Unneeded use of helicopter emergency medical services (HEMS) air transport is a problem around the world. This scarce and valuable resource tends to be over-utilized, resulting in unnecessary costs to patients and the health care system in general. Unfortunately, good and objective criteria for HEMS transport have been hard to come by.
A group at the University of Pittsburgh published a study earlier this year, developing an objective scoring system based on a huge dataset from the National Trauma Databank. They used a portion of the data to develop a model, and the remainder to test it. They developed the AMPT, which identified patients that showed a survival benefit with helicopter transport:
For this AAST abstract, they sought to validate the scoring system using an entirely different database, the Pennsylvania Trauma Systems Foundation registry. They used 14 years of data, and reviewed nearly a quarter million records. Once again, the authors were looking at in-hospital survival.
Here are the factoids:
- 20% of patients were transported by air
- But only 11% were predicted to benefit by using AMPT
- For patients with an AMPT score < 2, transport by air did not increase survival
- For patients who had an AMPT score >2 and were actually transported by air, survival was improved by 31% (!)
Bottom line: It looks like the AMPT score is a good predictor of improved survival for patients transported by air. But wait, it’s not that cut and dried. These statistics are based on populations; they cannot predict exactly which individual patient will benefit. What about those patients who actually died? Perhaps if they had gotten to the hospital a little faster, they would have done better? This is certainly a nice new tool to use in the decision-making process, but it can’t be the only one.
- The air medical prehospital triage score: external validation supports ability to identify injured patients that would benefit from helicopter transport. AAST 2016, Paper #23.
- Development and validation of the air medical prehospital triage score for helicopter transport of trauma patients. Ann Surg 264(2):378-385, 2016.
The use of helicopters for transporting injured patients dates back to World War II. Thirty years later, this concept was translated into civilian practice. Today, there are hundreds of helicopter EMS (HEMS) services across the US, and thousands world-wide. Unfortunately, the indications for using this service are not strictly defined, and it is very expensive compared to ground EMS transport. In the US alone, there are over 400,000 HEMS transports per year. This creates the opportunity for use in patients who are not seriously injured, as well as the potential for wasted resources.
The University of Arizona at Tucson examined 6 years of transport data to their center, by both ground and air. They were interested to see if they could identify a group of HEMS-transported patients that could have safely and more reasonably been transported by ground ambulance. They defined this group of “minimally injured” as having an injury severity score (ISS) of 5 or less.
Here are the factoids:
- A total of 5,202 patients were transported, 19% by air and 77% by ground
- Overall, the hospital length of stay was significantly longer for HEMS patients (3 vs 2 days), as was ICU length of stay (2 vs 1 days) [Hmm..]
- ISS was significantly higher in the HEMS group as well (9 vs 5) [Hmmmmm…]
- There was [of course] no difference in mortality between the two groups
- By their definition, 28% of HEMS patients were minimally injured, compared to 39% of ground transfers
- The average charge for a HEMS transport was $18,000
Bottom line: This is another paper that just doesn’t deliver on what it’s title suggests. But this one is an underestimation of the result, not an overestimation, for once. From personal experience, I see lots of examples of patients who don’t need air transport but get it anyway. But if you dive more deeply into the data in this paper, you can see why it’s just not good enough. Sure, they’ve got a lot of patients. But if you look at the clinical reality of the numbers, none of the patients were really that sick. The maximum ISS in the HEMS group was 17! The GCS for every patient in the study was 14 or 15. The maximum hospital LOS was 7 days. And the clinical significance of a 3 day vs a 2 day hospital stay is negligible.
These were just not very sick patients. It looks to me like none of their patients needed HEMS transport, other than for extreme distance issues. The authors needed to set a better definition of minimally injured patients, and if they had, they would have found that most of their HEMS transfers could have been shifted to ground ambulance.
This paper really points out (more than the authors anticipated) the potential resources being wasted. There are already some suggested rules for optimal use of HEMS. But unfortunately, we tend to ignore them! It’s time to start a concerted effort to more wisely use this valuable and expensive resource.
Reference: Overuse of helicopter transport in the minimally injured: a health care system problem that should be corrected. J Trauma 78(3): 510-515, 2015.
Yesterday, I wrote about the (unclear) benefits of helicopter EMS transports. Today, I’ll cover the risks. The number of medical helicopters in the US has grown dramatically since 2002.
As can be expected, the number of mishaps should go up as well.
Although it looks like the fatal and injury accidents peaked and then declined, it does not look as good when compared to the rest of the aviation industry. Consequently, being on a helicopter EMS (HEMS) crew has become one of the more dangerous professions.
And unfortunately, the numbers have not improved much during the past five years. So what to do? Make it a big PI project. Approach it systematically, analyze the issues, and create some guidelines and protocols for all to follow.
Tomorrow, I’ll review new guidelines for HEMS released by the American College of Surgeons Committee on Trauma.
Reference: Medical helicopter accidents in the United States: a 10 year review. J Trauma 56:1325-1329, 2004.
The use of medical helicopters has grown at an astonishing rate in the 10+ years since Medicare got involved with payment for this service. All high level trauma centers have helicopter landing facilities, and many either own or are a part owner in at least one helicopter EMS service (HEMS).
Here’s a state by state breakdown of the number of medical helicopters:
It’s gotten to the point where the indication for summoning a HEMS service seems to be the presence of a patient to ride on it!
A lot of papers have been published in the past 20 years trying to justify the benefits of using these services. As is the usually case when a lot of papers are published on one subject, most of them are not very good. Lots of studies have been performed to try to justify their use, and most were not successful. The following items have been scrutinized:
- Interfacility transfers
- Pediatric transfers
- Pediatric trauma
- Rural trauma
Most of these papers found little, if any, benefit. The ones that did tended to be published by institutions that owned these services, raising the question of bias. The one thing that was always significantly different was the cost. HEMS costs at least 10 times more that ground EMS transport.
So the benefits are not very clear. What about the risks? I’ll talk about those tomorrow.
Click here to view the interactive state map of medical helicopters. See where your state is with respect to number of ships and services, and how busy they are.
Yesterday, the NTSB released findings from an investigation of a medical flight that crashed in Mosby, Missouri in 2011. I’ve written about distracted driving before, but this is the worst example I’ve seen.
Apparently, the pilot was having a text conversation during the preflight check and missed the fact that the ship was low on fuel. Once enroute, he finally noticed the situation, but proceeded to pick up a patient for transport, planning on a refueling stop enroute to his destination.
But then he got involved in more texting, regarding his dinner plans for that evening. Think about it: texting while flying a helicopter means taking one hand off the collective control. He apparently believed that he did have enough fuel to get to his destination. Unfortunately, the ship, pilot, patient, and two medical personnel crashed a mile from their destination, within sight of the airport.
Teenagers know texting is wrong, but they believe that they know the way to do it safely. New information shows that adults are just as guilty as their children, but they do it anyway. Airline pilots got distracted working on their laptops in the cockpit, and overflew the Minneapolis airport by several hundred miles a few years ago. Everyone is doing it and they know it’s wrong!
Bottom line: There are no easy solutions, and laws are having only limited effect. For situations like this one, the easiest way to deal with it is to expand the team concept in the aircraft. The crew can’t be arbitrarily divided into medical and flight personnel (pilot) anymore. It seems that these days the nurse/medic/docs on board not only need to tend to their patient, but they need to look after the pilot as well. For everyone’s safety!
Reference: Numerous news items on April 9, 2013. See CNN content here.