Injury, Int. J. Care Injured (2007) 38, 27—33
www.elsevier.com/locate/injury
A review of traumatic airway injuries:
Potential implications for airway assessment
and management§
Carmen Kummer *, Fernando Spencer Netto, Sandro Rizoli, Doreen Yee
2075 Bayview Ave. M200, Toronto, Ontario, Canada M4N 3M5
Accepted 4 September 2006
KEYWORDS
Traumatic airway
injury;
Definitive airway
Summary
Background: Obtaining a patent airway can be difficult in patients with traumatic
airway injuries (TAI). There is a paucity of data available about the incidence of airway
compromise and techniques used in these patients.
Methods: Charts review of all patients with TAI treated in a Regional Trauma Center
from July 1989 to June 2005.
Results: One hundred and four patients were identified as TAI in the study period
(incidence of 0.4% for blunt and 4.5% for penetrating trauma). Sixty-eighty patients
were victims of penetrating trauma (ISS: 24 10; mortality: 16%). Thirty-six patients
were blunt trauma victims (ISS: 33 16; mortality: 36%). Overall, 65% of the patients
received a definitive airway (DA) in the pre-hospital setting or at the initial hospital
assessment. Alternative techniques for obtaining DA including wound tracheal tube,
surgical airway and intubation under fiberoptic bronchoscopy were used in 30% of the
patients. Among 24 deaths, 10 were considered primarily due to the airway injury.
Twelve patients presented with thoracic TAI with nine deaths in this subgroup.
Conclusions: Overall, the incidence of TAI is low. Blunt trauma TAI is less common, and
these patients have a different clinical presentation, higher ISS and mortality than the
penetrating TAI group. Early assessment of airways is crucial and DA was required in 2/3
of the patients with TAI. Lower airway injuries have higher mortality than upper airway
injuries. Even though most patients died as a result of other injuries, causative factors of
death included difficulty in obtaining DA and ventilation/oxygenation problems.
# 2006 Elsevier Ltd. All rights reserved.
§
This paper was presented at the Annual Scientific Meeting of the Trauma Association of Canada, March 23—25, 2006, Banff, Alberta,
Canada.
* Corresponding author. Tel.: +1 416 480 4864; fax: +1 416 480 6039.
E-mail addresses: [email protected] (C. Kummer), [email protected] (F.S. Netto),
[email protected] (S. Rizoli), [email protected] (D. Yee).
0020–1383/$ — see front matter # 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.injury.2006.09.002
28
Introduction
The absolute priority in the initial resuscitation of
any trauma is to secure a patent airway and provide
adequate ventilation.1 Even under the best of conditions, securing a patent airway may be challenging
in a trauma patient, but it is particularly difficult in
patients with traumatic injuries to the airway,2,12 in
whom complex airway management techniques may
be required.11,13 Traumatic airway injury (TAI)
requires high levels of awareness to be diagnosed
and advanced airway management skills. Compounding the technical challenges of securing a
definitive airway (defined as a tube present in trachea with the cuff inflated)1 in these patients, any
airway management intervention may prove useless
if the injury is located distal to the inflated cuff. In
fact, efforts to intubate the trachea can themselves
augment the airway injury and lead to a fatal outcome.2,10
In spite of the clinical relevance, there is a lack of
literature reporting large series of patients with TAI,
data on its frequency and the specific airway management interventions used to treat these patients.
While some studies report that airway trauma is rare
and occurs in less than 1% of all trauma patients,6
many of these patients present with subtle clinical
findings that may be easily missed during the initial
presentation. This is important because undiagnosed airway injuries are sometimes fatal.7,13 Due
to the recent improvements in pre-hospital care,
the initial airway assessment and management is
frequently performed by paramedics and ambulance personnel at the scene of the accident, which
may play a role in the outcome of these patients.
Many concerns on airway trauma remain under
investigated. This study was designed to retrospectively evaluate all traumatic airway injuries seen at
a large Regional Trauma Centre and focus in determining how urgent these cases were considered
initially, the airway management interventions used
during the initial assessment to secure a definitive
airway and the potential impact of these interventions in determining patients’ outcome.
Methods
After approval by the Research and Ethical Boards,
patients were identified from the Trauma Database
of Sunnybrook Health Sciences Centre, Toronto,
Ontario, Canada. Charts were reviewed from all
trauma patients presenting with airway injuries
from July 1989 to June 2004. Inclusion criteria consisted of the diagnosis of traumatic airway injury
(pharynx, larynx, trachea and main bronchi).
