The team at Auckland HEMS were somewhat surprised to see this story in the media on Monday:
The Auckland HEMS project was originally a two year pilot conducted between Auckland Rescue Helicopter Trust and Auckland District Health Board. Recently a proposal has been signed off to continue the project for another 3 years.
The Auckland Rescue Helicopter Trust has released a press statement following the story above:
Dr Chris Denny, Medical Director of Auckland HEMS and Emergency Medicine Specialist, has the following to say: Click HERE
The report referenced in the TVNZ clip regarding rotary wing medical services in New South Wales is HERE
What do you think is the best staffing model for helicopter emergency medical systems? Feel free to contribute to the discussion using the comments section below.
In Helicopter Emergency Services (HEMS) around the world, winching to critically ill patients is an important aspect for those in patients otherwise inaccessible by road transport.
Most HEMS services have paramedics as the primary medical responders who are winched to patients, however, in some services physicians who are on-board are also winched resulting in a two clinician operation. For a North American (like myself, Andrew Petrosoniak) this idea of physicians on board the helicopter, nevermind winching to patients is completely foreign! But in HEMS operations around the world, this is a reality.
At ARHT we routinely winch highly trained paramedics to patients but less commonly are physicians required to be winched during a job. However, all our physicians are trained and ready depending on our task assignment. I wrote this post after conducting a recent simulation involving a two-clinician stretcher winch. The simulation was designed after discussion with our paramedics and also review of several recently published articles.
The Greater Sydney Area HEMS group, a service with a well-established physician winch program, just published their experience over the past 3 years. They reported 130 missions (8% of total missions) where a physician was winched along with a paramedic. Interestingly, in less than 50% of cases was a physician only intervention performed. Most of these interventions involved the administration of ketamine. If we compare this to our service, our numbers would certainly be different since our paramedics are trained to administer ketamine. Some of the comments & editorials following this publication did focus on this fact. Questions emerged as to the need to winch physicians if most of the requirements involves the administration of ketamine? What could be argued is that frequently involving physicians in winching improves experience levels and potentially reduces risk to the providers – furthermore there could be other important factors for physician presence that I articulate below.
There was a small but important number of other interventions like RSI and orthopedic procedures that required physician expertise. What wasn’t well described was the importance of having two clinicians to treat the patient. In many instances, having two sets of hands and a second set of eyes for patient assessment can be crucial. It’s difficult to formulate any significant conclusions based on this data but it’s important in evaluating the tasking and training necessary to integrate a physician within the winch rescue team.
This data will be helpful for those services who currently or are planning on integrating physicians within their existing winch system. A second paper, which I won’t review, also reports positive outcomes from their winch rescues involving physicians. Finally, the Sydney HEMS group must be commended for describing a bag valve mask failure during a job. We should encourage reporting such as this as it contributes to the culture of safety that is vital for helicopter rescue services.
Based on these papers during a winch of an intubated patient, we conducted a simulation of our protocols for winching intubated patients. Several pictures are included below that were taken during the simulation. This exercise was extremely successful as it combined a review of the evidence with a review of our protocols. Implementing in-situ simulation as a training method offers an excellent opportunity to practice high-risk procedures in our own work environment. We were able to evaluate our experience using an evidence-based approach.
The merits of physician winches during HEMS rescues will be subject to further debate. The data that I outlined above is far from conclusive, however, these publications are important pieces to incorporate into training curricula for other HEMS operations. Our in-situ simulation training is only enhanced by having access to the experiences of others.
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.
- U.S database study: among severely injured trauma patients (Injury Severity Score >16), HEMS is associated with improved survival rates
- 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.
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.