The Science Behind Trauma Care
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Transcript The Science Behind Trauma Care
The Science Behind
Trauma Care
Dr. Bryan E. Bledsoe
Professor, Emergency Medicine
The George Washington University Medical
Center
Audience Interaction
Which of the following actresses is my
favorite?
A. Sandra Bullock
B. Angelina Jolie
C. Salma Hayek
D. Nicole Kidman
E. George Michael
Science in Trauma Care
Positive
Evidence
Negative
Evidence
No Evidence
Or
Equivocal Evidence
Levels of Evidence
Not all scientific
evidence is the same.
Audience Interaction
My ambulance service practices
evidence-based prehospital care?
A. Strongly agree
B. Agree
C. Neither agree nor disagree
D. Disagree
E. Strongly disagree.
Levels of Evidence
Center for Evidence-Based Medicine
(Oxford)
Ia. Meta-analysis of RCTs
Ib. One RCT.
IIa. Controlled trial without randomisation.
IIb. One other type of quasi-experimental study.
III. Descriptive studies, such as comparative studies,
correlation studies, and case-control studies.
IV. Expert committee reports or opinions, or clinical
experience of respected authorities or both.
Levels of Evidence
American Heart Association
1. Positive randomized controlled trials.
2. Neutral randomized controlled trials.
3. Prospective, non-randomized controlled trials.
4. Retrospective, non-randomized controlled trials
5. Case series (no control group)
6. Animal studies
7. Extrapolations
8. Rational conjecture (common sense)
Levels of Evidence
Levels of Evidence
The closer a study adheres to the
scientific method, the more valid the
study.
The more valid the study, the closer it is
to the truth.
Ranking the Evidence
Class I:
Derived from the strongest studies of
therapeutic interventions (RCTs) in humans.
Used to support treatment
recommendations of the highest order called
practice standards.
Ranking the Evidence
Class II:
Derived from the comparative studies with
less strength (nonrandomized cohort
studies, RCTs with significant design flaws,
and case-control studies).
Used to support recommendations called
guidelines.
Ranking the Evidence
Class III:
Derived from the other sources of
information, including case series and expert
opinion.
Used to support practice options.
Ranking the Evidence
Overall term for all of
the recommendations
is practice parameters.
EMS Practice Changes
EMS Practices refuted by empiric
evidence:
Critical Incident Stress Management (CISM)
MAST/PASG
Trendelenburg Position
High-Volume Fluid Resuscitation
EMS Practice Changes
EMS Practices unsupported by empiric
evidence:
Medical Priority Dispatch
System Status Management
High-Dose Epinephrine
High-Dose Steroids for Acute Spinal Cord
Injury
Intraosseous Needles
CPR Compression Vest
EMS Practice Changes
EMS Practice changes based upon
empiric evidence:
AED usage (first 6-8 minutes)
CPR
Field death pronouncement in blunt
traumatic cardiac arrest.
EMS Practice Changes
EMS Practices at risk for change because
of empiric evidence:
Pediatric Endotracheal Intubation
Rapid Sequence Intubation (RSI) in
Traumatic Brain Injury (TBI)
Endotracheal Intubation in TBI
Guiding Prehospital Care
1. There should be a link between the
2.
available evidence and treatment
recommendations.
Empirical evidence should take
precedence over expert judgement in
the development of guidelines.
Guiding Prehospital Care
“In science, there are
no authorities.”
Carl Sagan, PhD
1934-1996
Guiding Prehospital Care
3. The available research should be
searched using appropriate and
comprehensive search terminology.
4. A thorough review of the scientific
literature should precede guideline
development.
Guiding Prehospital Care
5. The evidence should be evaluated and
weighted, depending upon the scientific
validity of the method used to generate
the evidence.
6. The strength of the evidence should be
reflected in the strength of the
recommendations reflecting scientific
certainty (or the lack thereof).
Guiding Prehospital Care
7. Expert judgement should be used to
evaluate the quality of the literature and
to formulate guidelines when the
evidence is weak or nonexistent.
8. Guideline development should be a
multidisciplinary process, involving key
groups affected by the recommendations.
Audience Interaction
In regard to the OPALS study:
A. I follow the OPALS study regularly.
B. I have read some of the OPALS study
papers.
C. I have heard of the OPALS study but not
seen any results.
D. What is the OPALS study?
E. None of the above applies.
Empiric Research in EMS
Phase I: Determined baseline survival rate for each study
community (36 months) prior to Phase II.
