Aviation Medicine in Unique Environments

Thomas F. Clarke

Roy L. DeHart

Nils Erikson

James A. King

Cheryl Lowry

Kenneth A. Williams

Robert Johnson

Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity.

—George S. Patton

No other medical specialty provides its practitioners the opportunities to practice their craft in such a broad array of environments as the aerospace medical professional (AMP). The nature of aviation medicine often leads those who practice it into austere or otherwise challenging environments and situations that in turn have profound effects on their patient and their practice. It is a basic tenet of medicine that the environment plays a significant role in defining the stressors that affect the patient population in the form of the disease and injury threats they face. The environment also affects the responses, both physiologic and behavioral, which individuals may generate to counter those threats. Furthermore, the same environment may profoundly alter the way the aerospace medicine professional practices the art and science. It can place significant limits on the equipment, supplies, and access to expert consultation among other parameters. To succeed, the aerospace medicine professional must anticipate these limitations and prepare to mitigate them. Furthermore, the AMP must find appropriate compromises, which allow him/her to be able to provide the care needed within the overall parameters of the mission at hand.

The opportunities for individual AMPs to work outside of their usual practice environments will continue to increase. We live in a time of frequent population crisis. A rapidly expanding global population increases the likelihood of conflict between groups as they find themselves increasingly in competition for limited resources and opportunities. Additionally, a higher population density increases the odds that any given catastrophic event will affect even larger populations. Furthermore, modern communication technologies mean that events from halfway around the world will quickly become news at home. When political leaders look to who can provide medical care in time of a contingency they will continue, as they have done in the past, to look to AMPs. They will be called upon to care for the aviators and support personnel who provide the airlift necessary to bring resources to bear on acute disasters. In addition, history has shown that AMPs have the training, the experience, and the assets to respond successfully to such crises.

In this chapter, we will discuss general principles of medical practice as they pertain to the preparation and execution of medical support missions to the unique environments one may be called to practice in. We will discuss principles of patient movement during contingencies and further discuss several specific unique environments both to illustrate their particular features and to serve as examples of how basic principles may be applied to diverse environmental challenges.

OPERATIONAL/CONTINGENCY MEDICINE IN THE AUSTERE ENVIRONMENT

In this section, we focus on the principles of operational/contingency medical response to austere medical environments. We will discuss general medical deployment preparation and outline the steps needed to first produce an accurate medical threat assessment as well as develop a threat mitigation plan. We will touch on basic principles of equipment and supplies for the operational/contingency environment. Finally, we will discuss principles of training and personnel preparation for this capability.

General Principles of Deployment Preparation

When considering operational/contingency medical responses in austere environments two broad potential scenarios set the focus for operational planning. In one category, our organization is going to perform some mission or task in an area where medical capability is underdeveloped. The AMP‘s medical capability is needed to fill the medical void, specifically in terms of caring for the aviators and other support personnel that are part of that mission. We plan to “care for our own” with maybe some assistance provided to local peoples in cases that are either emergencies or politically necessary. In another category, our medical unit is reporting to an area where the medical capability is either underdeveloped and/or it has been seriously compromised by some natural or man-made disaster. In this case, our primary mission may be to provide care to the local population as well as support other aid workers who are there to support the situation in nonmedical roles.

The tremendous variety of environments the AMP may be required to respond and operate in will frustrate any attempt to have a single operational plan that will cover all scenarios. What is needed is a process that can be used to assess the situation to be supported, define the medical threats, and develop a plan to mitigate those threats while insuring successful mission completion. It is important to remember that the delivery of medical care, per se, is rarely the primary mission goal and more typically serves a greater good. The ability to maintain focus on the broader goals will help the AMP to tailor the medical support piece such that it contributes to overall mission accomplishment and increases the likelihood of success.

The Process

The basic process of performing a medical assessment of the situation requires that four general steps be completed: gathering intelligence, identifying threats, developing threat mitigation strategies, and development of emergency plans.

A. Gathering intelligence

Obviously to plan, we must have an understanding of the situation. This understanding must include the chronic and acute medical situations in the area as well as the expected mission that you and the personnel you are supporting, will be executing. The availability and accuracy of “facts” concerning the situation are often limited at this point. Therefore, there are advantages to thinking of what you “know” about the situation as less than certain. The AMP must recognize that even the best intelligence available will still involve some uncertainty. Wisdom dictates maintaining a conservative posture and not relying excessively on any particular piece of information. It also implies a need to continually update the understanding of the situation as new data become available. Both of these considerations will benefit the AMP as she/he develops and refines plans for medical support of the mission.

