HEMS vs GEMS discusses the differences between helicopter emergency medical services (HEMS) and ground emergency medical services (GEMS) for transporting trauma patients. Patients transported by HEMS tend to be more severely injured and HEMS is able to complete more advanced prehospital procedures. However, HEMS also has longer on-scene and transport times. The evidence on whether HEMS improves survival rates compared to GEMS is inconclusive, with some studies finding a benefit and others not. Overall, the presentation examines the tradeoffs between HEMS and GEMS across factors like speed, patient severity, prehospital treatment capabilities, and survival outcomes.

1. HEMS vsGEMS
by ground or by air: which is the best
way to take care of traumatized
patients
Narrative review by
Mario Rugna
Physician
GEMS and HEMS
Florence, Italy
Visit MEDEST
www.medest118.com

2. References
 On line literature search
 You can find the original articles mentioned in the
presentation at:
http://1drv.ms/1GtLgLW

3. Cost-Effectivness
Cost-Effectiveness of Helicopter Versus Ground Emergency Medical
Services for Trauma Scene Transport in the United States
M. Kit Delgado, MD, Kristan L. Staudenmayer, MD, N. Ewen Wang
Ann Emerg Med. 2013 October ; 62(4): 351–364.e19.
 Conclusions
 Compared to ground EMS transport, helicopter scene
transport is cost-effective if it results in a reduction in
the relative risk of death for seriously injured trauma
patients of at least 17% given our model assumptions.
This translates into the need to save at least 1.6 lives
per 100 patients transported with serious injury. Given
current uncertainties, helicopter EMS
 Given current evidence, it is not clear that HEMS
achieves this mortality or disability reduction.
 Reducing over-triage of minor injury patients to HEMS
would improve its cost-effectiveness.

4. Benefit of
HEMS
Galvagno Critical Care 2013, 17:169

5. Speed
HEMS mission
 Time to reach the target
 On scene time
 Transport time toTrauma Center

6. Speed
HEMS to target
 Dispatch
 Take off
 Landing
 On the target
 Nearby area/rendez-vous with ground EMS
 No safe landing space (Winch, hovering )
Dispatch Take-off Landing

7. Speed
Time to reach the target
HEMS vs GEMS
Marco A. Diaz, et al. JTrauma. 2005;58:148–153.

8. Speed
On scene time
Survival benefit of helicopter emergency medical services compared to ground
emergency medical services in traumatized patients
Andruszkow et al. Critical Care 2013, 17:R124
 The extent of medical treatment on-scene which involved
intubation, chest and treatment with vasopressors was
more extensive in HEMS (p<0.001) resulting in prolonged
on-scene time (39.5 62 vs. 28.9 minutes, p<0.001).
Impact of prehospital mode of transport after severe injury: A multicenter evaluation
from the Resuscitation Outcomes Consortium
Eileen M. Bulger, Danielle Guffey. JTrauma Acute Care Surg. 2012 March ; 72(3): 567–803
 Patients transported by air had higher rates of prehospital
intubation (81% vs. 36%;) received more intravenous fluids
(mean 1.3 L vs. 0.8 L; p< 0.001), and had longer prehospital
times (mean 76.1 minutes vs. 43.5 minutes; p<0.001).

9. Speed
When Is the Helicopter Faster? A Comparison of Helicopter
and Ground AmbulanceTransportTimes
Marco A. Diaz, Gregory W. Hendey, and Herbert G. Bivins, JTrauma. 2005;58:148 –153.
Time from 911 call to hospital
arrival versus distance from
hospital, for ground, non
simultaneously dispatched
(NSD), and simultaneously
dispatched (SD) helicopter
transports. Each bar rep-
resents the mean time from
911 call to hospital arrival, in
minutes, with 95% confidence
intervals.

10. Speed
When Is the Helicopter Faster? A Comparison of Helicopter and Ground Ambulance
TransportTimes
Marco A. Diaz, Gregory W. JTrauma. 2005;58:148 –153.
Results:
 Ground trans-ports were significantly faster than non
simultaneously dispatched ( NSD) helicopter transports
at distances under 20 miles. Between 20 and 44 miles,
there was no significant difference, and at distances
greater than 45 miles, NSD helicopter transport was
significantly faster than ground transport
 Simultaneously dispatched (SD) helicopter
transports became significantly faster than ground
transport at distances greater than 10miles from the
hospital.

11. Speed
When Is the Helicopter Faster? A Comparison of Helicopter and Ground Ambulance
TransportTimes
Marco A. Diaz, Gregory W. JTrauma. 2005;58:148 –153.
Conclusions:
 Ground ambulance transport provided the shortest
911-hospi-tal arrival interval at distances less than 10
miles from the hospital. At distances greater than 10
miles, simultaneously dispatched air transport was
faster.
 Non simultaneous dispatched helicopter transport
was faster than ground if greater than 45 miles from
the hospital.