Phase II: Assessed the survival for 12 months after the
introduction of rapid defibrillation and demonstrated that
relatively inexpensive community rapid defibrillation
programs increase survival for cardiac arrest patients
(n=5,000+ patients).
Phase III: Assessed survival outcomes months after the
introduction of full ALS programs for 36 months for cardiac
arrest patients and major trauma patients, and for 6
months for respiratory distress patients.
Empiric Research in EMS
Phase I: Survival improved with:
• Decreasing EMS response intervals
• Bystander-CPR
• First responder CPR by fire or police
Phase II: Survival improved with:
• Rapid defibrillation (survival increased from 3.9% to
5.2%) resulted in 33% improvement in survival
• An additional 21 lives saved each year
• Increased survival was also associated with bystander
and first responder CPR.
Empiric Research in EMS
Phase III:
Cardiac Arrest:
• The addition of advanced-life-support interventions
did not improve the rate of survival after out-ofhospital cardiac arrest in a previously optimized
emergency-medical-services system of rapid
defibrillation.
• 8-minute response time too long.
Empiric Research in EMS
Phase III:
Cardiac Arrest:
• Most cardiac arrests occur in private locations
(84.7%) compared to public places (15.3%).
Communities should review locations of their
cardiac arrests when designing CPR training and
public access defibrillation programs.
Empiric Research in EMS
Phase III:
Cardiac Arrest:
• Among ALS interventions, intubation, atropine and
epinephrine had a negative association and only
lidocaine had a positive association with survival.
• Pediatric cardiac arrests are most often due to
respiratory arrests or trauma, SIDS, trauma and
drowning.
• Citizen-initiated CPR is strongly and independently
associated with better quality of life.
Empiric Research in EMS
Phase III:
Chest Pain:
• Clearly showed important benefit from ALS programs
for mortality and other outcomes.
Empiric Research in EMS
Phase III:
Respiratory Distress:
• After adjustment for demographic, clinical, and EMS
factors, the only interventions associated with better
survival were salbutamol and NTG.
• Most children are not severely ill, most do not receive
ALS interventions, there is a high rate of non-transport,
and the vast majority are discharged home from the
ED.
Empiric Research in EMS
Phase III:
Pediatric Care:
• The majority of patients did not require immediate or
urgent medical care and had good short-term
outcomes.
Science in Trauma Care
Practices with strong positive evidence:
Access to trauma centers
Specialized care (pediatrics, burns, spinal
cord injury)
Science in Trauma Care
Practices with positive evidence:
Permissive hypotension
Splinting
Pain management
Head injury management
Hemoglobin-Based Oxygen Carrying
Solutions (HBOCs)
Science in Trauma Care
Practices with no evidence or equivocal
evidence:
The “Golden Hour”
Medical helicopters
Trendelenburg position
Traction splints
Rapid sequence intubation (RSI) in traumatic
brain injury (TBI)
Science in Trauma Care
Practices with negative evidence:
MAST/PASG
Steroids for acute SCI
High-volume fluid therapy
Prehospital intubation in traumatic brain
injury
Pediatric endotracheal intubation
Audience Participation
In regard to current prehospital practice in my
system, which of the following best describes
trauma care?
A. We still used MAST/PASG and administer large
volumes of fluid to restore normal BP.
B. We do not use the MAST/PASG but administer
large volumes of fluid to restore BP.
C. We administer enough fluid to maintain a blood
pressure >100 mm Hg.
D. We administer enough fluid to maintain a blood
pressure > 90 mm Hg.
E. We administer enough fluid to maintain a blood
pressure > 80 mm Hg.
Science in Trauma Care
Practices with strong negative evidence:
Scene stabilization
Changes in US Trauma Practice
IV Fluid Restriction
Permissive Hypotension
Hemoglobin-Based Oxygen Carrying
Solutions (HBOCs)
Less Aggressive Airway Management
Helicopter Overutilization
IV Fluid Restriction
Should prehospital
personnel administer
large volumes of IV fluids
rapidly to trauma victims
or delay fluid
resuscitation until
hospital arrival?
IV Fluid Restriction
Traditional approach
to trauma patient
with hypotension
was 2 large bore IVs
and wide open
crystalloid
administration.
