Wolfgang G Voelckel

Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine

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What is the role of video laryngoscopy in pre-hospital care?

EXTENDED ABSTRACT Open Access
What is the role of video laryngoscopy in pre-
hospital care?
Wolfgang G Voelckel1,2
From London Trauma Conference 2013
London, UK. 10-13 December 2013
Background
Direct laryngoscopy is the primary method for performing
tracheal intubation in the pre-hospital setting. Failure to
quickly establish an airway can result in hypoxemia,
aspiration, neurologic damage, cardiovascular complica-
tions, and death. In-hospital data derived form 50,760
apparently normal patients undergoing surgery suggest
that difficult laryngoscopy occurs in 5.8% [1]. When intu-
bation is required in a pre-hospital scenario, the incidence
of difficult laryngoscopy is doubled even when experienced
anaesthesiologists are involved, and expected to reach
some 20% when less qualified operators are in charge [2].
Thus, failed intubation rates in the emergency medical ser-
vice may be as high as 7% [3].
Technique
Videolaryngoscopy is a relatively new technology devel-
oped to improve the success rate of tracheal intubation. A
high-resolution micro camera mounted on the tip of a
curved blade connected to small portable digital monitor
improves the view of the vocal cords and subsequently the
success rate of direct laryngoscopy. During direct laryngo-
scopy, the operator visualizes the larynx from outside the
oral orifice. The distance between the vocal cords and the
laryngoscopist’s eye is significant (30–40 cm). This reduces
the angle of view to some 15° with a classic laryngoscope.
Suboptimal alignment of the oral-, pharyngeal- and laryn-
geal-axis, as well as multiple anatomic orpathologic factors
can make direct visualization of the airway difficult or
even impossible. Videolaryngoscopy significantly widens
the angle of view since the digital camera and light source
are inserted very close (2–3 cm) to the larynx.
Videolaryngoscopes or alternative optic devices pro-
viding a “view around the corner” may be categorized
according to design, handling and guidance of the tra-
cheal tube.
General considerations
There is sufficient scientific evidence that videolaryngo-
scopy improves the visualization of the vocal cord when
established scoring systems such as the Cormack and
Lehane scale are employed. It is noteworthy that despite
an improvement in view, the operator may still be unable
to pass a tracheal tube through the glottis. Thus, the key
to a successful outcome is not solely due the view obtained
but related to the ease of inserting the tracheal tube. This
must be considered in future studies evaluating the role of
videolaryngoscopy in the pre-hospital setting. In this
regard, a three part scoring system comprising the device
employed, the view (full, partial, none) and the ease of
intubation (easy, modified, unachievable) has been sug-
gested [4]. In addition, performance of videolaryngoscopy
in patients endangered by mucus, blood or vomitus in the
upper airway must be addressed. Finally, videolaryngo-
scopy will be challenged by typical pre-hospital environ-
mental obstacles, i.e. bright ambient light, humidity, rain,
snowfall, extreme cold or heat. In this regard, a robust and
reliable device is key when used outside the hospital.
Learning curve
Similar to the learning curve for direct laryngoscopy,
new airway devices require significant training and
experience. Manikin studies do not allow a comprehen-
sive appreciation of the training needed. At present,
available studies suggest a fairly low number of intuba-
tions needed to obtain the required skills [5].
Scientific evidence
Studies and case reports suggest that intubation success
rates may be as high as 99% when direct laryngoscopy was
impossible [6]. However, in a systematic review addressing
1Department of Anaesthesiology and Critical Care Medicine, AUVA Trauma
Centre Salzburg, Austria
Full list of author information is available at the end of the article
Voelckel Scandinavian Journal of Trauma, Resuscitation and Emergency
Medicine 2014, 22(Suppl 1):A6
http://www.sjtrem.com/content/22/S1/A6
© 2014 Voelckel; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in
any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://
creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Figure 1 Van Zundert A BJA 2012
Figure 2 Healy D Anesthesiology 2012
Voelckel Scandinavian Journal of Trauma, Resuscitation and Emergency
Medicine 2014, 22(Suppl 1):A6
http://www.sjtrem.com/content/22/S1/A6
Page 2 of 4
the potential role of videolaryngoscopy in successful oro-
tracheal intubation [7], the evidence found for efficacy in
difficult airway management was limited (Table 1).
Evidence obtained in pre-hospital studies
The number of randomized control trials (RCT) addres-
sing videolaryngoscopy in the pre-hospital setting is still
low. Presently, there is only one RCT comparing direct
laryngoscopy (DL) with the AirTraq in 212 patients.
Success rates for DL were found to be 98% whereas the
AIrTraq intubation success was as low as 47.2% [8]. The
authors concluded that besides some technical shortcom-
ings, pre-study training was insufficient, although opera-
tors felt confident using the device. Preliminary reports
and prospective observational studies addressing the
C-Mac videolaryngoscope in helicopter [9,10] and ground
emergency medical services [11] found the device suitable
and useful for prehospital emergency tracheal intubations
with complicated airway conditions.
Conclusion
Presently, the data available does not or insufficiently
address the specific aspects of intubation in the exposed
pre-hospital environment. In addition, some typical pro-
blems such as on-going bleeding or vomitus in the upper
airway have still not been evaluated in pre-hospital RCTs.
Since the C-Mac videolaryngoscope (K. Storz, Tuttlingen
Germany) combines a conventional designed laryngoscope
with video imaging, this concepts merits appreciation and
may already be implemented in field care.
In conclusion, videolaryngoscopy is a rapidly growing
technology. In the future, video laryngoscopy will domi-
nate the field of emergency airway management.
Competing interests
The author declares no conflict of interest with the devices or the
technology addressed in this summary.
Authors’ details
1Department of Anaesthesiology and Critical Care Medicine, AUVA Trauma
Centre Salzburg, Austria. 2ÖAMTC Air Rescue, Vienna, Austria.
Published: 7 July 2014
References
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Table 1
Good evidence (Level 1+) Weak evidence (Level 3) No evidence
Subjects at higher risk of difficulty during DL Airtraq Bonfils McGrath
CTrach Bullard
GlideScope
Pentax AWS
V-MAC
Known difficult DL Airtraq McGrath
Bonfils V-MAC
Bullard
CTrach
GlideScope
Pentax AWS
Failed DL Airtraq Bullard
Bonfils V-MAC
CTrach
GlideScope
McGrath
Pentax AWS
Voelckel Scandinavian Journal of Trauma, Resuscitation and Emergency
Medicine 2014, 22(Suppl 1):A6
http://www.sjtrem.com/content/22/S1/A6
Page 3 of 4
11. Cavus E: The C-MAC videolaryngoscope for prehospital emergency
intubation: a prospective, multicentre, observational study. Emerg Med J
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doi:10.1186/1757-7241-22-S1-A6
Cite this article as: Voelckel: What is the role of video laryngoscopy in
pre-hospital care? Scandinavian Journal of Trauma, Resuscitation and
Emergency Medicine 2014 22(Suppl 1):A6.
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Voelckel Scandinavian Journal of Trauma, Resuscitation and Emergency
Medicine 2014, 22(Suppl 1):A6
http://www.sjtrem.com/content/22/S1/A6
Page 4 of 4


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What is the role of video laryngoscopy in pre-hospital care?

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