Background
The title of this article could very easily be “Emergency Medical Technicians: Not Just Ambulance Drivers Anymore” or even “The Emergency Department: Not Just An ‘ER’ Anymore.” The point is that the face of healthcare in New York is changing and we have had to adapt in a way that results in the most appropriate care for our patients. Fiscal and staffing issues are among the concerns that have lead to consolidation of health care services in many areas of the state. The result is that every hospital does not have access to every service at all times. Patients with specialty needs may need to be transported to distant centers. Patients with certain time sensitive conditions may benefit from primary transport to the hospital offering definitive treatment rather than the previous common practice of transport to the closest hospital with secondary transfer. Depending upon the immediate needs of the patient, the level of care available within the ground EMS system, the distance to be traveled and the local resources, helicopter emergency medical services (HEMS) may be a consideration in the pre-hospital management and transport of such patients. It is very clear that cooperative preplanning is imperative in determining the most appropriate indications for HEMS utilization in a given locale. This article will review the progression of HEMS over the years and outline what we are doing in New York State to assure appropriate utilization of this valuable resource.

History
The first reported air transport of a patient was in 1915 by a French pilot who evacuated an injured Serb in an unmodified fighter plane. Through progressive conflicts, airplane evacuation of injured and ill patients became more prominent. The first medical use of a helicopter was seen in Burma in 1944 and the first large scale medical evacuation was in Korea by Sikorsky helicopters outfitted with outboard stretchers. The UH-1H (commonly known as the “Huey”) was central to medical care in Vietnam and was credited with a reduction in morbidity and mortality of injured soldiers. This wartime utilization of helicopters for patient transport was not lost on the American Public and in the early 1970’s federally funded pilot projects began looking at the feasibility of helicopter use in the U.S. The need for integration of such services into the existing ground EMS systems was recognized.

Early HEMS services began as components of civilian law enforcement and fire agencies that occasionally would provide medical transport when they were not committed to their primary duties. A few notable services pursued dedicated air medical programs, namely the Maryland State Police and the LA County Fire Department. Other HEMS services began as hospital based programs that were either free standing or involved a lease agreement for an aircraft through a vendor. The first of these programs was Flight For Life in Denver, CO in 1972.

In the beginning of HEMS use in the U.S., trauma was the main indication for utilization of this rapid transport service. In the early 1980’s the role of HEMS expanded to include transport of patients who had specialty medical needs although the majority of transports were still for injured persons in need of specialty trauma care. In the mid-1980’s there was a federally lead focus on safety and cost effectiveness of this expensive and limited resource. Significant changes were made in regulations affecting the operation of these services that were hoped to improve safety in an industry that seemed to have more than its share of aviation accidents.

Currently, more than 30 years after HEMS began in the U.S., there are over 500 bases and over 650 helicopters in use.1 It is estimated that over three hundred thousand patients are transported annually. As the needs of the patients being transported have become more advanced, the practice of the flight crews has expanded. In many services, the capabilities of air medical teams essentially bring resources normally only available in a hospital to the patient wherever they are. The time has come to think about HEMS as a sophisticated level of care rather than simply rapid transport. This level of care and rapid means of transport lends itself to the care of many patients who need services only available at a distant facility and who may have a need for critical care during transport.

Ground EMS services have undergone evolution in a manner similar to that of HEMS. The origins also lie in wartime experiences and changes have occurred over the years in response to the needs of the medical community. Currently there are many different system models and provider levels across the state. In response to the need for transport of critically ill patients, the EMS system has responded by creating a new advanced practice for paramedics that is specific to the needs of the locale. These “paramedics with additional training” or sometimes labeled “Specialty Care Paramedics” have advanced training and protocols that govern the care they provide in a wide variety of circumstances.