IV Fluid Restriction
Recommendation
has been to replace
lost blood with
isotonic crystalloids
at a 3:1 ratio
(IVF:blood loss)
IV Fluid Restriction
High volume IV fluid
administration was
based on several
animal studies from
the 1950s and 1960s.
IV Fluid Restriction
High volume IV fluid
treatment was used
in Viet Nam and
transferred to US and
western civilian
prehospital care
practices.
IV Fluid Restriction
Several animal studies in
the 1980s and 1990s
found that treatment with
IV fluids before
hemorrhage was
controlled increased the
mortality rate, especially
if the BP was elevated.
IV Fluid Restriction
Raising the BP and restoring perfusion to
vital organs are clearly believed to be
beneficial after hemorrhage is controlled.
Growing evidence indicates that raising it
before achieving adequate hemostasis
may be detrimental.
IV Fluid Restriction
Administering large quantities of IV fluids
without controlling the hemorrhage results in:
hemodilution with decreased hematocrit
decreased available hemoglobin (and oxygencarrying capacity)
decreased clotting factors.
This effect is found regardless of the fluid used
(blood, LR, NS, hypertonic saline).
IV Fluid Restriction
Bickell WH, Wall MJ Jr, Pepe PE, et al. Immediate
versus delayed fluid resuscitation for hypotensive
patients with penetrating torso injuries. N Eng J Med.
1994;331:1105-9
598 patients with penetrating torso injury and systolic
BP ≤ 90 mmHg in prehospital setting.
Randomized to receive standard high-volume fluids or
fluids delayed until patient in OR.
IV Fluid Restriction
Results:
Group Divisions
Delayed: n=289
Standard fluids: n=309
Survival:
Delayed: 70%
Standard fluids: 62%
Complications:
Delayed: 23%
Standard fluids: 30%
IV Fluid Restriction
CONCLUSIONS: For hypotensive patients
with penetrating torso injuries, delay of
aggressive fluid resuscitation until
operative intervention improves the
outcome.
IV Fluid Restriction
Tentative Hypothesis:
At this time, intravenous fluid
resuscitation should probably be delayed
until hemostasis is obtained.
IV Fluid Restriction
Literature has primarily
looked at penetrating
trauma.
The role of fluid
resuscitation in patients
with blunt trauma is less
clear.
Further studies are
needed.
IV Fluid Restriction
Current recommendation
for blunt trauma is to
administer just enough
fluid to maintain
perfusion.
Rapid, high-volume fluid
administration is
discouraged.
IV Fluid Restriction
Fluid resuscitation
may be of value in
patients who are
moribund with
systolic pressures
<40 mmHg.
IV Fluid Restriction
Patients with
hypotension due to
severe hemorrhage from
isolated extremity
injuries may do better
with aggressive
prehospital IV fluid
resuscitation after
hemostasis.
IV Fluid Restriction
Complications of preoperative fluid
resuscitation:
Secondary bleeding or acceleration of ongoing
hemorrhage
Adult respiratory distress syndrome (Danang Lung)
Sepsis
Coagulopathies
Renal failure
IV Fluid Restriction
Conclusions:
More research is needed.
Data on penetrating trauma is compelling.
Fluid resuscitation probably indicated for moribund
patients.
Best management strategies for blunt trauma and head
injuries is to administer just enough fluid to maintain
perfusion.
Rapid transport probably remains the best treatment for
most trauma cases.
IV Fluid Restriction
Limitations:
Most studies on urban trauma patients with
short transport times.
Findings may not be applicable to rural
trauma patients.
Permissive Hypotension
Should prehospital
personnel attempt to
restore blood pressure in
trauma patients to pretrauma levels or practice
permissive hypotension?
Permissive Hypotension
Animal studies in the 1980s and 1990s
indicated that treatment with IV fluids
before hemorrhage was controlled
increased the mortality rate, especially if
the blood pressure is elevated.
Permissive Hypotension
Human research
seems to support
this premise.
Primarily the Bickell,
Wall, Pepe, et al.
study previously
detailed.
Permissive Hypotension
There is a natural physiologic
compensation when blood pressure is
maintained between 70-85 mmHg.
Urine output and cerebral perfusion
usually maintained when the BP is within
this range.
Permissive Hypotension
Elevation of BP to pre-injury levels,
without hemostasis, has been associated
with:
Progressive and repeated re-bleeding
Decrease in platelets and clotting factors.
Dislodgement of a clot at the site of injury.
