Scenario-ish: To intubate or not to intubate?

[SandpitMedic]

And then there was this....

Intubate.

http://www.emergency-live.com/en/he...i-increases-rate-favorable-neurologic-outcome

And this...

http://www.emergency-live.com/en/health-and-safety/prehospital-airway-management-best-articles-2014

 

[Carlos Danger]

And then there was this....

Intubate.

http://www.emergency-live.com/en/he...i-increases-rate-favorable-neurologic-outcome

And this...

http://www.emergency-live.com/en/health-and-safety/prehospital-airway-management-best-articles-2014

No new information there.

Those links both refer to the same paper, the Bernard study that was done in Australia and published 4 years ago that was already referred to several times in this thread.

 

[Carlos Danger]

I am slowly working on a lit review on this topic. It's slow going because I have a lot of studying to do right now, and I'm also working full time. I may not have it done until late next month.

I've identified about 15 or so studies done on American EMS systems and published between 2000 and now that look at outcomes of TBI patients who are intubated vs. not intubated, as well as a handful more that look at related but technically separate concepts such as RSI vs. non-RSI intubation in this population.

As I said I won't be done for a while, but what I can tell you preliminarily is that there is no data that I have found that shows that patients intubated by American paramedics do better than those who are not intubated.

There are studies that show improvements in those intubated with RSI vs. non-RSI, there are studies that show improvements with intubation + HEMS transport, and there are studies in the European literature that show improvements in outcome using physician-staffed teams. There is also the Bernard study that keeps coming up that was done in Australia which shows mildly improved functional outcomes measured six months later, but no difference in survival or any of the other outcomes that are of primary interest to EMS.

The reality is that there is nothing in the recent American literature that supports routine intubation of TBI patients. In fact most studies show significantly worse outcomes, even after adjusting for injury severity (as best as can be done in retrospective studies, anyway).

If anyone can find find a study that says otherwise, please refer me to it. I've spent hours searching PubMed and references sourced from related papers, but it is certainly possible that I've missed something.

You can argue about this if you want, but you aren't disagreeing with me, you are disagreeing with the aggregate of published medical literature over the past 14 years.

 

[Posterior]

I have a hard time calling a airway "patent" when they have a GCS of 3-4.
I'm not saying I disagree with your decision, but personally I would have pulled the trigger and RSI'd.
I'm only concerned about what would happen enroute, gastric distention, vomit, so-on.

 

[DrParasite]

PHTLS says that there is no need to intubate trauma patients if a BVM and OPA are working well.

That being said, I would think that intubation was indicated in the OP's case. Provided, however, it didn't delay transport to a trauma center.

IIRC, intubation isn't what causes worse outcomes, but rather the delay in transport while a paramedic attempts to intubate. So if you take a look, and can drop the tube successfully in less than a minute, and be on your way to the trauma center, good. I think the argument could be made that intubating (or BAID, which I'm getting more fond of now that I have moved down south) is better to maintain an airway in a moving ambulance, vs being the sole provider with a BVM attempting to maintain a seal while going down the road.

But when you prep for an RSI, you're spending precious time that should be spent going go the trauma center.

BTW, I don't think California paramedics are any worse trained than anyone else. However, CA paramedics are less experienced at intubating, because they don't do it frequently on real people. This is a problem with any all ALS systems (compared to tiered EMS systems), because providers just don't do it enough. California is further hampered because they have so many paramedics (every firefighter, ambulance operator, tow truck driver, and fast food worker is a paramedic looking for a new job), so on a sick calls, you might have 2 to 6 paramedics on a scene, and only one can actually get the tube. Some haven't intubated a real person in the last 12 months. Compare that to my old stomping ground of NJ, when there are paramedics who intubate 2 people a week, and you see who is more experienced at intubations. It isn't about training, it is about using the skills in real patients. To over simplify, anesthesiologists are really good at intubations; psychiatrists, not so much. both are MDs, but one intubates more often.

 

[systemet]

IRC, intubation isn't what causes worse outcomes, but rather the delay in transport while a paramedic attempts to intubate.

For all the pressure to transport rapidly, there's not a much data supporting rapid transport in blunt head injuries.

The arguments against prehospital intubation generally focus on:

(1) Paramedics are less skilled at intubation than physicians and are more likely to expose patients to additional secondary insults, e.g. hypoxia, hypotension, hypercapnia, through prolonged or repeated intubation attempts.

(2) Paramedics are more likely to inadvertently hyperventilate patients once intubated, resulting in a reduction in cerebral blood flow.

Without going to the effort of looking up the primary research, it's clear that this depends on the paramedic and their experience / exposure to intubation, the equipment available to them, and the system in general. Some systems / paramedics are capable of intubating people very safely, and there's some evidence to support the practice, e.g. the Bernard et al. study, above. Others are not. Confounding this, is the likelihood that prehospital intubations represent a high risk group of airways that may be intrinsically more challenging, due to environmental factors, or an increased incidence of difficult airways within the group. This is reflected in some studies involving physicians as well as paramedics.

 

[Brandon O]

"Paramedics intuating TBI in the field" does seem to be a profoundly heterogeneous group.