The evolution of both ground based and air medical transport services have not occurred in isolation. A team approach that encourages the integration of the ground and air services is best when attempting to assure the most appropriate means of care and transport for individual patients within a system. Education of all providers and of users of the system is paramount in order to assure the most appropriate decisions are made regarding utilization of each service. Guidelines governing utilization of HEMS must be defined and clearly communicated. Quality assurance and retrospective review of such decisions is key to a successful system.

Helicopter Utilization
Despite the immense growth in the industry over the last decade, HEMS remains a relatively scarce resource in most areas of New York. Additionally, the operating costs of a helicopter far exceed those of a ground based unit. For these reasons, it is important to limit the utilization of these HEMS to those situations which have demonstrated benefit. A recent position paper of the National Association of EMS Physicians and the Air Medical Physicians Association describes these situations in detail, focusing mainly on patients with suspected severe traumatic injuries for scene helicopter response. The use of HEMS for nontraumatic issues is not as well researched but it is acknowledged that logistical considerations may make such use appropriate.2

In support of utilization of HEMS for patients with specific time sensitive, nontraumatic conditions are two position papers from the Air Medical Physicians Association.3, 4 These papers describe the benefits of HEMS utilization for patients suffering from an acute stroke or an acute coronary syndrome. In both cases, the most advanced care for these conditions is often only available at tertiary care centers. State designation of Stroke Centers is underway currently across New York and a similar process may likely be forthcoming in the near future for hospitals offering definitive care for patients with ST elevation myocardial infarctions. Similar to our practice for trauma, if we encourage primary transport of patients with these and other extremely time sensitive conditions to a center that can provide definitive management, patients may derive benefit. While this practice is not well described in the literature, benefits can easily be seen in individual cases where the time to treatment is significantly decreased. More research is clearly indicated as the medical community moves more toward regionalization of these specialized services.

Many HEMS teams bring several resources to patients. These can be simply thought of as “Time, Terrain and Talent”. The rapid means of transport offered by a helicopter can decrease “time” to definitive care and decrease the total time spent out of the hospital. Primary transport to the most appropriate hospital is possible rather than stabilization at a community hospital and secondary transport, a practice that decreases the time to definitive management of many conditions. The ability of an aircraft to overcome many environmental obstacles (waterways, mountains, etc) and overfly traffic gridlock offers some benefit related to “terrain”. The advanced practice of many HEMS teams offers a “talent” to critically ill and injured patients prior to and during transport. Often, the HEMS team consists of advanced practice paramedics, critical care nurses, respiratory therapists and in some cases physicians who receive training specifically geared toward caring for persons in crisis. These highly skilled teams have access to sophisticated equipment and medical technologies not often available to ground EMS or even to physicians in community hospitals. Each of these advantages of HEMS utilization has the potential to benefit patients with many types of illness or injury.

Triage
The most recent estimates indicate that more than 300,000 patients are transported by helicopter every year in the U.S. A medical helicopter takes off every 90 seconds in this country responding to an emergency.5 Despite this, we continue to see patients arrive by ground services who seem to have met criteria for HEMS utilization and may have derived benefit from such a service. The density of HEMS bases is vastly different around the country.1 In some areas of New York, when a helicopter is busy on a flight, the next closest aircraft can be a great distance away. It is therefore critical that we assure appropriate triage of patients to this limited resource.

While the triage process should screen for the most seriously ill/injured people, it must assume a certain over triage rate in order to capture the greatest number of appropriate patients. Any triage criteria must account for the limited time the ground EMS providers have with which to make a decision and use parameters that are easily assessed by even basic providers, as they are often the first on the scene of an incident. It is intuitively obvious that if HEMS is to offer benefit, they must be requested as early as possible. Therefore, guidelines must be written that allow for the earliest arriving personnel to an incident to recognize the need and have the authority to request HEMS. Some areas have written protocols that allow HEMS standby requests by the communication specialist at the time of incident dispatch based upon a priority dispatch system. This practice has been shown to result in helicopter transport of higher acuity patients in some systems. 6

While development of helicopter utilization criteria and guidelines can be useful for a system, individual patient decisions must be made based upon certain practical considerations. Situation specific issues that must be taken into consideration when the decision for HEMS utilization is made include the following: the individual’s suspected diagnosis and how time sensitive it is thought to be; the availability of definitive care at local hospitals; the distance to the most appropriate hospital and the traffic and geography associated with transport there; availability of ground based vehicles and appropriate level of care for the patient’s condition; weather patterns; and cost.

