Intubation by paramedics using the ILMA or AirTraq, KingVision, and Macintosh laryngoscopes in vehicle-entrapped patients: a manikin study
I have used all 4 devices in hospital and prehospital setting. Overall, the ILMA is the most versatile and resilient device, because its a LMA as well as a reliable conduit for intubation. You can insert it from a number of different positions. It has a learning curve of about 20 successful insertions but this is in fact shorter than DL with a Mac bladed laryngoscope. Look its not perfect and some folks just dont like the idea of blind intubation. Probably the next step is to combine it with USS of larynx to actually see in real time the tube position at the cords or next to them.
I asked some FOAMEd friends to send in their comments :
Flight Paramedic Ben Meadley of PrehospitalPro
Thanks for the opportunity to comment.
This was an interesting article. I’m a fan of the ILMA, so it was encouraging to read the results.
As is widely appreciated, a manikin, no matter how designed, can be more easily and more predictably intubated than a human with a difficult airway, so this is a significant limitation of the study, as acknowledged by the authors.
Sitting under a desk intubating a manikin is very low fidelity. It’s unlikely to factor in a multitude of factors that may occur in the prehospital environment (again, this was acknowledged by the authors).
The study only examined one true video laryngoscope – the KingVision. The AirTraq doesn’t count. I think other video devices such as GlideScope or C-MAC should have formed part of the study to allow for a wider range of comparison.
The comments relating to frequency and success rate of paramedic intubation are erroneous. There are many, many EMS systems in the world (most commonly where there is a specialised cohort of paramedics undertaking ETI) where frequency of paramedic intubation and rate of first or second pass success equal or better that of ED physicians.
The paramedics in the study were very junior, and would not have had a chance to master direct laryngoscopy, would have limited familiarity with the huge range of human airway anatomy, and limited understanding of how to best use each device in a true clinical context.
So, my overall thoughts are that junior, inexperienced, infrequently intubating paramedics may find that the ILMA is best suited to their needs when intubating a manikin under a table! I’d certainly like to see the results of a repeat study where more experienced paramedics were involved, and additional video laryngoscopes were included. Final word: I’m still a fan of the ILMA.
Ben Meadley | MICA Flight Paramedic
and then Ben’s colleague, Matthew Shepherd :
An interesting artricle.
I applaud the authors for seizing the opportunity to perform some prehospital research, as this is an area that needs to increase.
This article has relevance to paramedics and prehospital care providers as it makes you stop and think “what would I do if I was in that situation”? It also details that operators with little experience with intubation would benefit from using ILMA over other intubating methods in cramped and awkward positions.
I believe this study would provide a more accurate result if qualified and experienced paramedics (with intubation skills) were used to evaluate the devices. The “intubators” that were used in the study were not actually “Paramedics” at that point, they were students with very little experience and skills with the differing airway devices.
Performing “in vehicle” intubation as stated in the article is a very rare procedure. I have operated as an Intensive Care Paramedic and Intensive Care flight Paramedic for the last 10 years. During that time the need to intubate someone while trapped in the car in a seated upright position has occurred on one occassion for me. This is a procedure that is done as a last resort and when done, is usually performed with RSI as the pt’s injuries usually are suggestive of brain injury.
Performing this procedure with the “roof on” would only add to the complexity of an already difficult procedure. Within the state of Victoria, I would imagine that any ambulance that is sent to a MCA with entrapment would be closely followed by a “rescue” crew of some description. I would suggest that performing this procedure without the roof being removed is potentially setting yourself up for failure. However, I can accept that under some extreme circumstances, there may be an occassion when a pre hospital team has no choice but to provide airway support by the means of intubation. In these circumsatnces it appears clear that the ILMA would provide the easiest and most efficient means of intiubation. Especially when being performed by a novice operator.
Anterior intubation (being in front of the pt while they are in a seated position) is not a skill that is commonly taught to undergraduate paramedics, and I wonder how much opportunity the students had to practice this skill before being placed “under the table”?
Are VL’s required in the prehospital environment when this paper demonstrates that students can intubate better with ILMA’s?
If you are going to intubate in the prehospital environment, it is important not to be solely reliant on one device to secure your airway.
Having experience and training which includes basic airway manuevres, DL, VL, LMA’s and even surgical airways will ensure that majority of airways are able to be managed without too much dificulty. There will be times when one device works well and another fails, it is important that the “intubator” is adaptable and able to quickly move from one device to another.
This study demonstrates which device is best for operators with little experience working in extremely rare circumstances. Experienced prehospital intubators may provide a completely different result, and therefore further investigation is required to determine which device would be the most successful.
Hope this helps Minh?
MICA Flight Paramedic
And finally PHARM Co-Author, Dr Yen Chow :
Here are some quick thoughts on this. If I have a chance later I will send you some more.
This is a nice little study that is great in highlighting the challenges of prehospital airway management where there may entrapped patients and limited access to the patient. Airway interventions that require the operator’s head or hands to be positioned in a particular way in order to visualize or manipulate the endotracheal tube will be severely challenged by enclosed spaces. Where a view is not required such as the ILMA or where the view can be done on a video screen will have a distinct advantage in such scenarios. A channeled tube delivery method as in the ILMA or channeled King vision or Airtraq would also be advantageous (latter two only if a good view is obtained).
The other distinct advantage of the ILMA is the ability to provide oxygenation and ventilation.
The success rate of intubation as well as the ease of ILMA use in this study is promising however the study is limited by being a mannequin study who is GCS=3, with no airway reflexes and who does not gag and vomit. ILMA has a very good rate of success and in one study of difficult airway patients (Ferson et al. Use of the Intubating LMA-Fastrach(TM) in 254 Patients with Difficult-to-manage Airways. Anesthesiology. 2001 Nov;95(5):1175-81) the success rate for blind intubation was 96.5% in n=200 (75.5 first pass success and 7 failures where 78% were under general anaesthesia, 20% under topical anesthesia/sedation and 2% were unconscious to start).
I think this study is a good reminder of the utility of ILMA for rescue intubation particularly in prehospital care. This would tip the favor in my mind in choosing ILMA as a supraglottic airway of choice and to prioritize this compared to getting an indirect/video laryngoscope. The KingLT does also have an off label method of blind intubation however efficacy and safety has not yet been proven in clinical practice. I have heard that Hennepin County Medical Center is accumulating cases on their method (http://resusreview.com/2013/guided-catheter-technique-for-king-airway-exchange/). In choosing an indirect laryngoscope for prehospital, a screen on blade or separate video display and a channeled tube delivery system appears to be the better options.