 

[systemet]

"Paramedics intuating TBI in the field" does seem to be a profoundly heterogeneous group.

Agreed. I think that you and I see that, but that the physicians, as a group, generally don't. There's not a lot of distinction made between someone who graduates from a six month program, and someone who graduates from a 3 year program, or between the person who does tubes on simman, versus the person who gets 50 OR tubes before touching a prehospital patient.

There also seems to be a lack of appreciation that while the TBI group may be very susceptible to poor airway management, many of the other groups of patients that we intubate may have much less risk if there's a period of transient hypoxia, hypotension or hypercapnia.

 

[SeeNoMore]

And really why should Physicans or anyone else have to learn these distinctions? We all have the same cert. It our own fault (as a professoin) that we do not promote a better standard of education andcare. I understand the hesitancy to see complex procedures in the hands of providers who represent such a range of quality.

 

[medicaltransient]

I like the comments with Etomidate only. Has anyone seen the research that says King tubes LMA and comdi tubes occlude the IJ and are harmful to cerebral circulation. Has anyone read the research that sux should never be used in prehospital environment and better outcomes are coming from Vec and Roc as the first and only nmba durring RSI. I will look for the research when I wake up and post it. Goodnight guys!

 

[Carlos Danger]

I think most physicians and others who look at this recognize that there is a broad range of skill levels among paramedics, and also that this is both a challenging population (TBI patients) to manage in the first place, and a challenging environment (the field) to do it in. We are asking a lot here. We take these clinicians (paramedics), give them a fraction of the training that EM docs and anesthesia folks get, and then put them in an especially challenging environment with the most challenging types of patients, and expect them to produce outcomes similar or better than the hospital intubations? Most of us appreciate this, I think.

But still, there is a fair amount of research on this, and it is is pretty consistent on the lack of difference in outcomes. It's not just in CA, either. The Bernard study that keeps coming up was a really decent RCT done in Australia - with paramedics who are generally considered much better trained than most American paramedics - and it showed no improvement in survival with prehospital intubation.

The reason could have something to do with factors that are beyond anyone's control. It could be that very early post-insult, these patients are even more exquisitely prone to the secondary injury that can result from intubation than they are an hour later. It could have more to do with post-intubation management during transport than it does with the intubation itself. Maybe it's related to hyperoxemia from the 100% oxygen that is almost universally used in the field post-intubation. Could it be the drugs - is something different being used for intubation in the ED's than what is being used in the field? There are probably confounders and bias that exist in these studies (they are almost all retrospective) that haven't been considered.

 

[SandpitMedic]

I think most physicians and others who look at this recognize that there is a broad range of skill levels among paramedics, and also that this is both a challenging population (TBI patients) to manage in the first place, and a challenging environment (the field) to do it in. We are asking a lot here. We take these clinicians (paramedics), give them a fraction of the training that EM docs and anesthesia folks get, and then put them in an especially challenging environment with the most challenging types of patients, and expect them to produce outcomes similar or better than the hospital intubations? Most of us appreciate this, I think.

But still, there is a fair amount of research on this, and it is is pretty consistent on the lack of difference in outcomes. It's not just in CA, either. The Bernard study that keeps coming up was a really decent RCT done in Australia - with paramedics who are generally considered much better trained than most American paramedics - and it showed no improvement in survival with prehospital intubation.

The reason could have something to do with factors that are beyond anyone's control. It could be that very early post-insult, these patients are even more exquisitely prone to the secondary injury that can result from intubation than they are an hour later. It could have more to do with post-intubation management during transport than it does with the intubation itself. Maybe it's related to hyperoxemia from the 100% oxygen that is almost universally used in the field post-intubation. Could it be the drugs - is something different being used for intubation in the ED's than what is being used in the field? There are probably confounders and bias that exist in these studies (they are almost all retrospective) that haven't been considered.

Spot on post.

 

[systemet]

And really why should Physicans or anyone else have to learn these distinctions?

I would argue that if a physician is going to be involved in the oversight and direction of prehospital care, then they should know the level of skill and training of *their* providers. Not a group of paramedics in San Diego, King County, or Victoria, Australia. The fact that the group is heterogenous means that what works in one setting may not work in another. This falls under system design and CQI/QA.

We all have the same cert. It our own fault (as a professoin) that we do not promote a better standard of education andcare.

But we don't. The guys in Victoria, Australia don't have the same cert as the guys in San Diego. And is it reasonable to say that the paramedic at King County has the same cert as the paramedic in San Diego? Yes, they're both paramedics in the US, they may both be NREMTPs, but is their initial training, ongoing training, skill exposure and continuing education even remotely similar?

What about a Critical Care Paramedic in Ontario (4 years), an ambulance-nurse in Sweden (5 years), etc? The world doesn't end at the borders of the US, yet the findings from these studies are often extended to systems that are completely different.

I understand the hesitancy to see complex procedures in the hands of providers who represent such a range of quality.

So do I, but I think there's a paucity of research in this area (1 RCT on RSI; 1 RCT on pediatric intubation showing equipoise). I don't think that this question has been settled.

