-
ferent as compared to, for example, movement of lysis-
eligible patients [59].
Just as employment of HEMS for stroke patients
who’ve already received time-windowed therapy may be
questionable, there are data suggesting room for im-
provement in HEMS triage of non-stroke neurological
patients. In a study from Boston (US), authors examined
a variety of neurology/neurosurgery patients (largely
non-trauma) and concluded there were many cases of
HEMS use for neurological conditions that did not in fact
warrant air transport [60].
While data are being developed to address questions in
more detail, there is cost-effectiveness evidence that
strongly supports appropriate use of HEMS for stroke
care. Silbergleit et al. [61] have clearly shown that air
medical transport is quite cost-effective when it enables
stroke patients to receive thrombolytic therapy at receiv-
ing centers.
4.5. HEMS for Other Neurological Diagnoses
A previously cited study from Boston included mention
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Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions 517
of various diagnostic categories (e.g. tumor with mass
effect) for which HEMS transport was potentially useful
[60]. There are few data in the HEMS literature that sys-
tematically address air medical transport use for non-
trauma neurological conditions other than stroke.
For stroke and other neurological conditions, it has
been suggested that the time-critical nature of these dis-
eases lends itself to early intervention by HEMS crews.
Neurologists considering how to get their patients lead-
ing-edge therapy have theorized about potential benefits
of saving an hour or more by having specially trained
HEMS crews intervene upon arrival at referring hospital
5. HEMS for Non-Trauma Surgical Patients
It is somewhat ironic, given the trauma surgery roots of
air medical transport in general, that there is relatively
sparse literature addressing HEMS for non-trauma sur-
gical patients. Most likely this is not because of lack of
occasional HEMS utility in these patients, but rather due
to the heterogeneity of (and difficulty to study HEMS use
in) non-trauma surgical patients.
5.1. Flight Crews and Stabilization of Patients
What HEMS can bring to the table—in part due to ex-
perience with trauma—is the rapid stabilization of surgi-
cal patients and the direct transport of those patients to
the operating room (OR), bypassing the receiving center
ED [5]. Whether the patient has perforated viscus or
splenic rupture from infection, there are theoretical (yet
hard to demonstrate) benefits from expedited air trans-
port. For the most part, these applications of HEMS must
be considered on a case-by-case basis.
Other components of HEMS care that are doubtless
helpful to some general surgical patients are mentioned
in the final section of this review. These “supportive
care” benefits from expert flight crews are as applicable
in critically ill surgical patients, as they are in other di-
5.2. Air Transport of Aortic Aneurysm
There is one group of surgical patients that has time-
criticality, benefits from direct-to-OR transport, and ap-
pears well-situated to gain from rapid HEMS transport:
patients with leaking AAA. Perhaps because this patient
population is so similar to the trauma population with
whom HEMS crews have familiarity, there have been
reports of HEMS use to improve outcome in AAA pa-
In fact, one of the earliest mentions of the concept of
“direct-to-OR” transports came in 1989, when Kent et al.
[5]described their rural state (Alabama, US) experience
with HEMS’ transferring patients directly into the OR.
Subsequent assessment of patients in an urban setting
(Boston, US) by Shewakramani et al. [63] confirmed the
utility of air transport for these most unstable patients.
They made the case that while overall numbers and dif-
ficulty with control groups serves as a barrier to concrete
statistical comparison between air versus ground trans-
port, it seems highly likely that expedited movement of
leaking-AAA patients into the OR is usually desirable.
6. HEMS for Non-Trauma Pediatrics
Asis the case for many other categories of non-tra uma, the
group constituting “pediatrics” is characterized by breadth
that precludes straightforwa rd outc omes studies. What are
present in the pediatric literatu re, are data describing one
major subgroup (neonates) and one major procedural
intervention (airway management). These are considered
in this section. Although the specific-diagnosis informa-
tion for pediatric patients is lacking, the fact remains that
regionalization of care is quite common in pediatric sys-
tems and so it is particularly likely th at HEMS (including
specialized teams) will have a role in pediatric care sys-
6.1. HEMS and Neonatal Systems of Care
Two decades ago, Pieper et al. [64] performed a descrip-
tive analysis of HEMS (and ground) neonatal transfers,
and concluded that HEMS was a critical part of a region-
alized neonatal critical care network. The study was one
of the earliest to establish that air medical transport can be
an important part of neonatal care systems. Subsequent
studies provided an increasing body of evidence sup-
porting a contention that even patients of high acuity and
tenuous stability, such as ventilated neonates, suffer no
adverse effect from air as compared to ground transport
modality [65].
The literature includes population-b ased analyses such
as that of Berge et al. [24] from Norway; the Scandina-
vians described a 14-y ear series of 256 neonatal transports .
They found that the mortality of those transported from
long distances was no worse than those who came by
ground from nearby the receiving centers. Just as
Straumann’s Swiss group [22] had concluded that HEMS
allowed far-away patients to benefit from timely access t o
specialized care and have outcomes just as good as
“close-in” patients, Berge’s study made the case that
HEMS was an “equalizer” of outcomes for neonates who
were located distant from receiving centers.
The Norwegian results included findings of HEMS
crews’ occasional performance of life-saving interven-
tions in transported neonates [24]. The authors also found
that, as compared to the pre-transport time frame at re-
ferring hospitals, air medical transport crews were actu-
ally able to effect improvements in oxygenation, ventila-
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Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions
tion, and circulation during the transport phase. These
results dovetailed with data fro m Miami reported by Hon
et al. [65], who assessed air transport versus ground
transport (by the same university-based transport team)
and found that helicopter flight was not associated with
any worsening in physiology in critical intubated neo-
6.2. Flight Crew Airway Management
For pediatric non-trauma, there are few data on HEMS
transport of non-neonat a l pat i e nt s. There is, howe ve r , one
other source of information relevant to consideration of
air medical transport of pediatrics: the airway manage-
ment literature. Even as ped iatric endotracheal intubation
(ETI) is being increasingly revealed as difficult and fre-
quently unsuccessful in the ground EMS setting [66],
HEMS crews are reporting favorable results. Air medical
transport crews are intervening to provide highly suc-
cessful pediatri c ETI, o ften wi th rates ri valing t hose of t he
in-hospital setting [67,68]. Furthermore, air medical
transport crews are able to intervene after ETI and provide
important adjustments in cuff pressures, insertion depths,
and tube size [69,70].