12. Severity
Dennis Den Hartog et al. Injury, Int. J. Care Injured (2015)
 Patients in the HEMS group were more severely
injured (ISS 26 versus 22; p < 0.001) and had more
disturbed vital parameters (lower GCS and RTS; p <
0.001).
Andruszkow et al. CriticalCare 2013, 17:R124
 Patients treated by HEMS were more seriously
injured compared to GEMS (ISS 26.0 vs. 23.7, P <
0.001) with more severe chest and abdominal injuries.
Bulger et al.JTrauma Acute Care Surg 2012 March
 Patients transported by air were more severely
injured (mean Injury Severity Score, 30.3 vs. 22.8;
p<0.001)

13. Severity
HelicopterSceneTransport ofTrauma Patients with NonlifeThreatening Injuries: A Meta-
Analysis
Bryan E. Bledsoe, DO, FACEP, A. KeithWesley, MD, FACEP, Marc Eckstein, MD, FACEP,Thomas M.
Dunn, PhD, Michael F. O’Keefe, MS JTrauma. 2006;60:1257–1266.
Results:
 There were 22 studies comprising 37,350 patients that met the inclusion
criteria.
 According to the ISS, 60.0% [99% confidence interval (CI): 54.5–64.8] of
patients had minor injuries,
 According to theTS, 61.4% (99%CI: 60.8–62.0) of pa-tients had minor injuries.
 According toTRISS methodology, 69.3% (99% CI: 58.5– 80.2) of patients had a
greater than 90% chance of survival and thus nonlife threatening injuries.
 There were 25.8% (99% CI: 1.0–52.6) of patients discharged within 24 hours
after arrival at the trauma center.
Conclusions:
 The majority of trauma patients transported from the scene by helicopter
have nonlife-threatening injuries.
 Efforts to more accurately identify those patients who would benefit most
from helicopter transport from the accident scene to the trauma center are
needed to reduce helicopter overutilization.

14. Trauma
Center
Access
Survival benefit of helicopter emergency medical services
compared to ground emergency medical services in traumatized
patients
Andruszkow et al. Critical Care 2013, 17:R124
 HEMS patients were more often transported to level
I trauma centers compared to GEMS (HEMS: 90.1%
vs. GEMS: 75.9%). Accordingly, GEMS transported their
patients more frequently to level II (HEMS: 9.9% vs.
GEMS: 24.1%).

15. Crew
Impact of prehospital mode of transport after severe injury:
A multicenter evaluation from the Resuscitation Outcomes
Consortium
Eileen M. Bulger, Danielle Guffey. JTrauma Acute Care Surg.
2012 March ; 72(3): 567–803
Results
 Patients transported by air had higher rates of
prehospital intubation (81% vs. 36%; p < 0.001),
received more intravenous fluids (mean 1.3 L vs.
0.8 L; p < 0.001), and had longer prehospital
times (mean 76.1 minutes vs. 43.5 minutes;
p<0.001).
Conclusions
 However, air medical transported more severely
injured patients with more advanced life support
procedures and longer prehospital time.

16. Crew
Survival benefit of helicopter emergency medical services
compared to ground emergency medical services in traumatized
patients
Andruszkow et al. Critical Care 2013, 17:R124
Methods:
 Traumatized patients (Injury Severity Score; ISS ≥9)
primarily treated by HEMS or ground emergency
medical services (GEMS) between 2007 and 2009 were
analyzed using theTraumaRegister DGU® of the
German Society forTrauma Surgery.

17. Crew
Survival benefit of helicopter emergency medical services compared to ground
emergency medical services in traumatized patients Andruszkow et al. Critical Care
2013, 17:R124
Results:
 More preclinical interventions were found in HEMS
transported patients.

18. Crew
Survival benefit of helicopter emergency medical services compared to ground
emergency medical services in traumatized patients Andruszkow et al. Critical Care
2013, 17:R124
Results:
 Sensitivity and specificity of preclinical diagnoses were
not superior in HEMS compared to GEMS.

19. Survival
Helicopter emergency medical services for adults with major
trauma (Review 2013)
GalvagnoJr SM,Thomas S, Stephens C, Haut ER, Hirshon JM, Floccare
D, Pronovost P
Author Conclusions
 An accurate composite estimate of the benefit of
HEMS could not be determined.
 Although five of the nine multivariate regression
studies indicated improved survival associated with
HEMS, the remainder did not.
 All were subject to a low quality of evidence as
assessed by the GRADEWorking Group criteria due to
their non-randomized design.

20. Survival
Survival benefit of helicopter emergency medical
services compared to ground emergency medical
services in traumatized patients Andruszkow et al.
Critical Care 2013, 17:R124
Conclusions:
 Transportation by HEMS resulted in a significant
survival benefit compared to GEMS patients despite
increased injury severity and incidence of posttrau-
matic complications (MODS, sepsis).

21. Survival
Survival benefit of physician-staffed Helicopter
Emergency Medical Services (HEMS) assistance for
severely injured patients
Dennis Den Hartog,et al. Injury, Int. J. Care Injured (2015)
Conclusions:
The present study indicates an additional 5.33 lives
saved per 100 dispatches of the physician-staffed
HEMS. Given the excellent statistical power of this
study (>90%), physician-staffed HEMS is confirmed to
be an evidence-based valuable addition to the EMS
systems in saving lives of severely injured patients.

22. Bottom line
Speed
MissionTime
 In case of simultaneous activation HEMS is competitive
for distance >10 miles
 In case of non simultaneous activation HEMS is faster
for distances >45 miles fromTraumaCenter
On scene time
 HEMS > GEMS

23. Bottom line
Severity
 HEMS patients are generally more severely injured
than GEMS patients
Trauma Center Access
 HEMS transported patients have more chances to be
referred to a level ITraumaCenter

24. Bottom line
Crew
 More time on scene (beyond the golden hour)
 More procedures performed
 The accuracy of prehospital documented diagnoses
was not increased in HEMS compared to GEMS rescue

25. Bottom line
Survival
 No definitive evidences on HEMS benefits on survival
rate
 Recent literature points on a trend toward an increased
chances of survival in some categories of trauma
patients transported by HEMS

26. Safety
1
6
12 12
19
0
2
4
6
8
10
12
14
16
18
20
Airline
Commuter
Ground Ambulance
All Helicopters
Medical Helicopters
Fatal crashes per million of flight
Source: AMPA, A Safety Review and Risk Assessment in
Air MedicalTransport (2002)