Tim Wallace, emergency nurse, midwife and flight nurse from the Top End, returns to the blog with a different look at a popular topic – airway management.
Some stuff to ponder for the non-intubators…
Do you routinely assess, plan and prepare for airway issues in patients with a risk of airway compromise?
Could you honestly say you would be able to reliably manage A and B on your own?
Who does the work?
Emergency airway and ventilation management is routinely performed by a group of providers that it would be reasonable to call airway non-experts. This group includes paramedics, nurses, lifeguards and community first responders. Amongst these individuals there is significant variability in initial & ongoing training, experience and exposures to relevant simulated and actual airway/ventilation management.
A 2011 audit using data from 16 US states (Wang et al table 1) reveals 23% of interventions that could be classified as ‘critical care’ level, and while it is impossible to determine the skill level of the providers who performed the other 77%, it is reasonable to assume that they were not all critical care clinicians.
Conversely, the narrative and evidence base is dominated by the group who probably perform the lowest volume of work (the intubators). While I’m not arguing that we’ve heard the final word on interventions like pre-hospital RSI, I figured it was time to talk about the non-intubators, which for the purposes of this discussion I’m going to limit to paramedics and nurses – not necessarily novices and not necessarily inexperienced.
Whilst I have ignored endotracheal intubation (ETI) and those trained to do it as any casual observer will recognise the internet is bursting at the seams with content on advanced airway management. At times I get the impression from the blog/social media world that intubation (with ketamine) is some kind of panacea. If we glance over at the situation for our “occasional intubator” (typically medical or paramedic) who performs between 1 and 50 people per year (Reeves & Skinner 2008), there is acknowledgment of and significant controversy in the state of affairs around procedural success and risk.
I think it’s reasonable that we apply the same scrutiny to the non-intubators.
Really Simple Things
Simple airway management and bag-valve-mask (BVM) ventilation are simple yeah?
I’ll try to avoid the term ‘basic airway management’ because I don’t really think it’s very basic; positioning, manoeuvres, suction, BVM, oral and nasal airways etc. I’ll also chuck in intermediate-advanced airways like LMAs (laryngeal mask airways) as we are generally all trained and expected to use them if required.
Despite how these skills are represented in many courses and the common fallacy within the health system that completion of an Advanced Life Support course confers reliable competence in advanced life support (alluded to by Kidner and Laurence, 2006), it turns out in the hands of the less skilled/experienced operator, it can be very difficult to achieve airway control and maintain ventilation. Anaesthetists don’t really represent basic airway management as basic, so the rest of us probably shouldn’t either.
The Literature and BVM
Unsurprisingly, Walsh et al (2000) demonstrated anaesthetists were better at BVM ventilation than other doctors, supporting the notion that training, experience and exposures matter when it comes to this skillset. The evidence-based consensus (e.g. Otten et al, 2014) is that 2 handed (versus 1 handed C-grip) BVM technique is superior. However, while 2-person BVM (outside the OT) should be the stated aim, this is not an option on a nurse-only retrieval or in the back of a moving ambulance. Interestingly, in this experiment subjects with more experience bagging people in emergencies did not perform better than inexperienced subjects, though you would imagine this might change if you introduced a toothless bearded man with down syndrome into the mix.
In Noordergraaf et al’s useful 2004 study on real (anaesthetised) people, fire-fighters with 3 hours training on airway/ventilation management attempted to maintain airway patency and deliver BVM ventilation. Up to 23% of the time, they could not maintain an airway using BVM, simple manoeuvres and adjuncts. Additionally, half the time the patients received ineffective ventilation.
In 2011, Adelborg et al evaluated professional life-guard resuscitation performance, comparing mouth to mouth/pocket mask and BVM ventilation. Noting that amongst some lifeguards it was “common sense that BVM [was] superior” (despite the fact that it wasn’t a mandatory part of lifeguard training), their results demonstrate that this is probably a flawed assumption.
Finally, the Finns revealed ‘basic airway management’ for what it is, amongst a cohort of new/clinically inexperienced paramedics, who were allocated a cardiac arrest scenario utilising either BVM, LMA or ETI management after initial training – the group that achieved the poorest ventilation (and by inference airway control) were in the BVM arm! (Kurola et al 2004).
That’s OK, these days we don’t even bother with BVM …
The literature generally suggests LMA devices (v BVM) are easier to learn to use and are superior for airway control / ventilation with a number of people pretty much advocating canning the BVM and going straight for a LMA. Rechner et al (2007) showed that Critical Care Nurses with one hour of training on LMA insertion were able to maintain airway control and ventilate children 82% of the time using LMAs compared to 70% using BVM/adjuncts. Further, utilising LMAs (as opposed to BVM) in initial airway management of cardiac arrests appears to protect arrestees from gastric aspiration (Stone, Chantler, Baskett 1998).