7. HEMS for Obstetrics
The most cases, the optimal neonatal transport system is
the maternal intrauterine environment. With the principle
that safe and effective obstetrics transports improve both
material and fetal outcome, HEMS use for pregnant pa-
tients has been long d escribed. Initial reports outlined the
safety (in terms of being able to predict which patients
would not deliver while in-flight [71], and subsequent
data outlined time and systems benefits to air medical
obstetrics transports.
7.1. Obstetrics Systems of Care
Traditional “extending the reach of the system” advan-
tages as previously mentioned for other diagnostic
groups, are also applicable to obstetrics patients—HEMS
increases coverage area for centralized maternal-fetal
hospitals. Particularly in areas characterized by a paucity
of maternal-fetal medical specialists, HEMS has been
noted to be a vital contributor to system-wide success in
optimizing outcomes [72]. In addition to the ad vantage of
simply providing access to centralized care, obstetrics
HEMS transports also bring another salient endpoint to
the discussion: minimized out-of-hospital time.
7.2. Minimized Out-of-Hospital Time
Minimization of out-of-hospital time applies to HEMS
use for obstetrics as much as for any transport population.
Over three decades ago, Elliott et al. [23] extoled the
virtues of air medical obstetrics transport not because of
crew capabilities, but rather because of the reduction in
intratransport (out-of-hospital) time as compared to
ground ambulance use. Elliott’s Los Angeles group em-
phasized that achievement of the major goal of having
high-risk patients deliver at receiving centers (thus using
the mother as the “best transport incubator”) was often
only enabled by use of fast-moving helicopters. Aircraft
speed allowed obstetricians to be sufficiently comfort-
able with the low risk of intratransport delivery (unde-
sirable, regardless of transport vehicle) that laboring pa-
tients could be moved to centers with needed expertise in
maternal-fetal medicine. The advantage reported by the
California group was not simply theoretical: referring
facility obstetricians reported that in the absence of
HEMS availability, a quarter of the cases in their series
who were transported by HEMS would have been deliv-
ered at referring hospitals.
In keeping with the sense that maternal and fetal out-
comes are both optimized by having deliveries occur at
specialized centers (rather than rural referring hospitals),
van Hook et al. [71] reported their rural Texas experi-
ence as being similar to that from the Californians.
Whereas the Los Angeles-area group noted traffic con-
gestion was the primary basis for concerns about long
transport times, in Texas the problem was more one of
geography. Over long distances, helicopter transport al-
lowed for safe and effective setup of obstetrics regional
centers to which patients were transported for delivery.
van Hook’s group concluded that their case series sup-
porte d the view “held b y most”, that “maternal/fetal risks
associated with HEMS transport are at most, minimal
As previously mentioned, one of the most important
HEMS benefits for obstetrics is reduction of the chances
of intratransport delivery. This minimization of “out-of-
hospital” time is at least as important as any actual time
benefits of getting patients to tertiary maternal/fetal me-
dical centers of excellence. A Japanese group has pub-
lished their experience that und erlies the priority of mini-
mizing out-of-hospital time. Ohara et al. [72] point out
that their country has limited tertiary care facilities for
maternal/fetal medicine, and that maternal (prenatal)
transport by air is an important part of providing region-
alized care. In assessing a series of 26 HEMS transfers of
pregnan t women to their institution , Ohara’s group found
that HEMS use was associated with savings of 101 min-
utes’ out-of-hospital time (median flight time, 24 minutes;
median estimated ground transport time, 125 minutes).
Certainly, to those who provide care for high-risk obstet-
rics patients, decreasing the out-of-hospital time (and
thus the time frame of risk for intratransport delivery),
savings of 101 minutes is a substantial benefit.
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Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions 519
8. Other Non-Trauma HEMS Issues
The preceding diagnostic situations represent those for
which there are at least some available data directly ad-
dressing HEMS and outcomes benefit. There are many
other situations that are encountered, for which air medi-
cal transport’s crew capabilities and/or logistics advan-
tages may be of benefit to patients or prehospital care
systems. The list of potential types of individual cases for
which air m edical transpo rt could possibl y be useful i s too
far too lengthy to enumerate in this review. Instead, this
final section of the review will address some HEMS
benefits that have potential outcomes utility for myriad
non-trauma patient types.
8.1. Time Savings
There are some areas in which there is growing under-
standing of time-criticality of disease management. One
example of such, is the population of patients with seps is.
with the advent of studies demonstrating improved out-
come from early goal-directed therapy. Recent reviews
of sepsis care emphasize the importance of the six-hour
goal for institution of high-level sepsis care [73]. While
this time frame seems lengthy for air transport in some
urban areas, it is quite conceivable that HEMS crews’
capabilities could help bring therapeutic approaches and
experience to isolated-region patients who would other-
wise miss the 6-hour window.