Permissive Hypotension
Interestingly, the
standard treatment for
ruptured AAAs has been
to keep patients
hypotensive until
proximal control of the
aorta (above the leakage)
is attained.
This preserves
intravascular blood
volume and prevents
new additional blood
loss from the rupture.
Permissive Hypotension
Large animal studies
of uncontrolled
hemorrhage indicate
that the clot is
“popped” at about 80
mmHg systolic
pressure.
This level has been
reproducible in
human subjects.
Permissive Hypotension
Many hypothesize
that one should not
raise blood pressure
to more than ¾ of
pre-injury levels (~80
mmHg).
Permissive Hypotension
Dutton RP, MacKenzie CF, Scalea TM, et al. Hypotensive
resuscitation during active hemorrhage: Impact on in-hospital
mortality. J Trauma. 2003;52(6):1141-1146
110 patients with hemorrhagic shock were randomized
into two groups: BP maintenance > 100 (n=55) or BP
maintenance of 70 (n=55).
Conclusion: Titration of initial fluid therapy to a lower
than normal SBP during active hemorrhage did not
affect mortality in this study. Reasons for the
decreased overall mortality and the lack of
differentiation between groups likely include
improvements in diagnostic and therapeutic
technology, the heterogeneous nature of human
traumatic injuries, and the imprecision of SBP as a
marker for tissue oxygen delivery.
Permissive Hypotension
Holmes JF, Sakles JC, Lewis G, Wisner DH. Effects of delaying fluid
resuscitation on an injury to the systemic arterial vasculature. Acad Emerg Med.
2002;9(4):267-274
21 sheep underwent thoracotomy and transection of
the left internal mammary artery.
Group 1: No fluid resuscitation
Group 2: Resuscitation 15 minutes after injury
Group 3: Resuscitation 30 minutes after injury
CONCLUSIONS: Rates of hemorrhage from an arterial
injury are related to changes in mean arterial pressure.
In this animal model, early aggressive fluid
resuscitation in penetrating thoracic trauma
exacerbates total hemorrhage volume. Despite
resumption of hemorrhage from the site of injury,
delaying fluid resuscitation results in the best
hemodynamic parameters.
Permissive Hypotension
This paradigm shift
has significant
implications on
emergency care:
Trendelenburg
position
Use of rapid infusers
Intraosseous
infusions
Permissive Hypotension
Fluid restriction and
permissive
hypotension go
hand-in-hand.
Fluid resuscitation
should be
administered in small
boluses to maintain
peripheral pulse
(systolic BP +/- 80
mmHg)
Permissive Hypotension
“During prolonged transport
the prehospital care provider
must attempt to maintain
perfusion to the vital organs.
Maintaining the systolic blood
pressure in the range of 8090 mm Hg or the MAP in the
range of 60-65 mm Hg, can
usually accomplish this with
less risk of renewing internal
hemorrhage.”
Permissive Hypotension
“Gain IV access en route but
give only enough Ringer’s
lactate solution or normal
saline solution to maintain a
blood pressure high enough
for adequate peripheral
perfusion. Maintaining
peripheral perfusion may be
defined as producing a
peripheral pulse, maintaining
level of consciousness, or
maintaining blood pressure
(90-100 mm Hg systolic).”
Permissive Hypotension
What about patients
with TBI?
Traumatic Brain Injury
Oxygenation and Blood Pressure
Hypoxemia (<90% SpO2) and/or hypotension
(<90 mm Hg systolic) are associated with
poor outcomes.
Pulse oximetry and blood pressure must be
monitored.
Continuous waveform capnography
beneficial.
Traumatic Brain Injury
Oxygenation and Blood Pressure
In children, hypotension is:
0-1 year: Systolic <65 mm Hg
2-5 years: Systolic < 75 mm Hg
6-12 years: Systolic < 80 mm Hg
13-16 years: Systolic < 90 mm Hg
Traumatic Brain Injury
Why does TBI require a higher systolic BP than
required for permissive hypotension?
CPP = MAP- ICP
MAP = [DBP+1/3 (SBP-DBP)]
Traumatic Brain Injury
Slightly higher
systolic pressure
may be required to
maintain CPP in
TBI.
Audience Participation
In regard to hemoglobin-based oxygen
carrying solutions:
A. I have administered them in the
prehospital setting.
B. I have seen them administered in the
prehospital setting.
C. I have read about them but never seen
them.