However, while LMAs are undoubtedly the shizz and minimally experienced providers can generally insert them easily enough while supervised in the OT or during manikin simulation, success with this device does not appear to reliably carry over to the real life setting e.g. Hein et al 2008 with 65% success within 2 attempts during out of hospital cardiac arrest.
Now here’s a few useful acronyms I first came across at Life in the Fast Lane:
Difficult BVM = BONES
- No teeth
- Sleep Apnea / Snoring
Difficult LMA = RODS
- Restricted mouth opening
- Distorted airway
- Stiff lungs or c-spine
I was at a recent conference ‘show and tell’ type talk from a representative of a very high-performance paramedic based EMS system. Amongst other things, he talked about the level of audit and scrutiny applied to pre-hospital RSI performed by his service. At the end I asked if they audited the airway interventions/management of their non-RSI accredited providers (no). Realistically this group of providers will still be called upon to manage A and B, and when they do it’s likely to be because there is no backup available – I’m picturing a patient in some kind of extremis. Due to the clinical characteristics of this patient group (cardiac arrest, neurological emergencies, respiratory decompensation etc.), I’d imagine that if there was a negative outcome, it may be difficult to trace it back to a failure of some basic intervention in the kind of way you could if they were performing intubation +/- RSI.
In an methodologically dodgy study conducted by me (2016), non-physician providers (n=I can’t remember), were asked “if you were by yourself and had to bag someone, would you be confident that you could do it successfully?” The responses were generally polarised reflecting unflinching confidence in their abilities or cautionary pessimism that they would give it their best shot but were not optimistic – one told me “if they were honest with themselves most people would ”. This observation appears to mirror the findings of Kidner and Laurence (2006), who evaluated the basic airway and ventilation competence of junior doctors (n=20) on anaesthetized theatre patients. While pre assessment 85% said they were confident in their ability, only 40% demonstrated initial competence to the minimum standard.
Where do you work?
There is a certain irony in our office at work. Over the way in aviation, our pilots are becoming more skilled and experienced almost every shift undertaking high risk, single pilot operations day and night. Yet they still have high volume training and re-currency requirements. Arguably, if they crash the plane we’re all screwed, but I’m not the first person to articulate the idea that we medical people have some lessons to learn from aviation. Raatiniemi et al (2013) have some suggestions about how to rectify the current state of affairs (from a setting that has practical similarities with EMS operations in rural and remote Oz):
– targeted airway management courses (not that such a thing actually exists!)
– simulation and manikin training
– supervised hands on time in OT (probably the gold standard)
– registering / auditing procedures to target training and supervision.
Care to Read More?
Here’s a good blog post on two v one person BVM and some other BVM stuff.
Flavel and Boyle’s excellent 2010 LMA vs BMV is worth a read (the full reference is below).
Additionally, Dr Aaron Conway’s research project “Survey to improve the quality of the training and education that nurses receive about conscious sedation” is worth pondering for the non-airway experts and I imagine the results of this study will provide an important contribution to this discussion. Check it out in detail here.
Now the bibliography:
Adelborg, K., Dalgas,C., Lerkevang Grove, E., Jørgensen, C.,Husain Al-Mashhadi, R., Løfgren, B. (2011) Mouth-to-mouth ventilation is superior to mouth-to-pocket mask and bag-valve-mask ventilation during lifeguard CPR: A randomized study. Resuscitation 82, 618–622.
Flavel, E, Boyle, M. (2010) Which is more effective for ventilation in the prehospital setting during cardiopulmonary resuscitation, the laryngeal mask airway or the bag-valve-mask? – A review of the literature. Journal of Emergency Primary Health Care. 8(3)
Kurola, J. Harve, H. Kettunen, T., Laakso J.-P. Gorski, J. Paakkonen,H. Silfvast, T. (2004) Airway management in cardiac arrest—comparison of the laryngeal tube, tracheal intubation and bag-valve mask ventilation in emergency medical training Resuscitation 61 149–153
Noordergraaf, G, van Dun, PJ, Kramer, BP, Schors, MP, Hornman, HP, de Jong, W, Noordergraaf, A. (2004) Airway management by first responders when using a bag-valve device and two oxygen-driven resuscitators in 104 patients. European Journal of Anaesthesiology, 21(5)
Otten, D, Liao, M, Wolken, R, Douglas, I, Mishra, R, Kao, A, Barrett, W, Drasler, E, Byyny, R, Haukoos, J (2014) Comparison of Bag-Valve-Mask Hand-Sealing Techniques in a Simulated Model. Annals of Emergency Medicine, 63(1)
Rechner JA, Loach VJ, Ali MT, Barber VS, Young JD, Mason DG. (2007) A comparison of laryngeal mask airway with facemask and oropharyngeal airway for manual ventilation by critical care nurses in children. Anaesthesia. 62:79.
Stone, BJ., Chantler, PJ, Baskett, PJF. (1998) The incidence of regurgitation during cardiopulmonary resuscitation: a comparison between the bag valve mask and laryngeal mask airway Resuscitation 38 3–6