On the logistics front, those considering potential
benefits of HEMS should not always assume that air
transport doesn’ t save time if ground transport is “kno wn
to be available” at referring hospitals. The authors of a
logistics study from the University of Wisconsin [50]
assessed transport times from their 20-hospital network
and found the average HEMS total transport time over
the study period was at least as good as the best ground
transport time. This finding was despite the fact that for
many hospitals ground EMS was on-site at the time of
transport. Furthermore, the authors found there was
clinically significant time savings for all institutions. For
close-by hospitals, patients accrued an average of 10
minutes’ time savings. From further-away hospitals,
benefits were more marked: HEMS transport times were
up to 45 minutes shorter than achievable by ground
8.2. Critical Medicine Delivery
Perhaps the easiest cases to consider first, are those in
which there is clear logistics and speed capability pro-
vided by HEMS that is simply not available by surface
transport. Examples from the literature include such
situations as use of an aircraft to get a young adult life-
saving prostacyclin for adult respiratory distress syn-
drome (ARDS) [74]. In a similar case, a Canadian group
described use of air transport to get critically needed an-
tidotes (fomepizole in one patient, digoxin antibodies in
another) to patients up to 6 hours faster than would have
been the case had therapy been delayed to ultimate arri-
val at receiving centers [75].
Certainly, case reports do not constitute sole or suffi-
cient basis to justify HEMS existen ce. On the other hand,
these “sporadic” case reports probably reflect a low—but
nonzero—frequency with which air assets’ logistical ad-
vantages mediate significant outcomes improvement.
Just as is the case with trauma, for non-trauma cases
there will occasionally be times wh en physicians making
transport decision s should remember the time and related
benefits accrued only with HE M S.
8.3. Airway and Ventilatory Management
There are data from the broader HEMS literature (in-
cluding from trauma cases) that can inform judgments
about potential benefit from crew expertise. Perhaps the
most obvious of these areas of crew contribution are in
the airway and ventilatory management arena.
The high ETI success rates of HEMS crews have been
addressed elsewhere in this review and in the broader
literature [76]. _ENREF_59 The ability to manage air-
ways with high success rates can accrue advantages to a
variety of non-trauma cases.
Airway expertise from HEMS crews is not limited to
performance of ETI itself. HEMS benefits to patients are
seen even after ETI. This is probably due to ventilator
management, avoidance of hyperventilation, and better
recognition and management of hypoxemia [77,78]. It is
illustrative that HEMS has been shown to improve out-
come for head-injured patients even when HEMS arrives
after ETI has been performed. While focused on head
injury, the work of Davis et al. [79] from San Diego is
telling: even when ETI is performed by ground EMS,
HEMS transport improves outcome as compared with
ground transport because of post-ETI ventilation prac-
Close attention to parameters such as end-tidal CO2, as
well as intensive training and frequent experience with
ventilator management, are likely responsible for the
more stable peri-ETI physiology seen with HEMS as
compared to ground transport [79-82]. While difficult to
measure on a broad basis, it is quite likely that such at-
tention to oxygenation and ventilation is helpful in a va-
riety of non-trauma conditions.
8.4. Critical Care Expertise
In addition to airway management expertise, HEMS
crews bring to bear critical care experience that can (like
ventilator management) be difficult to statistically sum-
marize but which is nonetheless occasionally important.
Open Access IJCM
Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions
For some patients, there is simply no substitute for the
technical capabilities and critical care expertise brought
to bear by many air medical crews [83].
A 2009 study from France demonstrates some of the
mechanisms for HEMS’ improvement in outcome. Berlot
et al. [84] found—in trauma patients, but with likely ex-
trapolation to non-trauma—that as compared to ground
EMS, HEMS transport was associated with improved
outcomes due to better hemodynamic management.
After being neglected for too long as a priority for
acute-care (and prehospital) medicine, the subject of pain
care is receiving its due. Experts in prehospital care have
written that pain care is a valid endpoint in and of itself
[85,86]. Whether due to protocol restrictions on ground
EMS or other factors, HEMS providers tend to be far
more diligent than ground ambulance providers in as-
sessing and treating pain [86-88]. As is the case for air-
way and ventilator management, this component of care
has potential benefit for a breadth of non-trauma patient
9. Conclusion
In summary, HEMS have the potential to bring both crew
expertise and streamlined times to non-trauma patients.
The importance of considering logistics benefits is un-
derlined by even brief consideration of the enormous
breadth of non-trauma situations in which savings of
time can contribute to optimal outcome. As outlined in
the NAEMSP guidelines for HEMS use [3], these indica-
tions include dozens of situations ranging from tumor-
mediated cord compression needing radiation therapy, to
the need for emergency delivery of an eclamptic, and to
the need for emergency valvuloplasty. The spectrum of
individual non-trau ma patient types that could potentially
benefit from HEMS is daunting in its breadth, but the
task of considering benefits of HEMS in these cases is
worthy of attention for both clinicians and researchers. It
is hoped that the information in this review can inform
and assist those efforts.
[1] C. Moga and C. Harstall, “Air Ambulance Transportation
with Capabilities to Provide Advanced Life Support: IHE
Report to the Ministry of Health,” Institute of Health Eco-
nomics, Calgary, 2007.
[2] S. M. Galvagno Jr., S. Thomas, C. Stephens, E. R. Haut, J.
M. Hirshon, D. Floccare and P. Pronovost, “Helicopter
Emergency Medical Services for Adults with Major
Trauma,” Cochrane Database of Systematic Reviews, Vol.
3, 2013, Article ID: CD009228.
[3] D.P. Thomson, S.H. Thomas, “Guidelines for air medical
dispatch,” Prehospital Emergency Care, Vol. 7, No. 2,
2003, pp. 265-271.
[4] J. Varon, R. Fromm and P. Marik, “Hearts in the Air,”
Chest, Vol. 124, No. 5, 2003, pp. 1636-1637.
[5] R. Kent, L. Newman, R. Johnson and R. Carraway, “Heli-
copter Transport of Ruptured Abdominal Aortic Aneu-
rysms,” Ala Med, Vol. 58, 1989, pp. 13-14.
[6] J. Bruhn, K. Williams and R. Aghababian, “True Costs of
Air Medical vs. Ground Ambulance Systems,” Air Medi-
cal Journal, Vol. 12, No. 8, 1993, pp. 262-268.