D. I have never heard of them.
E. None of the above.
Oxygen-Carrying IV Fluids
Do oxygencarrying IV fluids
have a future role
in prehospital
care?
Oxygen-Carrying IV Fluids
Crystalloid solutions
have been the
primary IV fluid used
in prehospital trauma
care in the United
States.
Oxygen-Carrying IV Fluids
In most
Commonwealth and
in many Latin
American countries
colloids [polygeline
(Haemaccel)] is used.
HBOCs
Each molecule of
hemoglobin can
carry 4 molecules of
oxygen.
HBOCs
The amount of
oxygen on the
hemoglobin (oxygen
saturation) is
dependent upon the
partial pressure of
oxygen.
HBOCs
The amount of
oxygen that can be
transported is also
dependent upon the
amount of circulating
red blood cells and
the hemoglobin
contained within.
HBOCs
Blood loss and
crystalloid fluid
therapy decreases
the percentage of
circulating red blood
cells and
hemoglobin.
Oxygen-Carrying IV Fluids
Perflurocarbon emulsions
Hemoglobin-based oxygen carrying
solutions (HBOCs):
PolyHeme®
Hemopure®
HBOCs
Hemopure®
Derived from bovine blood
Approved for use in South Africa
Intensive study underway in the US.
HBOCs
HBOCs
Hemopure®
Jul 2002:
Sep 2002:
Nov 2002:
Feb 2003:
FDA application filed.
US Army provides $908,900.00 grant to
conduct single-center trial in trauma
patients.
Trial expanded to include both inhospital and prehospital patients.
Congress awards $4 million to fund
clinical trials. First trials in Dallas with
DFR and Parkland.
HBOCs
HBOCs
PolyHeme®
Solution of chemically-modified hemoglobin
derived from discarded donated human
blood.
Hemoglobin extracted and filtered to remove
impurities.
HBOCs
PolyHeme®
Chemically-modified to create a polymerized form of
hemoglobin designed to avoid problems previously
experienced with hemoglobin-based blood
substitutes:
Vasoconstriction
Renal dysfunction
Liver dysfunction
GI distress
Polymerized hemoglobin incorporated into a
solution that contains 50 grams of hemoglobin per
unit (the same as transfused blood).
HBOCs
HBOCs
PolyHeme®
Product must be refrigerated.
Shelf-life is 1 year.
Clinical prospective randomized controlled trial of
prehospital usage started Sep 2003 in several US
cities (1-year, 700-800 patients).
Paramedics cannot be blinded for study as
PolyHeme looks like blood.
Patients who receive PolyHeme will receive up to 6
more units if needed during the first 12 hours.
HBOCs
California
UCSD (San Diego
Scripps Mercy (San Diego)
Colorado
Denver H&H (Denver)
Delaware
Christiana (Newark)
Illinois
Loyola (Chicago)
Indiana
Wishard (Indianapolis)
Methodist Hospital (Indianapolis)
Kentucky
U of K (Lexington)
Minnesota
Mayo (Rochester)
Ohio
Metro Health (Cleveland)
Pennsylvania
Lehigh Valley (Allentown)
Tennessee
UT (Memphis)
Texas
Memorial-Hermann (Houston)
UTHSCSA (San Antonio)
Virginia
Sentara (Norfolk)
VCU (Richmond)
HBOCs
Artificial polymerized hemoglobin can
transport oxygen within the plasma.
HBOCs
Gould SA, Moore EE, Hoyt DB, et al. The first randomized
trial of human polymerized hemoglobin as a blood
substitute in acute trauma and emergency surgery. J Am
Coll Surg. 1998;187(2):113-20
44 trauma patients (33 male, 11 female) were
randomized to receive red cells or PolyHeme as their
initial fluid replacement after trauma.
There were no serious or unexpected outcomes related
to PolyHeme.
CONCLUSIONS: PolyHeme is safe in acute blood loss,
maintains total [Hb] in lieu of red cells despite a marked
fall in RBC [Hb], and reduces the use of allogenic
blood. PolyHeme appears to be a clinically-useful blood
substitute.
HBOCs
Gannon CJ, Napolitano LM. Severe anemia after
gastrointestinal hemorrhage in a Jehovah’s Witness: new
treatment strategies. Critical Care Medicine. 2002;30:1930-1931
50–year-old Jehovah’s Witness had massive UGI bleed from
pre-pyloric ulcer (Hb=3.5 grams). Hemorrhage control with
injection of epinephrine.