The Victoria study suggests that prehospital RSI can be performed safely (nonsignificant mortality difference), and results in improved neurological outcome (*which is the outcome that really matters). This is a study that excluded patients that were flown. Granted, there's limitations:

* These paramedics were highly trained, worked in a system with strong QI/QA, and underwent a more rigorous training program than *most* (but not all) US paramedics. We don't know if these results are generalizable to other systems.

* The confidence interval for the odds ratio is 1.00-1.64, making it hard to know how large the benefit is. The authors themselves note that a one patient difference in either group takes the p-value from 0.46 to 0.6

So, we don't know the full extent of the benefit, there's a 1 in 20 chance it's spurious, and it's not clear whether you can reproduce this elsewhere.

 

[systemet]

The Bernard study that keeps coming up was a really decent RCT done in Australia - with paramedics who are generally considered much better trained than most American paramedics - and it showed no improvement in survival with prehospital intubation.

True, but disability at 6 months was significantly improved, which is probably more important.

 

[Carlos Danger]

True, but disability at 6 months was significantly improved, which is probably more important.

Functional outcome was statistically improved at six months, but was clinically a very minor improvement.

More importantly, when you consider the length of time that elapsed between the intervention in question (intubation) and the outcome measurement, as well as the innumerable other clinical interventions that a TBI patient would undergo during that interval, all the way from ED resuscitation to ICU care to rehabilitation, as well as all the other individual factors that could potentially affect eventual outcome - none of which were even attempted to be controlled for by this study - I think it is really hard to definitively credit the prehospital intubation with the improved outcome.

 

[systemet]

Functional outcome was statistically improved at six months, but was clinically a very minor improvement.

11 more patients that were able to live independently, travel locally, and buy their own groceries in the prehospital intubation group.

www.tbi-impact.org/cde/mod_templates/12_F_01_GOSE.pdf

I'm not saying being GOSe 5 is a great way to live, but it's a lot better than being a 4.

Granted, you look at the confidence intervals, and run the study again, and there's a 5% chance that that number is 0 (or negative) instead of 11.

More importantly, when you consider the length of time that elapsed between the intervention in question (intubation) and the outcome measurement, as well as the innumerable other clinical interventions that a TBI patient would undergo during that interval, all the way from ED resuscitation to ICU care to rehabilitation, as well as all the other individual factors that could potentially affect eventual outcome - none of which were even attempted to be controlled for by this study - I think it is really hard to definitively credit the prehospital intubation with the improved outcome.

This is why you randomise, though. You're right, you can't control these factors (or at least it's difficult to do so), but you also can't assume they're collectively working in the same direction in the pre-hospital intubation group. Their findings would be strengthened if this was a multi-center trial, or if someone else can reproduce them.

 

[systemet]

Also, once you hit the ICU, you're intubated, they may be aware this was a prehospital intubation when they go through the chart, but they're almost blinded. It's hard to think that they're going to really modify their care based on where that ET tube was put in. Even more so, in the rehab environment, where they probably aren't aware.

 

[Carlos Danger]

The overall difference in GOSe was actually not statistically significant - I was mistaken.

The median GOSe was higher in the paramedic intubation group compared with hospital intubation (5 vs. 3), however, this did not reach statistical significance (P = 0.28).

The median 6-month extended Glasgow Outcome Coma scores were higher in the paramedic intubation group, although this finding did not reach statistical significance. More patients in the paramedic intubation group had cardiac arrest prior to hospital arrival, but the overall mortality rate at hospital discharge was similar in both groups.

I'm skeptical, that's all.

All we are talking about here is performing an intubation roughly 30 minutes earlier (in the field) than it would otherwise have been performed anyway (in the ED). Doing so had no impact on any of the measured physiologic parameters (BP, sp02, pH, Hgb) that are known to be of importance in TBI, or on the early clinical course (ICU days).

It just seems implausible to me that you can do an intervention a little earlier than you would have done it anyway, and even though you find no evidence that changing the timing of the intervention made any difference during the most important phase of the clinical course, still attribute a difference found 6 months later to the change in timing of your intervention.

 

[systemet]

The overall difference in GOSe was actually not statistically significant - I was mistaken.

Yep, but the proportion of patients in the GOSe 5-8 group versus the GOSe 1-4 group was statistically significant (p=0.046): "The proportion of patients with favorable outcome (GOSe, 5–8) was 80 of 157 patients (51%) in the paramedic intubation group compared with 56 of 142 patients (39%) in the hospital intubation group (risk ratio, 1.28; 95% confidence interval, 1.00–1.64; P = 0.046)"

One plausible mechanism is that properly performed intubation / ventilation is protective against episodes of hypoxia and hypercapnia that are devastating to the prognosis of TBI.

 

[Carlos Danger]

One plausible mechanism is that properly performed intubation / ventilation is protective against episodes of hypoxia and hypercapnia that are devastating to the prognosis of TBI.

That's always the assumption, but blood gases on arrival were the same between the groups in this study. Other studies looking at this topic have found similar blood gases, as well.