[7] D. P. Davis, J. Peay, B. Good, M. J. Sise, F. Kennedy, A.
B. Eastman, T. Velky and D. B. Hoyt, “Air Medical Re-
sponse to Traumatic Brain Injury: A Computer Learning
Algorithm Analysis,” Journal of Trauma, Vol. 64, No. 4,
2008, pp. 889-897.
[8] S. H. Thomas, L. H. Schwamm and M. H. Lev, “Case
Records of the Massachusetts General Hospital. Case
16-2006. A 72-Year-Old Woman Admitted to the Emer-
gency Department Because of a Sudden Change in Men-
tal Status,” New England Journal of Medicine, Vol. 354,
No. 21, 2006, pp. 2263-2271.
[9] N. Hata, N. Kobayashi, T. Imaizumi, S. Yokoyama, T.
Shinada, J. Tanabe, K. Shiiba, Y. Suzuki, H. Matsumoto
and K. Mashiko, “Use of an Air Ambulance System Im-
proves Time to Treatment of Patients with Acute Myo-
cardial Infarction,” Internal Medicine, Vol. 45, No. 2,
2006, pp. 45-50.
[10] T. Imaizumi, N. Hata, N. Kobayashi, S. Yokoyama, T.
Shinada, K. Tokuyama, M. Ishikawa, K. Shiiba, H. Ma-
tsumoto, K. Takuhiro and K. Mashiko, “Early Access to
Patients with Life-Threatening Cardiovascular Disease by
an Air Ambulance Service,” Journal of Nippon Medical
School, Vol. 71, No. 5, 2004, pp. 352-356.
[11] C. Palmer, J. McMullan, W. Knight, M. Gunderman and
W. Hinckley, “Helicopter Scene Response for a STEMI
Patient Transported Directly to the Cardiac Catheteriza-
tion Laboratory,” Air Medical Journal, Vol. 30, No. 6,
2011, pp. 289-292.
[12] S. H. Thomas and A. Arthur, “Helicopter EMS: Research
Endpoints and Potential Benefits,” EM International,
[13] D. J. Floccare, D. F. Stuhlmiller, S. A. Braithwaite, S. H.
Thomas, J. F. Madden, D. G. Hankins, H. Dhindsa and M.
G. Millin, “Appropriate and Safe Utilization of Helicopter
Emergency Medical Services: A Joint Position Statement
with Resource Document,” Prehospital Emergency Care,
Vol. 17, No. 4, 2013, pp. 521-525.
[14] I. Blumen, “A Safety Review and Risk Assessment in Air
Medical Transport,” Air Medical Physician Association,
Salt Lake City, 2002.
[15] K. S. Berns, D. G. Hankins and S. P. Zietlow, “Compari-
son of Air and Ground Transport of Cardiac Patients,” Air
Medical Journal, Vol. 20, No. 6, 2001, pp. 33-36.
Open Access IJCM
Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions 521
[16] M. Phillips, A. O. Arthur, R. Chandwaney, J. Hatfield, B.
Brown, K. Pogue, M. Thomas, M. Lawrence, M. McCar-
roll, M. McDavid and S. H. Thomas, “Helicopter Trans-
port Effectiveness of Patients for Primary Percutaneous
Coronary Intervention,” Air Medical Journal, Vol. 32, No.
3, 2013, pp. 144-152.
[17] B. K. Nallamothu, E. H. Bradley and H. M. Krumholz,
“Time to Treatment in Primary Percutaneous Coronary
Intervention,” New England Journal of Medicine, Vol.
357, 2007, pp. 1631-1638.
[18] J. L. Saver, G. C. Fonarow, E. E. Smith, M. J. Reeves, M.
V. Grau-Sepulveda, W. Pan, D. M. Olson, A. F. Hernan-
dez, E. D. Peterson and L. H. Schwamm, “Time to Treat-
ment with Intravenous Tissue Plasminogen Activator and
Outcome from Acute Ischemic Stroke,” JAMA, Vol. 309,
No. 23, 2013, pp. 2480-2488.
[19] W. M. Konstantopoulos, J. Pliakas, C. Hong, K. Chan, G.
Kim, L. Nentwich and S. H. Thomas, “Helicopter Emer-
gency Medical Services and Stroke Care Regionalization:
Measuring Performance in a Maturing System,” Ameri-
can Journal of Emergency Medicine, Vol. 25, No. 2, 2007,
pp. 158-163.
[20] S. H. Thomas, C. Kociszewski, R. J. Hyde, P. J. Brennan
and S. K. Wedel, “Prehospital Electrocardiogram and
Early Helicopter Dispatch to Expedite Interfacility Trans-
fer for Percutaneous Coronary Intervention,” Critical
Pathways in Cardiology, Vol. 5, No. 3, 2006, pp. 155-
[21] Z. J. Rhinehart, F. X. Guyette, J. L. Sperry, R. M. For-
sythe, A. Murdock, L. H. Alarcon, A. B. Peitzman and M.
R. Rosengart, “The Association between Air Ambulance
Distribution and Trauma Mortality,” Annals of Surgery,
Vol. 257, No. 6, 2013, pp. 1147-1153.
[22] E. Straumann, S. Yoon and B. Naegeli, “Hospital Trans-
fer for Primary Coronary Angioplasty in High Risk Pa-
tients with Acute Myocardial Infarction,” Heart, Vol. 82,
1999, pp. 415-419.
[23] J. Elliott, D. O’Keeffe and R. Freeman, “Helicopter
Transportation of Patients with Obstetric Emergencies in
an Urban Area,” American Journal of Obstetrics & Gy-
necology, Vol. 143, 1982, pp. 157-162.