C. Kummer et al.
Patients deemed dead on arrival were excluded.
Details regarding the mechanism of injury, clinical
presentation, urgency of presentation, requirement
and type of definitive airway obtained, injury severity scores, associated injuries, diagnostic tests and
initial treatment were collected. Pre-hospital
notes, referring hospital records, anaesthesia and
ICU charts were revised.
For the purpose of this study, pharynx, larynx and
cervical trachea were considered upper airways
while thoracic trachea and main stem bronchi were
defined as lower airways. We defined death as
related with the airway injuries when this was
stated in the patients’ Death Certificate or chart,
or when upon reviewing all circumstances reported
in the patients’ files, the authors of this study (all
trauma experts) concluded that the TAI had an
important causal role.
Data was presented as mean standard deviation, or percentage, as indicated. Differences in
outcome (survival or complications) associated
with mechanism, clinical presentation and airway
management were analysed by Chi-square test,
or t-test as appropriate, accepting p < 0.05 as
significant.
Results
During the study period, 12,187 trauma patients
were treated at Sunnybrook Health Sciences Centre,
of which 104 were diagnosed as having TAI. Of these
patients, 36 suffered blunt trauma, and 68 were
victims of a penetrating mechanism (incidence of
0.4% for blunt and 4.5% for penetrating trauma–—
p < 0.001). Specific details on the mechanisms of
injuries are shown in Table 1. Patients’ demographics and clinical characteristics are listed in
Table 2.
The diagnosis of TAI was definitively established
by surgery in 78 patients (18 blunt, 59 penetrating),
fiberoptic bronchoscopy (FOB) in 11 patients (8
blunt, 3 penetrating), CT scan of the neck in 5
patients (5 blunt, 1 penetrating), FOB and CT scan
in 3 (3 blunt), Coroner’s autopsy report in 5 patients
(1 blunt, 4 penetrating) and by direct laryngoscopy
examination in 2 patients (2 blunt).
In 54 patients (52%), the definitive airway (DA)
was secured before arrival to Sunnybrook by prehospital care personnel either at the scene of the
accident or en route in 32 patients (31%), or at a
referring hospital in 22 patients (21%). Forty-seven
patients (45%) had a DA established at Sunnybrook,
17 patients (16%) in the Trauma Room during initial
assessment and resuscitation and 30 (29%) in
the Operating Room. Among the latter, DA was
Traumatic airway injuries
29
Table 1 Underlying mechanisms resulting in traumatic airway injury
Type of mechanism
Number
Penetrating
Stab wounds
GSW
Shotgun wounds
Other
68 (65%)
44
15
4
5
Blunt
MVC
Pedestrian
Bicycle
Recreational vehicle
Industrial accident
Motorcycle crash
Fall
Other
36 (35%)
17
6
3
3
2
2
1
2
GSW: gunshot wounds; MVC: motor vehicle collision.
established either as part of the treatment of the
TAI or because the patient needed surgery for
injuries unrelated to the airway injury. Overall,
71 patients (68%) required a DA during initial
assessment either at the scene of the accident
or en route to the hospital.
The interventions used to establish a definitive
airway are shown in Table 3. Difficulties in intubating the patients were charted in only 15 patients.
Orotracheal intubation was the most common intervention regardless of the location in which the DA
was obtained, before or after arrival to a hospital.
Thirty patients (29%) required more complex interventions than simple intubation under laryngoscopic
vision to secure DA, including FOB in 11 patients,
surgical airway in 10 patients and temporary intubation through the wound in 9 patients. Patients
that required DA management in the pre-hospital
setting had a significantly higher mortality (19
deaths among 32 patients–—p < 0.0001) and significantly more severe injuries (ISS of 32 compared to
22–—p = 0.01) than the patients receiving DA in the
operating room.
Three patients never required any intervention
for treatment of their airway injuries which were
managed expectantly. One of them had a blunt
trauma of the neck with a mountain bike, and
presented hoarseness, blood in oropharynx and pain
in swallowing. The CT scan showed only hyoid bone
and thyroid cartilage fractures. The other two
patients had penetrating trauma: the first had a
small gunshot wound just above the sternal notch
and underwent fiberoptic bronchoscopy, which
showed a small hole in the anterior trachea with
exit in the antero-lateral tracheal wall. The second
patient was shot in the face and the bullet crossed
the posterior pharynx. The pharyngeal wound was
diagnosed by CT scan. All these patients were
stable, had isolated injuries, were admitted for
monitoring, and were discharged home in 72 h.
