What is the role of video laryngoscopy in pre-hospital care?
© Voelckel; licensee BioMed Central Ltd. 2014
Published: 7 July 2014
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 complications, and death. In-hospital data derived form 50,760 apparently normal patients undergoing surgery suggest that difficult laryngoscopy occurs in 5.8% . When intubation 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 . Thus, failed intubation rates in the emergency medical service may be as high as 7% .
There is sufficient scientific evidence that videolaryngoscopy 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 suggested . In addition, performance of videolaryngoscopy in patients endangered by mucus, blood or vomitus in the upper airway must be addressed. Finally, videolaryngoscopy will be challenged by typical pre-hospital environmental 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.
Similar to the learning curve for direct laryngoscopy, new airway devices require significant training and experience. Manikin studies do not allow a comprehensive appreciation of the training needed. At present, available studies suggest a fairly low number of intubations needed to obtain the required skills .
Good evidence (Level 1+)
Weak evidence (Level 3)
Subjects at higher risk of difficulty during DL
Known difficult DL
Evidence obtained in pre-hospital studies
The number of randomized control trials (RCT) addressing 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% . The authors concluded that besides some technical shortcomings, pre-study training was insufficient, although operators 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  found the device suitable and useful for prehospital emergency tracheal intubations with complicated airway conditions.
Presently, the data available does not or insufficiently address the specific aspects of intubation in the exposed pre-hospital environment. In addition, some typical problems 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 dominate the field of emergency airway management.
- Shiga T, Wajima Z, Inoue T, Sakamoto A: Predicting difficult intubation in apparently normal patients: a metaanalysis of bedside screening test performance. Anesthesiology. 2005, 103 (2): 429-37.View ArticlePubMedGoogle Scholar
- Breckwoldt J: Expertise in prehospital endotracheal intubation by emergency medicine physicians-Comparing 'proficient performers' and 'experts'. Resuscitation. 2012, 83 (4): 434-9.View ArticlePubMedGoogle Scholar
- Timmermann A, Russo SG, Eich C, Roessler M, Braun U, Rosenblatt WH, Quintel M: The out of hospital esophageal and endobronchial intubations performed by emergency physicians. Anesth Analg. 2007, 104 (3): 619-23.View ArticlePubMedGoogle Scholar
- Swann AD, English JD, O’Loughlin EJ: The development and preliminary evaluation of a proposed new scoring system for videolaryngoscopy. Anaesth Intensive Care. 2012, 40 (4): 697-701.PubMedGoogle Scholar
- DiMarco P, Scattoni L, Spinoglio A, Luzi M, Canneti A, Pietropaoli P, Reale C: Learning curves of the Airtraq and the Macintosh laryngoscopes for tracheal intubation by novice laryngoscopists: a clinical study. Anaesth Analg. 2011, 112 (1): 122-125.View ArticleGoogle Scholar
- Asai T, Liu EH, Matsumoto S, Hirabayashi Y, Seo N, Suzuki A, Toi T, Yasumoto K: Use of the Pentax-AWS in 293 patients with difficult airways. Anesthesiology. 2009, 110 (4): 898-904.View ArticlePubMedGoogle Scholar
- Healy D: A systematic review of the role of videolaryngoscopy in successful orotracheal intubation. Anesthesiology. 2012, 12: 32-PubMed CentralView ArticlePubMedGoogle Scholar
- Trimmel H, Kreutziger J, Fertsak G, Fitzka R, Dittrich M, Voelckel : Use of the Airtraq laryngoscope for emergency intubation in the pre-hospital setting: a randomised controlled trial. Crit Care Med. 2011, 39 (3): 489-93.View ArticlePubMedGoogle Scholar
- Carlson J: Variables associated with successful intubation attempts using video laryngoscopy: a preliminary report in a helicopter emergency medical service. Prehosp Emerg Care. 2012, 16 (2): 293-8.PubMed CentralView ArticlePubMedGoogle Scholar
- Hossfeld B, Frey K, Lampl L, Doerges V, Helm M: Improving glottic visualization in EMS: comparing direct laryngoscopy and C_MAC PM videolaryngoscopy. Poster presentation. 2012Google Scholar
- Cavus E: The C-MAC videolaryngoscope for prehospital emergency intubation: a prospective, multicentre, observational study. Emerg Med J. 2011, 28 (8): 650-3.View ArticlePubMedGoogle Scholar
This article is published under license to 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.