Although Britain and Ireland appear to be really rather fabulous at Rugby….thought I’d get that in there….., I do worry that we are falling behind the curve in terms of laryngoscopy in the ED. If you follow many of the luminaries on twitter such as Scott Weingart and Jo Deverill you might think that you are delivering poor quality care if you are still using the old Macintosh blade and struggling to see the larynx. If only you had a video laryngoscope you would be a much better doctor, your patients and staff would think you are fabulous and you would rightly be at the cutting edge of clinical care.
Back in Virchester we don’t use a video laryngoscope, we have access to an AMBU scope in the ED and the gas-board can bring something posher from theatre, but it is by no means routine. We also carry Airtraq scopes in the difficult airway trolley as a rescue device (but without video attachment).
The problem is that in ‘#FOAM world’ I still feel that I am behind the curve on this (geddit). Minh and Tim make me feel inadequate quoting paper after paper on the benefits. It’s not everyone though, I think Cliff Reid has also commented about why they don’t use VL in the HEMS arena – to summarise – because they don’t appear to have a need for it….. failed intubations are rare after all.
However, I still feel bad and that perhaps I really am missing out. That’s why this paper caught my eye this week. Unlike many studies on the use of different airway techniques this is an RCT looking at patient outcomes between video (Glidescope) and boring old direct laryngoscopy.
[learn_more caption=”Who was studied”] 623 patients in a trauma receiving unit. All required intubation. Patients were randomised to either normal DL or VL. Data was collected through monitoring and also be review of closed circuit TV in the resus room. This is an excellent way of recording data about times, attempts and difficulties. Much better than retrospectively filling in a form for instance.
There are many video devices out there but in this study they used the glidescope.[/learn_more]
[learn_more caption=”What about outcomes?”] The main outcome in the paper was survival to hospital discharge. This is in contrast to many papers that use proxy measures such as ease of use, laryngoscopic view, time to intubation etc. Survival is a hard outcome and that’s good to see.[/learn_more]
[learn_more caption=”What are the main findings here?”] The headline figure is that VL made no difference to outcome. 9% died in the VL group and 8% in the DL group. This sugegstst that there is no impact on survival which is perhaps not that suprising. One might argue that the potential benefit of VL would only be in a minority of patients with anatomical reasons that lead to DL difficulty. The event rate is also fairly low which may mean that to see a real difference large numbers of patients would be required. [/learn_more]
[learn_more caption=”And the sub-group analyses?”] Ah, one must always be wary of subgroup analyses. The authors point to an increased mortality for GVL in the head injury group (but if the overall mortality in all patients is the same there must be a reverse change in the non head injured group…)
Anyway, they do identify a statistically significant difference in the head injury group and point to differences in time to intubation and hypoxia as a possible mechanism.
It’s tricky to draw firm conclusions here on a sub-group, but the magnitude of the difference (almost twice the mortality in the head injured group with the VL) is of concern and may require further thought for future studies. The number of patient in the severe head injury group represented only 38 out of the 623 in the study. This is then a really small sub group and that makes me cautious about interpreting this finding.[/learn_more]
[learn_more caption=”Any other concerns?”] There were quite a lot of exclusions at the discretion of the attending physician. 210 to be precise and this is unfortunate as they may have represented a group different to those in the trial. The reasons for this are alluded to in the full paper which suggests that certain physicians were not ‘participating fully’, but that may well reflect reality as this is an area where divisions between old and new technologies appear to be fairly firmly held.
I was looking to see if there were differences in case mix that might explain the results, but the characteristics of patients in the DL and VL groups appear similar. This data is not given for the head injury sub group though and I would have liked to see that to help interpret the difference in outcome for those patients.
The other concern, and perhaps the most unfair one is the setting of this study. Take note folks, this is the R. Adams Cowley Shock Trauma centre. This is not St.Elsewhere, it’s arguably even better than St.Emlyn’s at the management of trauma!! Seriously though. This is a world class facility with a faculty to match that specialises in trauma. This will be a group of clinicians who are vastly experienced in the management of trauma and trauma airways. Arguably this is both a great setting to do the study in (as we can hope that the rest of the system runs well), but also a difficult place as the system is not generalisable to other settings.[/learn_more]
[learn_more caption=”So should I buy a video laryngoscope then?”] I’m not sure this study tells me the answer to that, but it does show that in a real clinical setting, with real patients and real trainees the perceived benefit of VL may not be quite as dramatic as we had hoped.
This is only trauma though. Trauma patients are not the entirety of my practice and arguably some of the most tricky airways I see are in other patients. This study does not address the breadth of EM practice.
What I do like is the fact that this study is an RCT of a device. We are used to seeing trials of drugs, but less so for devices and diagnostic tests. Arguably they are just as important and I commend the authors on this paper. For the moment I shall not be leaping in and spending the ever decreasing coffers of the NHS on a VL, but the Jury’s out. In any case, we must remember that SMACCGold is in Queensland next year and I might just need to speak to Jo Deverill….
PS. If you want to know more on this topic there is a follow up post about our use of evidence for device assessment here.
[author] [author_image timthumb=’on’]http://www.stemlynsblog.org/wp-content/uploads/2012/07/Simon-Carley.jpeg[/author_image] [author_info]Simon Carley[/author_info] [/author]