Considerations for HEMS utilization in the trauma patient should address physiologic and anatomic factors as well as the distance to the closest trauma center. The American College of Surgeons Committee On Trauma advocates that any seriously injured patient be primarily treated at a trauma center.7 HEMS response to the scene where such patients originate can facilitate this goal when trauma centers are somewhat distant. Additionally, HEMS crews can bring needed services, such as advanced airway techniques, to the patient more quickly than they might receive even with ground transport to the closest facility. Protocols that help EMS providers identify which patients have injuries that warrant transport to a trauma center should be based upon outcome data that is ideally obtained locally. New York has recently revised the trauma triage guidelines utilized by EMS providers based upon local trauma registry data. The patients meeting criteria for transport to a trauma center that may benefit from HEMS transport is a subset of the entire group. The “time, terrain and talent” guidelines can be utilized on a patient by patient basis in the absence of more formal guidelines for HEMS utilization.

The traditional use of HEMS for non-trauma patients has been in the interfacility transport arena. With the consolidation of services and designation process underway in New York for certain specialty services, the time may have come for the medical community to examine the utilization of HEMS for the primary transport of ill patients from a scene to the hospital that has the ability to deliver definitive care. Non-trauma considerations for helicopter utilization might include a variety of medical or surgical conditions in which rapid transport, distant transport, or an advanced level of care on scene might be beneficial.

In discussing considerations for HEMS utilization for transport of patients from a scene, it is also important to identify situations in which such a service would be contraindicated. It would serve no benefit to transport a terminally ill patient with no correctable medical problem by HEMS. An example of this patient type would be the nonhypothermic patient in cardiac arrest without spontaneous return of circulation after initial maneuvers performed by ground providers. While patients with high risk pregnancies may realize benefits by the advanced care and rapid transport offered through HEMS, if delivery is expected during transport, a helicopter may not be the most appropriate mode of transport given the space limitations when compared to some other transport vehicles. Clearly if this patient were in a medical facility, consideration should be had toward delivery in that institution prior to transport, in accordance with federal regulation.8 Lastly, the patient who is prone to psychotic or violent behavior who cannot be adequately controlled with appropriate sedation and/or restraint should not be placed in a helicopter. Uncontrolled outbursts by a patient may create an unsafe environment in the helicopter and should not be allowed to occur.

Utilization Review
As with many other resources we utilize in our practice in emergency medicine, the utilization of HEMS for scene response as well as for interfacility transport must be reviewed for appropriateness. It is important that this utilization review be continuous and thorough, though it is likely best accomplished in a retrospective manner. Prospective screening of HEMS requests to the scene of an incident is difficult and fraught with dangers given the limited information and time constraints that are often present in such situations. Retrospective review of utilization by designated groups can identify and address problematic trends in under or over utilization. Once these issues are identified, education can be provided to the parties involved. Such feedback is crucial to assure the most effective practice. Additionally, the noting of trends can steer the development of guidelines and protocols where appropriate.