[24] S. Berge, C. Berg-Utby and E. Skogvoll, “Helicopter
Transport of Sick Neonates: A 14-Year Population-Based
Study,” Acta Anaesthesiologica Scandinavica, Vol. 49,
No. 7, 2005, pp. 999-1003.
[25] A. Tyson, D. Sundberg, D. Sayers, K. Ober and R. Snow,
“Plasma Catecholamine Levels in Patients Transported by
Helicopter for Acute Myocardial Infarction and Unstable
Angina Pectoris,” American Journal of Emergency Medi-
cine, Vol. 6, No. 5, 1988, pp. 435-438.
[26] R. Fromm, D. Taylor, L. Cronin, W. McCallum and R.
Levine, “The Incidence of Pacemaker Dysfunction during
Helicopter Air Medical Transport,” American Journal of
Emergency Medicine, Vol. 10, No. 4, 1992, pp. 333-335.
[27] R. Fromm, E. Hoskins and L. Cronin, “Bleeding Compli-
cations Following Initiation of Thrombolytic Therapy for
Acute Myocardial Infarction: A Comparison of Helicop-
ter-Transported and Nontransported Patients,” Annals of
Emergency Medicine, Vol. 20, No. 8, 1991, pp. 892-895.
[28] M. R. Le May, D. Y. So, R. Dionne, C. A. Glover, M. P.
Froeschl, G. A. Wells, R. F. Davies, H. L. Sherrard, J.
Maloney, J. F. Marquis, E. R. O’Brien, J. Trickett, P.
Poirier, S. C. Ryan, A. Ha, P. G. Joseph and M. Labinaz,
“A Citywide Protocol for Primary PCI in ST-Segment
Elevation Myocardial Infarction,” New England Journal
of Medici ne, Vol. 358, No. 3, 2008, pp. 231-240.
[29] E. Keeley and L. Hills, “Clinical Therapeutics: Primary
PCI for Myocardial Infarction with ST-Segment Eleva-
tion,” New England Journal of Medicine, Vol. 356, No. 1,
2007, pp. 47-52.
[30] C. Grines, D. Westerhausen and L. Grines, “A Random-
ized Trial of Transfer for Primary Angioplasty versus
On-Site Thrombolysis in Patients with High-Risk Myo-
cardial Infarction (Air PAMI Trial),” Journal of the
American College of Cardiology, Vol. 39, No. 11, 2002,
pp. 1713-1719.
[31] D. B. Diercks, M. C. Kontos, J. E. Weber and E. A. Am-
sterdam, “Management of ST-Segment Elevation Myo-
cardial Infarction in EDs,” American Journal of Emer-
gency Medicine, Vol. 26, No. 1, 2008, pp. 91-100.
[32] S. S. Rathore, J. P. Curtis, J. Chen, Y. Wang, B. K. Nal-
lamothu, A. J. Epstein and H. M. Krumholz, “Association
of Door-to-Balloon Time and Mortality in Patients Ad-
mitted to Hospital with ST Elevation Myocardial Infarc-
tion: National Cohort Study,” BMJ, Vol. 338, 2009, p.
[33] D. S. Pinto, A. J. Kirtane, B. K. Nallamothu, S. A. Mur-
phy, D. J. Cohen, R. J. Laham, D. E. Cutlip, E. R. Bates,
P. D. Frederick, D. P. Miller, J. P. Carrozza Jr., E. M.
Antman, C. P. Cannon and C. M. Gibson, “Hospital De-
lays in Reperfusion for ST-Elevation Myocardial Infarc-
tion: Implications When Selecting a Reperfusion Strat-
egy,” Circulation, Vol. 114, No. 19, 2006, pp. 2019-2025.
[34] J. B. Myers, C. M. Slovis, M. Eckstein, J. M. Goodloe, S.
M. Isaacs, J. R. Loflin, C. C. Mechem, N. J. Richmond
and P. E. Pepe, “Evidence-Based Performance Measures
for Emergency Medical Services Systems: A Model for
Expanded EMS Benchmarking,” Prehospital Emergency
Care, Vol. 12, No. 2, 2008, pp. 141-151.
[35] G. De Luca, G. Biondi-Zoccai and P. Marino, “Transfer-
ring Patients with ST-Segment Elevation Myocardial In-
Open Access IJCM
Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions
farction for Mechanical Reperfusion: A Meta-Regression
Analysis of Randomized Trials,” Annals of Emergency
Medicine, Vol. 52, No. 6, 2008, pp. 665-676.
[36] J. C. Blankenship, T. A. Haldis, G. C. Wo od, K. A. Skeld-
ing, T. Scott and F. J. Menapace, “Rapid Triage and T r ans-
port of Patients with ST-Elevation Myocardial Infarction
for Percutaneous Coronary Intervention in a Rural Health
System,” American Journal of Cardiology, Vol. 100, No.
6, 2007, pp. 944-948.
[37] A. P. Reimer, F. M. Hustey and D. Kralovic, “Decreasing
Door-to-Balloon Times via a Streamlined Referral Proto-
col for Patients Requiring Transport,” American Journal
of Emergency Medicine, Vol. 31, No. 3, 2013, pp. 499-
[38] S. Cheskes, L. Turner, R. Foggett, M. Huiskamp, D.
Popov, S. Thomson, G. Sage, R. Watson and R. Verbeek,
“Paramedic Contact to Balloon in Less than 90 Minutes:
A Successful Strategy for ST-Segment Elevation Myocar-
dial Infarction Bypass to Primary Percutaneous Coronary
Intervention in a Canadian Emergency Medical System,”
Prehospital Emergency Care, Vol. 15, No. 4, 2011, pp.
[39] J. T. McMullan, W. Hinckley, J. Bentley, T. Davis, G. J.
Fermann, M. Gunderman, K. W. Hart, W. A. Knight, C. J.
