What is the main benefit of helicopter EMS?

Most everyone would say the time it cuts in getting patients to an appropriate level of care. Indeed, there are numerous studies that show that time-saving transport is beneficial.

A recent survey of more than 250,000 scene trauma transports found that HEMS reduced mortality by 22 percent over ground transports. And data from the University of Wisconsin finds that HEMS provides an average patient transport time savings of 10 minutes (urban transfers) to 45 minutes (rural transfers) compared to ground transport.

But is time the only factor at work here? Not according to a 2012 study prepared for the Oklahoma State Department of Health. That study contends that HEMS medical crew expertise is often superior to that available in ground ambulances — especially when it comes to airway management. The Oklahoma study noted that:

"In some cases the time benefit is manifest in allowing patients to receive therapy that cannot be administered outside certain time windows. In other cases time benefit is simply a matter of expeditiously getting the sickest patients to the centers best suited to care for them.

"If time is not always responsible for HEMS' outcomes benefit, what other variables come into play? The first, already mentioned with respect to trauma and golden-hour interventions, is crew expertise. While obviously not always the case, it is quite frequently true that HEMS crews have considerably more experience and expertise with critically ill and injured patients than providers available at referring agencies. This elevation in medical care can be the case regardless of whether the mission type is a scene run or interfacility transport."

The study goes on to point out, "Data focusing on patients with severe trauma (e.g. head injury) suggests that HEMS crews' early provisions of ALS-level airway and hemodynamic support (i.e. intravenous access and fluid management) are the mechanism for improved overall outcome and better neurological function."

The latter particularly holds true in rural areas, where ground ambulances are staffed by community volunteers as opposed to full-time medical professionals according to state data cited in the study.

"In Nebraska, for instance, the HEMS-associated one-third mortality reduction for severely injured patients has been ascribed to much higher rates of airway management (80 percent in HEMS, versus 10 percent in ground EMS) and even intravenous access placement (100 percent in HEMS, versus 50 percent in ground EMS)," the study stated. "Assuring optimal prehospital care for all Oklahomans will mean acknowledgment that, for patients in some isolated areas, HEMS represents the best mechanism to get needed advanced therapy to the scene."

Yes, HEMS transport saves time, but rather than the hour, it's often the crew that is really golden.