Just to play the devils advocate, the Melbourne study shows no increase in survivability of patients with TBI that are intubated in the field. Is there a study that shows no increase in survivability of submersion injuries that are intubated in the field? How about reactive airway disease exacerbation refractory to CPAP or pharmacology? Has that been studied?
Submersion injuries requiring intubation are such a small subgroup of prehospital intubation that I doubt anyone has done any outcomes based research. RAD refractory to CPAP is likely more common, but prehospital CPAP is a relatively new intervention in many places. I'm not aware of any research comparing ETI to BVM - it likely hasn't been done. We do know that intubation in RAD is a marker for higher acuity, and that it places patients at a risk for barotrauma, autoPEEP and pneumothoraces. But, in contrast BVM ventilation is likely to be ineffective without some sort of adjunct in patients with very high airway resistances.
I think TBI is usually selected because we know that even a single instance of hypoxia, hypercapnia or hypotension dramatically increases (doubles?) mortality, so its a condition where the patients are very sensitive to airway mismanagement or inadequacies of oxygenation or ventilation. Theoretically, this is where the greatest benefit lies.
I think this illustrates a limitation of EBM - when there's only limited data to extrapolate from, at what point can you start making definitive judgments? I think we both believe that the paramedics in the San Diego trial were substandard, and that the study design had drawbacks, but for a long time this was really the best data out there and it was been taken to be representative of all paramedics. The Melbourne trial may have addressed some of these issues, but it still feels like a loss. Their system was so well optimised, I think I'd expected a bigger difference.
As I mentioned, there are instances when the only method to manage an airway is to sedate a patient and place an endotracheal tube.
Yeah, I know - you can almost start making similar arguments with cricothyrotomy, that its a high acuity, low opportunity event - so do we remove surgical airways because there's evidence of potential harm, no well designed studies showing evidence of benefit, etc.
I think we gave to balance the risks. If we're harming the patients that we most frequently see to help a rare subset - does the math work out in favour in the end?
The real reason intubation may be removed from the paramedic scope is simply because we're not good enough at performing the skill. Every system that pulls intubation goes back to the LA Gauche study that examines BVM versus endotracheal intubation. We all know that study was flawed and that paramedic intubation skills are woefully lacking both in education and continued competency.
The problem is that all studies are flawed, or to be more polite, "have their limitations". We can't discount Gauche et al. just because we don't like aspects of the design - instead we need a study with a similar or better design showing a different result. Right now there's not really much there.
So maybe we need to examine the ability of paramedics to successfully perform endotracheal intubation before we start to look at its efficacy. A novel idea I know... let's teach people how to do it correctly and determine if it's truly needed before we determine if it actually makes any difference.
I agree - but unless we improve the initial training and education soon, it's going to be too late. The judgment is going to be that we can't or shouldn't do these things, and that's all that's going to be remembered.