Lindsell, C. Miller, A. Shackleford and W. Brian Gibler,
“Ground Emergency Medical Services Requests for
Helicopter Transfer of ST-Segment Elevation Myocardial
Infarction Patients Decrease Medical Contact to Balloon
Times in Rural and Suburban Settings,” Academic Emer-
gency Medicine, Vol. 19, No. 2, 2012, pp. 153-160.
[40] T. W. Concannon, D. M. Kent, S. L. Normand, J. P.
Newhouse, J. L. Griffith, J. Cohen, J. R. Beshansky, J. B.
Wong, T. Aversano and H. P. Selker, “Comparative Ef-
fectiveness of ST-Segment-Elevation Myocardial Infarc-
tion Regionalization Strategies,” Circulation: Cardiovascu-
lar Quality and Outcomes, Vol. 3, 2010, pp. 506-513.
[41] L. F. Peterson and L. R. Peterson, “The Safety of Perfor-
ming Diagnostic Cardiac Catheterizations in a Mobile Ca-
theterization Laboratory at Primary Care Hospitals,” An-
giology, Vol. 55, No. 5, 2004, pp. 499-506.
[42] A. D. Frutkin, S. K. Mehta, T. Patel, P. Menon, D. M.
Safley, J. House, C. W. Barth Ⅲ, J. A. Grantha m and S. P.
Marso, “Outcomes of 1,090 Consecutive, Elective, Non-
selected Percutaneous Coronary Interventions at a Com-
munity Hospital without Onsite Cardiac Surgery,” Ameri-
can Journal of Cardiology, Vol. 101, No. 1, 2008, pp. 53-
[43] W. J. Cantor, D. Fitchett, B. Borgundvaag, J. Ducas, M.
Heffernan, E. A. Cohen, L. J. Morrison, A. Langer, V.
Dzavik, S. R. Mehta, C. Lazzam, B. Schwartz, A. Casa-
nova, S. G. Goodman and T.-A.T. Investigators, “Routine
Early Angioplasty after Fibrinolysis for Acute Myocardial
Infarction,” The New England Journal of Medicine, Vol.
360, No. 26, 2009, pp. 2705-2718.
[44] G. Lindbeck, D. Groopman and R. Powers, “Aeromedical
Evacuation of Rural Victims of Nontraumatic Cardiac
Arrest,” Annals of Emergency Medicine, Vol. 22, No. 8,
1993, pp. 1258-1262.
[45] H. Werman, R. Falcone, S. Shaner, H. Herron, R. John-
son, P. Lacey, S. Childress and G. Kampman “Helicopter
Transport of Patients to Tertiary Care Centers after Car-
diac Arrest,” The American Journal of Emergency Medi-
cine, Vol. 17, No. 2, 1999, pp. 130-134.
[46] J. L. Saver, “Time Is Brain--Quantified,” Stroke, Vol. 37,
No. 1, 2006, pp. 263-266.
[47] J. A. Chalela, S. E. Kasner, E. C. Jauch and A. M. Pancioli,
“Safety of Air Medical Transportation after Tissue Plasmi-
nogen Activat or Ad minist ration in Acute Ischemic S tr ok e ,”
Stroke, Vol. 30, No. 11, 1999, pp. 2366-2368.
[48] M. B. Conroy, S. U. Rodriguez, S. E. Kimmel and S. E.
Kasner, “Helicopter Transfer Offers Benefit to Patients
with Acute Stroke,” Stroke, Vol. 30, 1999, pp. 2580-2584.
[49] K. R. Lees, E. Bluhmki, R. von Kummer, T. G. Brott, D.
Toni, J. C. Grotta, G. W. Albers, M. Kaste, J. R. Marler,
S. A. Hamilton, B. C. Tilley, S. M. Davis, G. A. Donnan,
W. Hacke, A. N. Ecass, E.r.-P.S. Group, K. Allen, J. Mau,
D. Meier, G. del Zoppo, D. A. De Silva, K. S. Butcher, M.
W. Parsons, P. A. Barber, C. Levi, C. Bladin and G.
Byrnes, “Time to Treatment with Intravenous Alteplase
and Outcome in Stroke: An Updated Pooled Analysis of
Lancet, Vol. 375, No. 9727, 2010, pp. 1695-1703.
[50] J. Svenson, J. O’Connor and M. Lindsay, “Is Air Trans-
port Faster? A Comparison of Air Versus Ground Trans-
port Times for Interfacility Transfers in a Regional Re-
ferral System,” Air Medical Journal, Vol. 25, No. 4, 2006,
pp. 170-172.
[51] T. J. Crocco, J. C. Grotta, E. C. Jauch, S. E. Kasner, R. U.
Kothari, B. R. Larmon, J. L. Saver, M. R. Sayre and S. M.
Davis, “EMS Management of Acute Stroke—Prehospital
Triage (Resource Document to NAEMSP Position State-
ment),” Prehospital Emergency Care, Vol. 11, No. 3, 2007,
pp. 313-317.
[52] L. H. Schwamm, A. Pancioli, J. E. Acker, L. B. Gold-
stein, R. D. Zorowitz, T. J. Shephard, P. Moyer, M. Gor-
man, S. C. Johnston, P. W. Duncan, P. Gorelick, J. Frank,
S. K. Stranne, R. Smith, W. Federspiel, K. B. Horton, E.
Magnis and R. J. Adams, “Recommendations for Estab-
lishment of Stroke Systems of Care: Recommendations
from the American Stroke Association’s Ta sk F o rc e o n t h e
Development of Stroke Systems,” Stroke, Vol. 36, No. 3,
2005, pp. 690-703.
[53] V. Reiner-Deitemyer, Y. Teuschl, K. Matz, M. Reiter, R.
Eckhardt, L. Seyfang, C. Tatschl and M. Brainin, “Heli-
copter transport of Stroke Patients and Its Influence on
Thrombolysis Rates: Data from the Austrian Stroke Unit
Registry,” Stroke, Vol. 42, No. 5, 2011, pp. 1295-1300.
