Despite the rising number of HEMS-related deaths and injuries, only recently has there has been any organized effort to address the problem from the aviation end. Unfortunately, very little has been done to discourage the widespread inappropriate utilization of this procedure. Instead of attempting to limit HEMS usage, many operators continue to focus on increased utilization and expansion—primarily into already saturated markets.
Between 1980 and 2008 there were 264 total HEMS-related fatalities (223 crew members, 34 patients, and 5 other). The year 2008 was the worse year on record with 15 HEMS accidents and 29 fatalities. This resulted in three days of hearings by the National Transportation Safety Board (NTSB). In September of 2009 the NTSB published numerous recommendations aimed at making HEMS safer. Among these recommendations were improved pilot training, additional safety instrumentation and technology on medical helicopters, establishment of national usage guidelines, and annual reporting of the number of hours flown and patients transported. In a significant deviation from any precedent, the NTSB also recommended that the Centers for Medicare and Medicaid Services (CMS) tie HEMS reimbursement to the level of HEMS transport safety provided.
There has been an explosive expansion in the United States HEMS fleet in the last decade. In fact, the fleet has more than tripled to almost 900 helicopters in a little over eight years. Interestingly, there are more medical helicopters in either the Dallas/Fort Worth or Phoenix metropolitan areas than found in all of Canada. In addition, there has also been a transition in HEMS from a hospital-based model to a community-based, for-profit model. The largest area of expansion has been with the interfacility transport of patients—often from one emergency department to another. This uncontrolled, unregulated growth has largely been industry-driven with little scientific support for the practice. A HEMS vendor can essentially place a helicopter base wherever they deem necessary or profitable. Wisconsin, with 65,000 square miles and a population of 5.6 million, has 11 medical helicopters. Most EMS professionals in the state would agree that there is no pressing need for additional helicopters. The state of Missouri, with a very comparable size, population and demographics, has 33 medical helicopters. Why the 300% difference? There are several reasons. Medical necessity is not one of them.
Emergency physicians possess incredible control over the HEMS industry. We are responsible for initiating the majority of the interfacility transfers. We also provide medical control for most HEMS programs and for the ground EMS units that request the helicopters to accident scenes. Thus, we have the ultimate authority as to whether a patent being transferred should go by ground or air. Unfortunately, there has been little education and few guidelines to aid emergency physicians in this decision making process.
In 2009, the American College of Emergency Physicians (ACEP) published a policy statement entitled Appropriate Utilization of Air Medical Transport in the Out-of-Hospital Setting. This policy takes a commonsense and evidence-based approach to out-of-hospital HEMS usage. The policy states: Appropriate reasons to use an air medical helicopter in the out-of-hospital setting include:
(1) Patient has a significant potential to require high-level life support available from an air medical helicopter, which is not available by ground transport.
(2) Patient has a significant potential to require a time-critical intervention and an air medical helicopter will deliver the patient to an appropriate facility faster than ground transport.
(3) Patient is located in a geographically isolated area, which would make ground transport impossible or greatly delayed.
(4) Local EMS resources are exceeded
In addition to safety concerns, the cost of HEMS transport can be more than ten to fifteen times that of ground transport. It is not uncommon for HEMS transport charges to exceed $15,000 per trip. The ACEP criteria can provide some direction in determining which patients may benefit from interfacility transport by HEMS.
The benefit of HEMS over ground EMS is speed (and in some cases the level of care provided). Some patients require care that cannot be provided by standard ground ambulance crews. However, in many cases, these patients can be safely transported by ground ambulances using critical care paramedic or critical care nursing crews if their condition doesn’t warrant more rapid transportation. A British Columbia study of almost 2,000 interfacility transports of ICU patients found that HEMS transport was not associated with improved overall mortality when compared to ground transport. A University of Wisconsin—Madison study found HEMS interfacility transport faster than ground transport, but suggested that stable patients should go by ground EMS (GEMS) if timely service is available. If the patient does not have a time-sensitive condition, then consideration should be given to using a ground critical care transport service.