A total of 61 (59%) patients required tracheostomy as part of the TAI management, 18 patients
after blunt trauma (50% of all blunt traumas) and 43
after penetrating trauma (63% of all victims of
penetrating trauma). Fifteen patients did not
undergo any form of surgical repair of their TAI,
even when submitted to surgery for indications
other than the airway injury. These patients were
treated with tracheostomy or endotracheal intubation with the cuff inflated distal to the airway lesion.
Upper airway injuries (UAI) occurred more frequently than lower airway injuries (LAI) in both
blunt and penetrating trauma groups. The blunt
Table 2 TAI patients’ demographics and clinical presentation
Male
Age
ISS
Blunt
Penetrating
Overall
31 (86%)
37 16
33 16 *
56 (82%)
36 14
24 10
87 (82%)
36 16
27 13
17
30
22
8
6
2
1
4
6
36
32
26
11
11
8
8
4
13
Symptoms at presentation
SC emphysema
External bleeding
Air escape
Cervical hematoma
Coma/VSA
Stridor
Hoarseness
Asymptomatic
Other
19
2
4
3
5
6
7
0
7
Suicide attempts
Mortality
5 (14%) *
13 (36%) *
*
p < 0.05 comparing blunt and penetrating.
(53%) *
(6%) *
(11%) *
(8%)
(14%)
(17%) *
(19%) *
(19%)
(25%)
(44%)
(32%)
(12%)
(9%)
(3%)
(1%)
(6%)
(9%)
20 (29%)
11 (16%)
(38%)
(30%)
(24%)
(10%)
(10%)
(8%)
(8%)
(4%)
(12%)
25 (24%)
24 (23%)
30
C. Kummer et al.
Table 3 Distribution of the initial airway intervention following location of intervention
Place DA was established (n)
Oral TT
Nasal TT
FOB
Field/route (32)
Referring hospital (22)
Trauma Room (17)
Operating Room (30)
17
17
10
15
9
2
—
1
—
—
6
5
Total (101)
59
12
11
Surgical airway
1
3
—
6a
10
Wound TT
Mortality
5
—
1
3
19 (60%) *
4 (17%) *
1 (6%)
—
9
24 (23%)
DA: definitive airway; TT: tracheal tube; FOB: fiberoptic bronchoscopy; *p < 0.05 when compared to Operating Room.
a
One of the patients who received initial surgical airway was operated only 48 h after admission.
group had 28 patients with UAI and 8 with LAI while
the penetrating group had 62 patients with UAI and 6
with LAI. The anatomical location of the airway
injuries as well as overall mortality and mortality
related with airway injuries is shown in Table 4. LAI
had the highest mortality rate in both groups, blunt
and penetrating ( p < 0.05).
Ten of the 24 deaths (42%) were deemed as
related with the TAI. These cases are summarized
in Table 5. Seven patients had LAI and all had major
problems with regard to adequate ventilation and
oxygenation. Of the patients who died following
UAI, three were victims of penetrating trauma
and arrived at Sunnybrook with absent vital signs,
profound hypoxia and shock. All three patients were
described as being very difficult to secure patent,
definitive airways.
Discussion
There are not many studies on traumatic airway
injuries. The available studies are not homogenous
in their approaches. Therefore, rendering comparisons and recommendations is very challenging.
While some trauma-related studies consider the
pharynx part of the airways,6,9 others restrict the
airways to the larynx, trachea and bronchi.4,5 In the
present study, the pharynx was included as part of
the upper airways. In clinical practice, it may be
difficult during the initial assessment of a cervical
trauma to accurately diagnose whether the patient
had an injury to the larynx, pharynx or cervical
trachea. Likewise, it might also very difficult to
determine whether the clinical presentation of a
TAI is due to an injury to the thoracic trachea or
main bronchi.
Furthermore, to facilitate analysis in the present
review, we arbitrarily opted to divide the airway
injuries into upper and lower airway injuries. This
classification allowed a better evaluation of the
impact of the anatomical location of the injuries
during the two initial steps of the ATLS protocol
assessment for trauma patients: (1) secure the airway/neck stabilization and (2) provide satisfactory
lung ventilation and oxygenation.