Open Access IJCM
Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions 523
[54] S. L. Silliman, B. Quinn, V. Huggett and J. G. Merino,
“Use of a Field-to-Stroke Center Helicopter Transport
Program to Extend Thrombolytic Therapy to Rural Resi-
dents,” Stroke, Vol. 34, No. 3, 2003, pp. 729-733.
[55] R. Lambert, S. Cabardis, J. Valance, E. Borge, J. L. Du-
casse and J. J. Arza lier, “ Fibrinolysis and Acute Stroke in
Maritime Search and Rescue Medical Evacuation,” An-
nales Françaises dAnesthésie et de Réanimation, Vol. 27,
No. 3, 2008, pp. 249-251.
[56] Y. Nakagawa, S. Morita, K. Akieda, M. Nagayama, I.
Yamamoto, S. Inokuchi, S. Oda and M. Matsumae, “Cri-
tical role of the Doctor-Heli System on Cerebral Infarc-
tion in the Superacute Stage—Report of an Outstanding
Pilot Case,” Tokai Journal of Experimental and Clinical
Medicine, Vol. 30, No. 2, 2005, pp. 123-126.
[57] L. Candelise, M. Gattinoni, A. Bersano, G. Micieli, R.
Sterzi and A. Morabito, “Stroke-Unit Care for Acute Stroke
Patients: An Observational Follow-Up Study ,” Lancet, Vol.
369, No. 9558, 2007, pp. 299-305.
[58] K. C. Albright, C. C. Branas, B. C. Meyer, D. E. Matherne-
Meyer, J. A. Zivin, P. D. Lyden and B. G. Carr, “ACCESS:
Acute Cerebrovascular Care In Emergency Stroke Sys-
tems,” JAMA Neurology, Vol. 67, No. 10, 2010, pp. 1210-
[59] M. D. Olso n and A. A. Rabin st ein, “D oe s Hel ico pte r Emer-
gency Medical Service Transfer Offer Benefit to Patients
with Stroke?” Stroke, Vol. 43, No. 3, 2012, pp. 878-880.
[60] B. P. Walcott, J. V. Coumans, M. K. Mian, B. V. Nahed and
K. T. Kahle, “Interfacility Helicopter Ambulance Transport
of Neurosurgical Patients: Observations, Utilization, and
Outcomes from a Quaternary Care Hospital,” PLoS ONE,
Vol. 6, No. 10, 2011, Article ID: e26216.
[61] R. Silbergleit, P. Scott, M. Lowell and R. Silbergleit,
“Cost-Effectiveness of Helicopter Transport of Stroke Pa-
tients for Thrombolysis,” Academic Emergency Medicine,
Vol. 10, No. 9, 2003, pp. 966-972.
[62] E. C. Leira, A. Ahmed, D. L. Lamb, H. M. Olalde, R. C.
Callison, J. C. Torner and H. P. Adams Jr., “Extending Acu-
te Trials to Remote Populations: A Pilot Study During In-
terhospital Helicopter Transfer,” Stroke, Vol. 40, No. 3,
2009, pp. 895-901.
[63] S. Shewakramani, S. H. Thomas, T. H. Harrison and J. D.
Gates, “Air Transport of Patients with Unstable Aortic
Aneurysms Directly into Operating Rooms,” Prehospital
Emergency Care, Vol. 11, No. 3, 2007, pp. 337-342.
[64] C. H. Pieper, J. Smith, G. F. Kirsten and P. Malan, “The
Transport of Neonates to an Intensive Care Unit,” South
African Medical Journal, Vol. 84, Suppl. 11, 1994, pp.
[65] K. Hon, H. Olsen, B. Totapally and T. Leung, “Air Verus
Ground Transportation of Artificially Ventilated Neona-
tes: Comparative Differences in Selected Cardiopulmon-
ary Parameters,” Pediatric Emergency Care, Vol. 22, No.
2, 2006, pp. 107-112.
[66] M. Gausche-Hill, R. J. Lewis, S. J. Stratton, B. E. Haynes,
C. S. Gunter, S. M. Goodrich, P. D. Poore, M. D.
McCollough, D. P. Henderson, F. D. Pratt and J. S. Seidel,
“Effect of out-of-Hospital Pediatric Endotracheal Intuba-
tion on Survival and Neurological Outcome: A Controlled
Clinical Trial,” JAMA, Vol. 283, No. 6, 2000, pp. 783-
[67] W. W. Tollefsen, C. A. Brown , K. L. Cox and R. M.
Walls, “Two Hundred Sixty Pediatric Emergency Airway
Encounters by Air Transport Personnel: A Report of the
Air Transport Emergency Airway Management (NEAR
VI: ‘A-TEAM’) Project,” Pediatric Emergency Care, Vol.
29, No. 9, 2013, pp. 963-968.
[68] T. H. Harrison, S. H. Thomas and S. K. Wedel, “Success
rates of Pediatric Intubation by a Non-Physician-Staffed
Critical Care Transport Service,” Pediatric Emergency
Care, Vol. 20, No. 2, 2004, pp. 101-107.
[69] W. W. Tollefsen, J. Chapman, M. Frakes, M. Gallagher,
M. Shear and S. H. Thomas, “Endotracheal Tube Cuff
Pressures in Pediatric Patients Intubated before Aerome-
dical Transport,” Pediatric Emergency Care, Vol. 26, No.
5, 2010, pp. 361-363.
[70] J. Orf, S. H. Thomas, W. Ahmed, L. Wiebe, P. Chamber-
lin, S. K. Wedel and C. Houck, “Appropriateness of En-
dotracheal Tube Size and Insertion Depth in Children Un-
dergoing Air Medical Transport,” Pediatric Emergency
Care, Vol. 16, No. 5, 2000, pp. 321-327.
