Friday, July 18, 2014

On Helicopters, Probability, and Consequence

This morning, I received the horrible news that a fellow instructor for the wilderness medicine education company I work for, a flight nurse/paramedic, was killed in a medical helicopter crash.  I knew him only by reputation, but given our small community it's a safe bet that we would have become good friends, as with so many of the other instructors I've worked with in my time with the company.

This is the second instructor that our professional family has lost to an airmedical crash in roughly 5 years, which is difficult to accept because our company has always believed, and taught our students, that helicopter rescue/transport is inherently high-risk and to be reserved for patients who will truly benefit from that risk.  Lest we leave any ambiguity in our students' minds about "risk", we define it into two components; probability and consequence.  I make it a point in every class I teach to say that although the statistical probability of a helicopter crash is low (http://helicopterannual.org/portals/27/pdf/ann_p2c5.pdf), the human consequences of a crash are often gut-wrenching.

Ironically, this concept (readily understood by professional guides, wilderness education college students, and outdoor enthusiasts) is largely misunderstood or ignored by medical professionals.

We frequently call for helicopter transport of trauma patients who will not benefit from it (http://www.ncbi.nlm.nih.gov/pubmed/16766969).  This study identified that over HALF of patients transported by helicopter had minor injuries.  A quarter of them were discharged from the hospital within 24 hours; internal data from a trauma center in the state I previously lived in upped that number to 50%.  This overtriage of patients not only increases the probability of a crash, but also reduces the cost-effectiveness of helicopter EMS to society (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3999834/).  And even for those patients with "major trauma", the published research doesn't clearly show a significant benefit to helicopter usage (http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD009228.pub2/abstract;jsessionid=F0489278656882C0B38725F70F5A44D3.f03t01).

We need to take a deep breath and evaluate how we use helicopters.

I use the CDC's most recent field triage guidelines to make risk-benefit decisions about flying patients to a trauma center (http://www.cdc.gov/fieldtriage/pdf/decisionscheme_pocketcard_a.pdf).  As a general rule, patients with physiologic instability (step 1) will probably get flown.  Patients with anatomic injuries (step 2) might get flown, based on distance to the appropriate trauma center and time sensitivity of their injuries.  Patients with a concerning mechanism of injury (step 3) or special considerations (step 4) probably WON'T get flown; I'll either take them by ground to the trauma center or to a non-trauma center that has the diagnostic capabilities the patient needs (X-rays, CT scanners, etc.).  Many providers I've worked with in the past have used the mechanism of injury as their sole basis for flying a patient; this is not a very accurate gauge of what care the patient needs (http://www.ncbi.nlm.nih.gov/pubmed/24165248).

It's time to focus on the injuries a patient HAS, not ones they MIGHT have, when we ask three people to risk their lives to transport that patient.

Our colleagues, friends, and mentors are counting on us for that.

8 comments:

  1. I, too, question the use of helicopter ambulances. I'm not sure they're worth the exorbitant overhead. Period. Just because we can doesn't mean we should.

    To your point about cost effectiveness-- if we only flew time sensitive critical injuries the costs per trip would sky rocket. These birds have to fly in order to pay the bills so the low acuity flights are actually subsidizing the critical flights.

    Hard question: How can we know what percentage of patients had a positive change in their outcome because they flew in a bird instead of being ground pounded?

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    1. With regards to cost-effectiveness...obviously, the more a helicopter flies the less each trip costs. However, I was speaking to HEMS' cost-effectiveness to society or the individual patient, not the company operating it. If a significantly expensive transport doesn't result in the patient living when they would not have otherwise, or significantly reduce morbidity, how cost-effective is it from that perspective? An additional downfall of more flights is that there is an increased probability of a helicopter not being readily available when needed for those truly critical injuries.

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    2. And your question is indeed a hard one :) I think that, ideally, we'd all like to see some data comparing air vs. ground EMS measuring things like time spent in hospital, mortality, adverse events, time spent in rehab, and total cost of healthcare. That might give us some insight into the actual benefit of helicopter transport, and types of patients who truly benefit from that resource.

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  2. It says on your blog that you are a plummer? Have you worked as an ALS provider?

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    1. I'm not sure where you're reading that I'm a plumber...I've worked in EMS since 2003, and as a paramedic since 2007.

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  3. This is an interesting article and a sad symptom of an issue that we in EMS are dealing with all too frequently.

    Where is the evidence to support what we're doing in the field?

    Too often, the answer is that there really isn't any or, even worse, that the evidence tells us that what we're doing is harmful, but we're *still* doing it! If we want to claim the title "Medical Professionals" we have to stop doing that.

    The proliferation of medical helicopters around the state of New Mexico, and presumably a similar proliferation around the country, is emblematic of this mindset. This proliferation is occurring despite the ambiguous evidence of the benefits of HEMS transport of patients. Often, this overuse of HEMS comes at great, and tragic, cost, as it did here in NM just a few days ago.

    We need to do better both for our patients and for ourselves.

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  4. All three onboard CareFlight 5 are very good friends of mine. They where doing what they lived for... They where responding to a call for aide. The same way they had so many times before. I agree with your statement that the cost is high when there is an incident. I ask that you honor the memories of Jamie, Rebecca and David by not using them to try to drive a point about the "over use of HEMS". Their lives are worth far more that can be imagined. I will not take up the argument for or against at this time. But, I ask that you not pass a judgement until you have walked a mile or more in my shoes. And by the way I have been in the EMS field since 1989. I have seen the best and the worst of it. Today I mourn the loss of three wonderful caring souls who have been called to Heaven.

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  5. It's not disrespectful to the lost flight crews to address this topic. The tragedy that they are no longer among us should drive us to want to address this issue, not sweep it under the carpet. We quite possibly just sacraficed your frinds on the alter of EMS bad judgement. It's perfectly acceptable to mourn the loss of your friends. It's also perfectly acceptable to get a little pissed off and start demanding a better reason for why we keep doing this year after year.

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