The benefits of HEMS – more than just statistics!

As demonstrated by the previous post, studies that show a benefit for HEMS receive significant exposure within the medical and prehospital community. Due to the nature of the work, often relatively short times providing care to patients, and heterogeneity of patient/pathology/environment, benefits in terms of statistically significant improved patient outcomes are difficult to demonstrate.

In this post, I thought I’d outline some of the non-measurable benefits that have resulted from the advent of the Auckland HEMS (specifically by combining the existing paramedic/crewman team with a hospital-based doctor).

1) Improved understanding influencing ED care

Those of us who have ventured into the prehospital environment have gained a new understanding of the specific challenges involved, including those around the interface between the prehospital and hospital environment. With our newfound experience and the guidance of our paramedic colleagues from St John and ARHT, the way patients are handed over by prehospital staff and received by ED staff has evolved. This is best explained in this post, which contains a video demonstrating an effective handover template and use of a whiteboard for significantly unwell patients. As an ED doctor receiving patients and leading a resus team , this sort of process feels like  significant improvement in patient care – even if proving it with statistics would be just about impossible!


Auckland ED ambulance bay

2) More communication and teamwork

While working in HEMS, we have built relationships with pilots, crewmen, paramedics, and other ARHT employees. What has been surprising however is the extent to which communication has changed between ED doctors (not just the HEMS doctor team) and our St John paramedic colleagues who are NOT directly involved with the Westpac Helicopter. In addition to evolved handovers as discussed above, there seems to be a lot more dialogue between paramedics and doctors in our ED. We are fielding more questions and requests for feedback about patients that are delivered to us, more clinical queries and requests for information in general, requests for paramedics to attend ED mortality/morbidity reviews where appropriate. Speaking for myself, this a two way process – with more of an understanding of how the prehospital setting works, I can now request additional information from paramedics with the aim of improving the care I deliver.

Recently, the benefits of more communication and dialogue were demonstrated to me when two St John paramedics who had delivered a critically ill trauma patient became active resus team members a considerable time after their handover. I was leading a team dealing with severe haemorrhagic shock, a massive transfusion requirement, extremely poor vascular access, a reduced LOC, and a predicted difficult airway. The patient also had multiple long bone fractures, and with all the doctors in my team tied up dealing with the other issues, the two paramedics rapidly and effectively splinted the fractures for me. (Thanks guys – and feel free to leave your Sager traction splint in the ED annnnny time you like…!) I am unsure whether this sort of collaboration would have occurred prior to the ‘cultural change’ that seems to have arrived since the advent of HEMS, but now it feels like there are no barriers in place.

A valuable addition to the ED team..

A valuable addition to the ED team..

3) Active safety management

Placing hospital-based doctors in an aeromedical setting exposes them to the systems required in aviation, including those regarding safety management (watch this video if you haven’t already!) Medicine is traditionally some years behind aviation with regards to active safety management, and while aviation systems cannot be directly be ported directly to medicine (this, plus the process of moving on from aviation learnings into ED-relevant material is discussed on Resus Room Management – a great site that is well worth a look), there is much we can learn.

The involvement of the helicopter crewman in the medical resuscitation team lent itself well to checklist use (crewman have a lot of experience with checklists!), and the Auckland HEMS RSI checklist was the end result. The familiarity with checklists has started another culture change in our ED, and people are starting to realise their value. While Auckland ED has not yet adopted a formal RSI checklist, versions are already being used in our resus rooms, and have the potential to significantly improve the safety of our advanced airway management.

Involvement in HEMS has also allowed the medical team to gain experience with an online safety management system. ARHT uses Air Maestro, which is now being used by the trust to cover medical as well as aviation issues (many thanks to Armin Egli and Paul Robinson for sorting this one out!). While introducing something like this to ED would be a difficult undertaking, gaining experience with it through HEMS allows us to explore the medical uses while seeing in real-time how it improves the safety of aviation operations. Food for thought…

The comments above represent my thoughts about some of the non-measurable benefits of the Auckland HEMS trial. I’d love to hear your thoughts, please post comments below if you wish.


The benefits of HEMS – more evidence!

This post was prompted by two new studies about the benefits of HEMS. For those of you with short attention spans, I’ll give a one-liner on each study then describe them more thoroughly later on.

  1. U.S database study: among severely injured trauma patients (Injury Severity Score >16), HEMS is associated with improved survival rates 
  2. Dutch database study: Reduced mortality among polytrauma patients especially those with abnormal vital signs

The debate surrounding the benefit of patient-oriented outcomes for HEMS is nothing new.  In much of the world, HEMS (helicopter emergency medical services) includes physicians on board the helicopter though in North America often HEMS clinicians are advanced care paramedics. In each country, different models exist and as a result extrapolating findings to our setting is difficult.

One of our BK's that we fly at ARHT

One of our BK’s that we fly at ARHT

It’s easy to imagine that that HEMS (with or without a physician on board) benefits our patients. We bring highly trained clinicians to a scene where we can perform advanced interventions and then rapidly transport the patient to hospital for definitive care. However, studies have demonstrated variable results regarding patient outcomes with HEMS. These differences are undoubtedly affected by the variability amongst HEMS systems around the world. Each HEMS group operates with different thresholds for activation, variable relationships with the local land EMS and then there are a range of geographic and patient characteristics that will affect patient outcomes.

I mentioned above two recent studies that provide additional evidence into the benefits of HEMS. I’ll focus on the Dutch study from the European Journal of Emergency Medicine primarily. They included a consecutive cohort of trauma patients that either HEMS or land EMS responded. It’s not  They used some fancy statistics to calculate lives saved due to HEMS response. It would have been nice to have a more detailed description about their setting as it would allow for more robust comparisons to other centres. It should be noted they had <5% penetrating trauma in their population. It’s unclear how this impacts the statistics but likely critically ill patients who suffered penetrating trauma should be transported to hospital quickly since operative management is likely to be required. They also intubated a large number of their patients when HEMS was on scene (58%). This number was quite surprising. In our setting, we would intubate <10%. Again, whether they have an standard operating procedure or set of criteria for intubation – it would have been good for some discussion about this.

They had fairly reasonable scene times as well. While I don’t think scene times are as important as sometimes they’re made to be especially when necessary interventions are being performed, they at least didn’t spend hours on scene! Interestingly, when we compare the EMS vs. HEMS pre-hospital time there was a 7min difference (42min vs 49min). This is almost entirely accounted for by the extra 7 min that HEMS spends on scene. The authors describe short transport times which suggests that if there truly is a HEMS survival advantage then this isn’t the result of faster transport.

In the U.S study, which has a very different EMS system, they found survival benefit among the most seriously injured trauma patients. I believe there weren’t physicians part of the U.S HEMS model but they probably had advanced care paramedics. Unfortunately the study doesn’t describe the system well. Nonetheless, again using some statistics to account for injury severity, HEMS in the U.S appears to benefit sick patients with altered physiology. It is challenging to interpret U.S data as there’s considerable heterogeneity and financial drivers for HEMS use.

Ultimately we need more prospective data that isn’t fraught with the challenges of using retrospective data – each of these above studies suffer from these limitations. However, there is an emerging trend that HEMS benefits severely injured patients and more importantly, this could be independent of the transport time benefits. This is growing evidence that HEMS is not just an expensive, fast taxi service. Instead, improved patient outcomes may be the result of better clinical expertise brought to the scene.