[71] J. W. van Hook, T. G. Leicht, C. L. van Hook, P. L. Dick,
G. D. Hankins and C. J. Harvey, “Aeromedical Transfer of
Preterm Labor Patients,” Texas Medicine, Vol. 94, No. 11,
1998, pp. 88-90.
[72] M. Ohara, Y. Shimizu, H. Satoh, T. Kasai, S. Takano, R.
Fujiwara, Y. Furusawa, S. Kameda, T. Matsumura, H.
Narimatsu, E. Kusumi, Y. Kodama, M. Kami, N. Mura-
shige and M. Suzuki, “Safety and Usefulness of Emer-
-gency Maternal Transport Using Helicopter,” Journal of
Obstetrics and Gynaecology Research, Vol. 34, No. 2,
2008, pp. 189-194.
[73] J. A. Russell, “Management of Sepsis,” The New England
Journal of Medicine, Vol. 355, No. 16, 2006, pp. 1699-
[74] D. Reily, E. Tollok, K. Mallitz, C. W. Hanson III and B.
D. Fuchs, “Successful Aeromedical Transport Using In-
haled Prostacyclin for a Patient with life-Threatening Hy-
poxemia,” Chest, Vol. 125, No. 4, 2004, pp. 1579-1581.
[75] E. Vu, R. Wand and R. Schlamp, “Facilitated Delivery of
Antidotes by the British Columbia Air Ambulance Ser-
vice during Secondary Aeromedical Transport in Poisoned
or Toxic Patients,” Prehospital Emergency Care, Vol. 11,
2007, p. 135.
[76] S. Thomas, T. Judge, M. J. Lowell, R. D. MacDonald, J.
Open Access IJCM
Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions
Open Access IJCM
Madden, K. Pickett, H. A. Werman, M. L. Shear, P. Patel,
G. Starr, M. Chesney, R. Domeier, P. Frantz, D. Funk and
R. D. Greenberg, “Airway Management Success and Hy-
poxemia Rates in Air and Ground Critical Care Transport:
A Prospective Multicenter Study,” Prehospital Emergency
Care, Vol. 14 , No. 3, 2010 , pp. 283- 291.
[77] S. H. Thomas, J. Orf, S. K. Wedel and A. K. Conn, “Hy-
perventilation in Traumatic Brain Injury Patients: Incon-
sistency between Consensus Guidelines and Clinical
Practice,” Journal of Trauma-Injury Infection & Critical
Care, Vol. 52, No. 1, 2002, pp. 47-52.
[78] S. Thomas, “Hyperventilation in Patients with Traumatic
Brain Injury: Lessons for the Acute Care Provider,” Salud
CienciaJournal of the Sociedad Iberoamericana de In-
formación Científica, Vol. 12, 2004, pp. 22-26.
[79] D. Davis, J. Ster n, M. Ochs and D. B. Hoy t, “A Follow-U p
Anal ys is of Factors Associated with Head-Injury Mortality
after Paramedic Rapid Sequence Intubation,” Journal of
Trauma-Injury Infection & Critical Care, Vol. 59, No. 2,
2005, pp. 486-490.
[80] D. Davis, J. Dunford, M. Ochs, R. Heister, D. Hoyt, M.
Ochs and J. V. Dunford, “Ventilation Patterns Following
Paramedic Rapid Sequence Intubation of Patients with Se-
vere Traumatic Brain I njury,” Neurocritical Care, Vol. 2,
No. 2, 2005, pp. 165-171.
[81] D. P. Davis, J. V. Dunford, J. C. Poste, M. Ochs, T. Hol-
brook and D. Fortlage, M. J. Size, F. Kennedy and D. B.
Hoyt, “The Impact of Hypoxia and Hyperventilation on
Outcome Following Paramedic Rapid Sequence Intuba-
tion of Patients with Severe Traumatic Brain Injury,”
Journal of Trauma-Injury Infection & Critical Care, Vol.
57, No. 1, 2004, pp. 1-10.
[82] M. Helm, R. Schuster, J. Hauke and L. Lampl, “Tight
Control of Prehospital Ventilation by Capnography in
Major Trauma Victims,” British Journal of Anesthesia,
Vol. 90, No. 3, 2003, pp. 327-332.
[83] B. J. Zink and R. F. Maio, “Out-of-Hospital Endotracheal
Intubation in Traumatic Brain Injury: Outcomes Research
Provides us with an Unexpected Outcome,” Annals of
Emergency Medicine, Vol. 44, No. 5, 2004, pp. 451-453.
[84] G. Berlot, C. La Fata, B. Bacer, B. Biancardi, M. Viviani,
U. Lucangelo, P. Gobbato, L. Torelli, E. Carchietti, G.
Trillo, M. Daniele and A. Rinaldi, “Influence of Prehos-
pital Treatment on the Outcome of Patients with Severe
Blunt Traumatic Brain Injury: A Single-Centre Study,”
European Journal of Emergency Medicine, Vol. 16, No. 6,
2009, pp. 312-317.
[85] M. A. Turturro, “Pain, Priorities, and Prehospital Care,”
Prehospital Emergency Care, Vol. 6, No. 4, 2002, pp.
[86] C. McEachin, J. McDermott and R. Swor, “Few EMS Pa-
tients with Lower-Extremity Fractures Receive Prehospi-
tal Analgesia,” Prehospital Emergency Care, Vol. 6, No.
4, 2002, pp. 406-410.
[87] R. Swor, C. M. McEachin, D. Seguin and K. H. Grall,
“Prehospital Pain Management in Children Suffering
Traumatic Injury,” Prehospital Emergency Care, Vol. 9,
No. 1, 2005, pp. 40-43.
[88] S. H. Thomas and S. Shewakramani, “Prehospital Trauma
Analgesia,” The Journal of Emergency Medicine, Vol. 35,
No. 1, 2008, pp. 47-57.