We are considering purchasing the C-MAC D-blade videolaryngoscope and therefore read the study by Batuwitage et al.1 with great interest. The literature available to guide purchasing and use of airway devices is far from robust2 and it has been suggested that studies performed on manikins are of questionable relevance to clinical practice.3 Sadly using a device ‘on loan’ for a few weeks does not provide a realistic idea of how it will perform in an emergency.
Despite the paucity of data, many departments of anaesthesia have already purchased devices that have not and may never be subjected to rigorous clinical trials. For example, there are as yet no reports on the use of the AP Advance videolaryngoscope (Venner Medical, Singapore) in clinical anaesthetic practice.4 We believe that reports on the use of these devices in the ‘real world’ of routine clinical practice, beyond manikin studies and carefully controlled clinical trials, can provide useful pragmatic information on the effectiveness of these devices.
For example, a prospective evaluation of the use of the standard C-MAC (Storz, Tuttlingen, Germany) videolaryngoscope and the intubating laryngeal mask airway (ILMA) was performed at the Royal Free Hospital over a 6-month period (15 January 2011 to 14 July 2011) prior to the purchase of an AP Advance videolaryngoscope (Venner Medical, Singapore).5 The C-MAC videolaryngoscope was used for 148 of 7790 patients (1.9%), whereas the ILMA was not used over the 6-month period assessed.5 We subsequently performed another service evaluation to guide future purchasing by determining whether the availability of the AP Advance had influenced the airway management strategies used on our patients. A prospective review of the usage of the videolaryngoscope, McCoy blades and the ILMA was therefore conducted over a 3-month period (6 May 2014 to 6 August 2014). Indication for use (i.e. necessity or training) was not recorded.
The usage of the C-MAC videolaryngoscope was determined by reviewing its logbooks. The usage of the AP Advance, McCoy blades and disposable ILMA was determined by counting the blades and the ILMA available at the start and at the end of the evaluation period. No replacement blades or ILMA were ordered during the study period. The data were analysed using the χ2 test.
The C-MAC videolaryngoscope was used for 123 of 4239 patients (2.9%) over the 3-month assessment period. Of the blades available for the AP advance videolaryngoscope, only two difficult airway blades and three size 4 Macintosh blades were used. No size 3 blades were used. Only seven McCoy blades were used. No ILMA was used. The use of videolaryngoscopy significantly increased between 2012 and 2014 (χ2 = 12.5; P < 0.0005). Videolaryngoscopy was used far more often than the McCoy blade (χ2 = 134.6; P < 0.0005) and the ILMA. The C-MAC videolaryngoscope was used more often than the AP advance videolaryngoscope (χ2 = 134.9; P < 0.0005).
Expertise and familiarity, as well as the benefits and limitations of a device, influence airway management strategies. Although most anaesthetists are keen to play with new toys, once the novelty wears off they will only use airway management tools regularly if they are effective. Service evaluations such as ours therefore provide useful pragmatic information about the performance of airway management devices in the ‘real world’.
Our data also highlight a trend towards almost complete reliance on the C-MAC videolaryngoscope for the management of difficult airways at our institution. This probably reflects the ease of use of the C-MAC videolaryngoscope which, essentially, enhances Macintosh blade direct laryngoscopy and so does not require a new skill to be learnt.
Current practice defines the airway management skills and strategies of the future. Unfortunately, as demonstrated by Batuwitage et al.,1 it is possible to fail to intubate the trachea despite using a videolaryngoscope. To rescue an unexpectedly difficult airway effectively with the McCoy blade or ILMA when the videolaryngoscope fails or ‘does not do its job’ requires great skill and experience.
The successful use of any advanced airway management device depends on operator skill, judgement and patient selection. Videolaryngoscopy is not a panacea; alternative airway devices, techniques and expertise must be available at the bedside. The anaesthetists of the future will lose several life-saving devices from their armamentarium if they are not exposed to their use.
Until more reliable data are available, we advise that service evaluations such as ours are used alongside Airway Device Evaluation Project Team (ADEPT) guidance2 to select airway devices, (re)-equip difficult airway trolleys and ensure anaesthetists are exposed to a defined range of airway management strategies.
Acknowledgements relating to this article
Assistance with letter: none.
Financial support and sponsorship: none.
Conflicts of interest: none.
1. Batuwitage B, McDonald A, Nishikawa K, et al. Comparison between bougies and stylets for simulated tracheal intubation with the C-MAC D-blade videolaryngoscope. Eur J Anaesthesiol
2. Pandit JJ, Popat MT, Cook TM, et al. The DAS ‘ADEPT’ guidance on selecting airway devices: the basis of a strategy for equipment evaluation. Anaesthesia
3. Rai MR, Popat MT. Evaluation of airway equipment: man or manikin? Anaesthesia
4. Difficult Airway Society. ADEPT list of evidence. http://www.das.uk.com/adept/list
. [Accessed 16 May 2015]
5. Rajendram R, Sugavanam A, Dugdale D, Orr J. Prospective audit of video laryngoscope usage and survey of the devices used in a teaching hospital to manage difficult airways. Anaesthesia
2012; 67 (Suppl 1):35.