In the present study, TAI was identified in 0.9% of
all trauma patients, in 0.4% of the blunt and 4.5% of
the penetrating trauma patients. Similarly, the literature reports that TAI is rare and occurs in less
than 1% of all trauma patients, being more frequent
in penetrating trauma.4,8 The relatively high incidence of penetrating TAI in our population might be
the result of referring bias to our Trauma Centre. Of
note, 20 of the penetrating TAI cases were selfinflicted injuries (29% of penetrating TAI), 18 of
them being stab wounds.
In this series of patients, the initial clinical presentation of the patients with TAI varied accordingly
to the underlying mechanism and location of the
airway injuries. Subcutaneous emphysema was the
most common presentation related to TAI in blunt
trauma, followed by oral bleeding and hoarseness. In
penetrating trauma, the three most common presentations were external bleeding, air leak through the
wound, and subcutaneous emphysema. Although the
retrospective nature of the data collection may fail to
capture less prominent signs and symptoms, the
Table 4 Distribution of mortality by mechanism type and segment injured
Type
Location of TAI (n)
Mortality from TAI
Overall mortality
Blunt
Upper airway injuries (28)
Lower airway injuries (8)
0
5 (63%)
8 (29%)
5 (63%)
Penetrating
Upper airway injuries (62)
Lower airway injuries (6)
3 (5%)
2 (33%)
7 (11%)
4 (66%)
Mortality TAI: mainly caused by airway injury. For both groups (blunt and penetrating), p < 0.05 when comparing upper and lower
airways in each category of mortality.
Summary of 10 deaths related to airway injuries
Mechanism of trauma
Airway injury
Main admission
findings
Placement
of DA
Difficulty in
obtaining DA
Difficulty in
ventilation
Main associated
injuries
ISS
LOS
MVC
R bronchus
Field/route
No
Yes
CHI, flail chest
38
<1d
Crushed by bulldozer
Field/route
Flail chest
26
20d
Yes
CHI, flail chest
51
<1d
Boat collision
R bronchus
Referring
hospital
Field/route
Yes–—multiple
attempts
No
Yes
MVC
Tracheo/
bronchial
R bronchus
Massive hemothorax,
" air leak in CT
Hypoxia, " air leak
in CT
" Air leak in CT,
desaturation
Severe hemoptysis
No
Yes
50
<1d
Pedestrian struck by
train
GSW
L bronchus
Hypoxia and shock
SB TR
No
Yes
50
<1d
VSA
Field/route
No
Not recorded
19
<1d
Stab wound
Thoracic
trachea
Larynx
CHI, R massive
hemothorax
CHI, flail chest,
L hemothorax
Aortic arch
Hypoxia, shock
and coma
Field/route
No
L carotid artery
and jugular vein
35
<1d
GSW
Pharynx
VSA
Field/route
Yes–—tube
through the
wound
Yes–—hypoxic
No
17
<1d
Stab wound
Cervical
trachea
VSA
Field/route
Hemo/pneumothorax
and intra-abdominal
injuries
Hypoxic brain injury
and jugular vein
17
3d
GSW
Thoracic
trachea
VSA
Field/route
Innominate artery injury
21
<1d
Yes–—hypoxic
with intra-oral
bleeding
Not recorded
Yes
No
Traumatic airway injuries
Table 5
MVC: motor vehicle collision; GSW: gunshot wound; R: right; L: left; ": significant; CT: chest tube; VSA: vital signs absence; SB TR: Sunnybrook Trauma Room; CHI: closed head injury.
31
32
different clinical presentations are consistent with
the mechanism of injury. If a wound is present, then
external bleeding is frequently seen. The wound
itself will also allow air leak from the underlying
injured structures. In contrast, in blunt traumas,
often without external wounds, the air leaking from
the underlying traumatised airway will collect in the
subcutaneous tissues resulting in subcutaneous
emphysema, common among these patients.
In the penetrating group, stab wounds represented the most common cause of TAI, followed
by gunshot wounds. We noticed a high number of
self-inflicted injuries associated with stab wounds to
the neck in our hospital. The most frequent mechanism of blunt trauma was motor vehicle collision,
followed by pedestrians.