Although HEMS transport is always considered more rapid than ground transport, ground transport is typically faster at distances of less than 45 miles. In a California study, researchers found that ground ambulances were always faster at distances of less than 10 miles. At distances greater than 10 miles, HEMS was faster than ground EMS if simultaneously dispatched (which rarely happens). If HEMS was not dispatched simultaneously with ground EMS (the more common scenario), ground EMS was faster at distances of less than 45 miles. An Australasian College of Emergency Physicians policy states that patients less than 30 minutes by road from a hospital do not benefit from HEMS transport. At distances greater than 300 kilometers (or when HEMS flight time exceeds one hour), fixed-wing air transport is preferred. The guidelines in the United Kingdom are similar.
Thus, if the patient is more than 45 miles from the receiving hospital, the question becomes whether or not the patient has a time-sensitive condition. Here the policy is fairly straightforward. Certainly STEMI patients and stroke patients should be transported by HEMS if HEMS transport will deliver them to definitive care within an interventional window when ground EMS may not. In trauma, the role is less clear. In fact, few trauma patients require truly lifesaving surgery. In a 10-year study of all trauma patients brought to a Santa Clara (CA) trauma center, only 1.8% underwent surgery for a life threatening condition. In a 10-year study, researchers in Los Angeles were unable to identify improved survival for trauma patients transported by HEMS (although they felt severely injured patients might benefit from shorter prehospital times).
Despite a lack of evidence demonstrating improved morbidity and mortality with interfacility HEMS transports, it seems intuitive that there is a subset of critically-ill medical/surgical patents where total out of hospital time should be limited. However, additional research is needed to determine which of these patients should go by HEMS and which can safely go by ground EMS.
HEMS transport is truly a medical procedure and requires evidence-informed decision-making. With HEMS, the patient’s condition and need for definitive care should be the primary determinant for utilization. While additional research is needed, new strategies can serve as an initial guide for limiting HEMS utilization. One such strategy is detailed in Figure 1 and based upon the ACEP policy discussed earlier. Determining whether a patient has a time-critical condition is often more complex. Figure 2 details the decision scheme for determining whether a patient has a time-critical condition that might benefit from HEMS transport. Regardless, the emergency physician should always err on the side of caution.
As Emergency Physicians, we hold the reins of the HEMS industry. We can allow it to continue its current unregulated and uncontrolled trajectory or we can initiate a new era of appropriate utilization based on evidence based medicine and solid scientific research. The decision is uniquely ours.
It is not an uncommon practice for HEMS crews to ask emergency physicians (EPs) to sign a Certificate of Medical Necessity for helicopter transport. This can occur at either the transferring or receiving facility. As with many things placed before us in the ED, we often sign these without a second thought. However, with increased scrutiny on HEMS costs, utilization, and safety, EPs should avoid reflexively signing these forms. To avoid potential liability, it is essential to first assure that the patient truly has an emergent, time-sensitive condition or requires a level of care clearly unavailable by ground EMS and that HEMS transport is truly necessary. Transferring patients by HEMS because of ED crowding or convenience will be subject to increasing scrutiny. Also, EPs who serve as medical directors of HEMS and ground EMS operations are occasionally asked to retrospectively sign Certificates of Medical Necessity for HEMS transport. These too can be problematic if you were not involved in actual care of the patient in question or do not have first-hand knowledge of the circumstances of the transfer. Remedying the current HEMS crisis starts with EPs carefully reviewing usage and need.
-Bryan Bledsoe, MD
Dr. Abernethy is a clinical assistant professor of emergency medicine at the University of Wisconsin School of Medicine and Public Health and the chief flight physician for UW Med Flight.
Dr. Bledsoe is a clinical professor of emergency medicine at the University of Nevada School of Medicine.
Dr. Carrison is professor and chair of emergency medicine at the University of Nevada School of Medicine.
American College of Emergency Physicians. Appropriate Utilization of Air Medical Transport in the Out-of-Hospital Setting. [Available at: http://www.acep.org/practres.aspx?id=29116]
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