Patient became hemodynamically unstable.
Received 7 units of bovine HBOC and human
erythropoietin.
Within 24 hours patient stable and Hb 7.2 grams.
Conclusions: Survival without allogenic blood attained.
HBOCs
HBOCs look quite
promising for prehospital
and battlefield
emergency care.
Further
recommendations await
result of first prehospital
study.
Audience Participation
In my ambulance service, we use medical
helicopters for scene responses:
A. Very Frequently
B. Often
C. Occasionally
D. Rarely
E. Never
Helicopters
Are EMS
helicopters
effective in
decreasing
mortality and
enhancing trauma
care?
Helicopters
Initial studies in the 1980s showed that trauma
patients have better outcomes when
transported by helicopter.
Today, other than speed, helicopters offer little
additional care than provided by ground
ambulances.
Helicopters
The number of
medical helicopters
in the United States
has increased from
400 to >700 in the last
4 years.
Helicopters
Considerations:
Severe injury:
ISS > 15
TS < 12
RTS ≤ 11
Weighted RTS ≥ 4
Triss Ps < 0.90
Non-life-threatening injuries:
Patients not in above criteria
Patients who refuse ED treatment
Patients discharged from ED
Patients not admitted to ICU
Helicopters
Shatney CH, Homan SJ, Sherek JP, et al. The utility of
helicopter transport of trauma patients from the injury scene
in an urban trauma system. J Trauma. 2002;53(5):817-22
10-year retrospective review of 947 consecutive
trauma patients transported to the Santa Clara
Valley trauma center.
Blunt trauma: 911
Penetrating trauma: 36
Helicopters
Mean ISS = 8.9
Deaths in ED = 15
Discharged from ED = 312 (33.5%)
Hospitalized = 620
ISS ≤ 9 = 339 (54.7%)
ISS ≥ 16 = 148 (23.9%)
Emergency surgery = 84 (8.9%)
Helicopters
Only 17 patients (1.8%) underwent surgery for
immediately life-threatening injuries.
Helicopter arrival faster = 54.7%
Helicopter arrival slower = 45.3%
Only 22.4% of the study population were possibly
helped by helicopter transport.
CONCLUSION: The helicopter is used excessively for
scene transport of trauma victims in our metropolitan
trauma system. New criteria should be developed for
helicopter deployment in the urban trauma
environment.
Helicopters
Eckstein M, Jantos T, Kelly N, et al. Helicopter transport of
pediatric trauma patients in an urban emergency medical
services system: a critical analysis. J Trauma, 2002;53:340344.
Retrospective review of 189 pediatric trauma patients
(<15) transported by helicopter from the scene in LA.
Median age: 5 years
RTS > 7 = 82%
ISS < 15 = 83%
Admitted to ICU = 18%
Discharged from ED = 33%
Helicopters
CONCLUSION: The majority of pediatric
trauma patients transported by helicopter
in our study sustained minor injuries. A
revised policy to better identify pediatric
patients who might benefit from
helicopter transport appears to be
warranted.
Helicopters
Braithwaite CE, Roski M, McDowell R, et al. A
critical analysis of on-scene helicopter transport on
survival in a statewide trauma system. J Trauma.
1998;45(1):140-4
Data for 162,730 Pennsylvania trauma patients
obtained from state trauma registry.
Patients treated at 28 accredited trauma centers
15,938 patients were transported from the scene by
helicopters.
6,273 patients were transported by ALS ground
ambulance.
Helicopters
Patients transported by helicopter:
Significantly younger
Males
More seriously injured
Had lower blood pressure
Helicopter patients:
ISS <15 = 55%
Logical regression analysis revealed that when
adjusted for other risk factors, transportation by
helicopter did not affect the estimated odds of survival.
CONCLUSION: A reappraisal of the cost-effectiveness
of helicopter triage and transport criteria, when access
to ground ALS squads is available, may be warranted.
Helicopters
Cocanour CS, Fischer RP, Ursie CM. Are scene flights for
penetrating trauma justified? J Trauma. 1997;43(1):83-86
122 consecutive victims of non-cranial penetrating
trauma transported by helicopter from the scene.
Average RTS = 10.6
Dead patients = 15.6%
Helicopter did not hasten arrival in for any of the 122
patients.
Only 4.9% of patients required patient care
interventions beyond those of ground ALS units.
CONCLUSION: Scene flights in this metropolitan area
for patients who suffered noncranial penetrating
injuries demonstrated that these flights were not
medically efficacious.