New York State HEMS Utilization Criteria
In the past, the criteria for HEMS utilization in New York State has been quite varied from one region to another. Some regions have written extensive protocols to be followed for requesting HEMS to the scene of an emergency. Others have chosen not to be quite so formal, relying upon memos or simply allowing common practice to guide utilization trends. The State Emergency Medical Advisory Committee (SEMAC) recognized the need for a statewide standard to help guide the practice of EMS providers across the state with regard to helicopter utilization. At the March 29, 2005 meeting, this was approved in the form of a guideline that outlines the factors that come into play when considering the use of HEMS at the scene of an incident. This document suggests to regions how to govern the scene response of HEMS in a variety of circumstances. Who can request a HEMS response, when such requests should be considered and when an aircraft should be cancelled are outlined in this guideline. Situational criteria as well as specific patient conditions in regards to major trauma patients, critical burn patients, and patients with an acute stroke or ST elevation myocardial infarction are addressed. When specific patient criteria are not met, yet a ground provider believes that a patient may benefit from HEMS utilization in accordance with the general concept of “time, terrain, talent”, medical control is strongly encouraged to assist in the decision to utilize HEMS.

It was clearly recognized that specific local differences do exist and that regions should utilize this document as a guideline and adjust their practice appropriately. The intention of the SEMAC is simply to provide guidance that might serve to standardize the utilization of HEMS across the state. It is hoped that this will improve the utilization of HEMS in those regions that might not have had written standards and perhaps draw attention to the need for continuous review of such standards in regions in which they existed.

These guidelines were written with an attempt to maximize appropriate utilization while minimizing the overtriage that may be seen without the use of such a plan. The specific criteria included in the guideline as approved reflect national standards, available literature, New York State Protocols as well as standard practice in the state.2-4,9 It is very clear that any change in practice regarding HEMS utilization must not be made in isolation of any party. Ground EMS services, HEMS services, regional EMS authorities as well as representatives from receiving hospitals must participate in a cooperative discussion regarding what would be most appropriate for their locale. As Emergency Physicians, we will likely be asked to participate in such a discussion.

Once a conclusion is reached regarding a region’s needs, it is important to assure ongoing review. Utilization must be tracked and changes in the make up of the regional resources must be taken into consideration in the future. It is such changes that have lead us to discuss this expansion of the use of HEMS from it’s traditional role as a rapid means of transport for the injured patients from the scene of an accident. Continued attention must be paid to this important issue and outcome based research is imperative. The air medical and emergency medical community must be committed to this effort so that we can most effectively utilize this limited and expensive resource to provide the most good to our patients.

Note: As of the writing of this article, the New York State Helicopter EMS Utilization Criteria has yet to be released. Upon its release it will be found on the NYS Department of Health Website under the Bureau of EMS section on SEMAC Advisories.10

References:
1. Atlas & Database of Air Medical Services (ADAMS)
Jointly Sponsored by the Center for Transportation Injury Research (CenTIR) and AAMS. 10/2004www.ADAMSairmed.org
2. Thomson, TP; Thomas SH. Guidelines for Air Medical Dispatch. Prehospital Emergency Care. April/June 2003. Volume 7/Number 2. pp265-271
3. Hutton, K; Sand C. Appropriateness of Medical Transport and Access to Care in Acute Stroke Syndromes: Position Statement of the Air Medical Physician Association. And Association of Air Medical Services. October 2004. www.ampa.org
4. Position Paper Task Force of the Air Medical Physicians Association. Appropriateness of Air Medical Transport in Acute Coronary Syndromes. November 2001. www.ampa.org
5. AAMS Brief-Part One: Our Commitment to Safety. www.aams.org
6. Funk DL, Emerson C. Automatic helicopter standby policy for seriously injured patients. Air Med J. 2003 Jul-Aug;22(4):32-5.
7. Resources for Optimal Care of the Injured Patient: 1999 American College of Surgeons Committee on Trauma. 1998.
8. Bitterman RA. Providing Emergency Care Under Federal Law: EMTALA. American College of Emergency Physicians, Dallas, Texas. 2000.
9. AAMS, ASTNA, NFPA, AMPA, NEMSPA, NAACS. 2004 Guidelines for Air Medical Crew Education. Module 13.
10. http://www.health.state.ny.us/nysdoh/ems/policy/policy.htm