As expected, patients sustaining blunt TAI had a
higher ISS compared to the penetrating group.4 The
higher severity and often multiple associated injuries account for the higher mortality in this group.
In 32 patients, a definitive airway was established
at the scene of the accident. These patients suffered the most severe injuries, thus had the highest
injury severity score (ISS) and predictably the highest mortality rate. These findings are consistent
with a previous study by Bhojani et al. demonstrating that the urgent requirement for a patent airway
is an independent predictor of mortality.4
Orotracheal intubation was the most common
procedure in both the pre- and in-hospital settings.
The number of nasotracheal intubations was higher
in the pre-hospital setting. Surgical airways and
intubation through the wound were done in both,
pre- and in-hospital settings as the first approach to
secure a patent airway when intubation attempts
were unsuccessful.
Three patients did not require any type of airway
management for TAI and were discharged from the
hospital after a short admission period. Upon admission, these patients were not in respiratory distress
and the definitive diagnosis of TAI was done by CT
and/or fiberoptic bronchoscopy. Among the 78
patients undergoing any type of surgery, 15 patients
(19%) were tracheally intubated (oral or nasatracheal) for the surgery but did not have the airway
injury itself surgically repaired. These findings corroborate the principle that in selected cases, nonoperative management with oxygen supplementation or a tracheal tube placed below the level of the
injury is effective to treat TAI.3 However, most
patients (81%) required some form of direct surgical
repair of the injured airway.
Tracheostomy was performed as part of the definitive management of the TAI in 61 patients (59% of
all patients). It remains the most common form of
surgical treatment for patients with TAI in our insti-
C. Kummer et al.
tution, in isolation or in association with other airway surgical procedures.
In this study, the mortality varied according to
the anatomical location of the airway injury, with
lower injuries (LAI) having the highest mortality
rate. Because the injury may extend beyond the
end of the tracheal tube, patients with LAI, particularly when extensive, are often difficult to ventilate/oxygenate, even after tracheal intubation and
mechanical ventilation. Other investigators have
suggested that extra corporeal membrane oxygenation (ECMO) might be beneficial for the treatment of
such complex airway injuries.13
Of the nine patients that died of a LAI, seven were
related with the airway injury. In this series,
patients with LAI had more severe injuries besides
the airway one, the airway injury was considered as
being of difficult surgical access and consequently
had the highest mortality. Of the seven patients that
died, difficulties in ventilation were reported in
five, and there was enough evidence to suspect that
the other two patients also had a similar problem.
As previously mentioned, of the 24 deaths in this
study, 10 patients (42% of deaths) died as consequence of the TAI, 7 with a lower and 3 with an upper
airway injury. Most of those deaths occurred early in
admission, less than 24 h in eight patients, confirming the immediate physiological consequences of
the lack of a patent airway and failure of oxygenation and ventilation. The other two deaths occurred
following hypoxic brain injury and sequential failures in the suture line of an extensive tracheobronchial injury. This last patient was transiently
treated with ECMO but died in consequence of
complications of this injury.
This study has limitations, many common to all
retrospective studies. The data collection depended
on the information contained in the chart. Details
about the airway management at the scene of the
accident, the referring hospital or en route were
limited. It was not possible to evaluate the training
of all those involved in managing the airway of these
patients or even the number of difficult airways.
Such information could be important in preparing a
trauma team to receive a patient with known TAI.
Furthermore, the link between death and the airway injury was determined subjectively when there
was no clear statement in the patients’ charts.
Conclusion
The overall incidence of TAI remains low. Airway
injury from blunt trauma is less common, has a
different clinical presentation but higher ISS and
mortality compared to penetrating TAI. The early
Traumatic airway injuries
assessment of airways is crucial and a definitive airway is required in most patients with TAI. Alternative
techniques for obtaining DA are frequently required
and include: tracheal intubation through the neck
wound, surgical airway and intubation using fiberoptic bronchoscopy. Patients that required a definitive
airway at the scene of the accident, en route and/or
sustain LAI have a higher mortality. Surgery and
tracheostomy are commonly used for the definitive
treatment of patients sustaining TAI. Even though
most patients died as a result of their other injuries
besides the TAI, causative factors in UAI patients
included difficulty in establishing a definitive airway
and ventilation/oxygenation problems were contributory in LAI patients.
Acknowledgment
This research was undertaken at Sunnybrook Health
Sciences Centre, University of Toronto.
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