Helicopters
Cunningham P, Rutledge R, Baker CC, Clancy TV. A comparison of the
association of helicopter and ground ambulance transport with the
outcome of injury in trauma patients transported from the scene. J
Trauma 1997;43(6):940-946
Data obtained from NC trauma registry from 1987-1993
on trauma patients and compared:
1,346 transported by air
17,144 transported by ground
CONCLUSION: The large majority of trauma patients
transported by both helicopter and ground ambulance
have low severity measures. Outcomes were not
uniformly better among patients transported by
helicopter. Only a very small subset of patients
transported by helicopter appear to have any chance or
improved survival.
Helicopters
Moront ML, Gotschall CS, Eichelberger MR. Helicopter transport of
injured children: system effectiveness and triage criteria. J Pediatr Surg.
1996;31(8):1183-6
3,861 children transported by local EMS
1,460 arrived by helicopter
2,896 arrived by ground
Helicopter transported patients:
ISS <15 = 83%
But survival rates for children transported by air were better than
those transported by ground.
CONCLUSION: The authors conclude that (1) helicopter transport
was associated with better survival rates among injured urban
children; (2) pediatric helicopter triage criteria based on GSC and
heart rate may improve helicopter utilization without
compromising care; (3) current air triage practices result in
overuse in approximately 85% of flights.
Helicopters
Wills VL, Eno L, Walker C, et al. Use of an ambulance-based helicopter
retrieval service. Aust N Z J Surg. 2000;70(7):506-510
179 trauma patients arrived by helicopter during study year.
122 male
57 female
Severity of injuries:
ISS < 9 = 67.6%
ISS ≥ 16 = 17.9%
12 (6.7%) discharged from the ED
46 (25.7%) discharged within 48 hours.
Results:
17.3% of patients were felt to have benefited from helicopter transport
81.0% of patients were felt to have no benefit from helicopter transport
1.7% of patients were felt to have been harmed from helicopter
transport
Helicopters
Bledsoe BE, Wesley AK, Eckstein M, Dunn TM, O’Keefe
MF. Helicopter Transport of Trauma Patients: A MetaAnalysis J Trauma (In Press).
Meta-Analysis of 22 papers with a cohort of 37,350
patients.
ISS ≤ 15 (minor injuries): 60% (99% CI: 54.5-64.8)
TS ≥ 13 (minor injuries): 61.4% (99% CI: 60.8-62.0)
TRISS Ps > 0.90 (minor injuries): 69.3% (99% CI: 58.580.2)
Discharged < 24 hours: 24.1% (99% CI: -0.90-52.6)
Helicopters
70
68
66
64
Percentage
with minor
injuries
62
60
58
56
54
ISS
TS
TRISS
Helicopters (US Accidents)
25
20
15
10
5
0
2004 2002 2000 1998 1996 1994
Accidents
Deaths
Injuries
Helicopters
Occupational Deaths per 100,000/year (U.S. 1995-2001)
80
70
60
50
40
30
20
10
0
74
26
27
5
Air
Farming Mining
All
Medical
Workers
Crew
Source: Johns Hopkins University School of Public Health
Helicopters
An EMS helicopter (HEMS) pilot or
crew member flying 20 hours/week for
20 years would have a 40% chance of
a fatal crash.
Since 2002, more people have been
killed in air ambulance crashes than
aboard U.S. commercial airlines,
though the helicopters travel just a
fraction of the distance.
Conclusions
Helicopter transport of trauma patients is
over utilized.
Utilization criteria must be studied and
revised.
Few trauma patients benefit from
helicopter transport.
Conclusions
Data show that helicopters are over utilized
for trauma scene responses.
Over triage of trauma patients primary factor
Costs and risks may not justify benefit for
the vast majority of trauma patients.
Triage criteria should be based on
physiological parameters and not
mechanism of injury.
Conclusions
More research is
needed.
Proliferation of
helicopter operations
reflects economic
factors more than
patient outcome
factors.
Data may not be
applicable to rural
areas.
Audience Participation
In my opinion, which country has the
best EMS system?
A. United Kingdom
B. United States
C. Australia
D. South Africa
E. France
Airway Management
And then, there is
airway management.
Do you have the rest
of the afternoon?
Audience Questions
Questions?
For details on publications,
presentations, or biography, see:
http://www.bryanbledsoe.com