There are six basic intelligence or information categories that ideally should be understood to begin the planning process. These include: overall mission goals, physical threats/security, populations involved, geographic locations, anticipated environmental interactions, and billeting and messing.

1. Overall mission goals

As stated previously, it is rare that the delivery of medical care will be the overriding goal in a disaster situation. Almost all disasters have at their root problems greater than limited medical care. It is frequently tempting for the medical personnel to focus exclusively on the delivery of medical care. However, this failure to understand the greater mission requirements and to see medical capability as simply one of the tools to achieve those overall goals, may significantly limit chances of their success. In the worst situations, the medics may actually divert limited resources away from areas where they may do the most good in a myopic effort to address the medical issues they are focused on.

In cases of natural disaster, the reestablishment of infrastructure and rebuilding of communities is the overarching goal. Medical capability is an important requirement to support rescue workers and community development teams who are more directly involved in those tasks. Care to the local population may also be a requirement, especially early on. However, provision of care to the disaster victims must be administered cautiously to avoid negatively affecting the local capability and leaving the population less well served in the long run. The primary goal of medical care provided to the local population should always be the strengthening of the indigenous medical capability with individual benefit secondary.

In cases of man-made disasters from war or terrorist activity or even in chronic situations of ineffective local administrations and a degraded social structure, the primary mission goal will be establishment of a peaceful and more self-sufficient society. Medical care in these cases may simply be one way of winning the “hearts and minds” of a population to assist in pushing a more acceptable political agenda. Political necessity may divert medical care away from the areas where it appears it would be better utilized. This can be an ethical dilemma or a difficult situation for some medical professionals. However, failure to recognize this reality may lead to unproductive use of medical resources and even undermining of the overarching goal.

In any case, it is important that the medical personnel going to a crisis environment understand the broader nature of the problem as well as the overarching goals of the nonmedical groups who respond. Dramatic “saves” by the visiting medics can serve as beacons of hope to build confidence and support or they can simply undermine the local medical providers and leave the area less well served in the long run. Decisions about how and when to apply medical capability
to these complex situations must be considered within the larger context.

2. Physical threats/security

A basic understanding of physical threats against your medical organization and/or the personnel or population you are going to support is vital to your planning. It assists in estimating the types, quantity, and severity of injuries you may expect to see. In military terms, this would be summarized as the enemy situation and would include estimates on the number of enemy, their tactics, and what weapons they are likely to use. This information is germane to civilian missions as well. The security situation, threats of terrorist action, and other violent crime that might threaten the medical and other personnel is vital to planning personnel, equipment, and evacuation requirements of the mission. In most cases, the AMP will play an important role in advising the leadership of the overall response about security limitations and the potential impact intentional trauma will have on both safety and the medical situation. In almost all response situations, input from security professionals is vital to gathering accurate intelligence as well as the development of security measures to insure unit safety.

3. Populations involved

In the case of missions where medical assistance is simply a support piece of a larger mission, there is a need to know the demographics of the personnel supported as well as the general population health status. A group of older contractors tasked to support construction of a dam will present very different medical demands than would a similarly sized group of active duty Navy Seabees doing the same job. Furthermore, if supporting an international effort, it is valuable to know how many personnel from what other countries will be there assisting. What is their baseline level of medical care and what capability are they going to bring in their support? More importantly, their existing expectations and cultural practices help to appropriately guide the medical care delivery.

Additionally, it is vital that you have a reasonable estimate of the demographics of the local population. The AMP should understand the total population size, and how the population is distributed by age, gender, and existing disease burden. In assessing the location, it is important to have an overall sense of what the health status is, (or in some cases, what it was before the event that is bringing you there). Similarly, a baseline assessment of medical infrastructure and capability is useful. Often the actual “on the ground” case is not as clear-cut as originally conceived. Even in some very underdeveloped areas, modern and high-quality medical care may be available but not in the same cross sections. For example, physician capability may be very good while nursing and para-professional care is much more limited and will require the AMP to plan to “fill these gaps.”

A basic understanding of culture and customs is valuable and prevents mistakes which, at the least, may be embarrassing but which can represent a real barrier to the provision of care delivery. Though often overlooked, it is important to understand some of the health care systems and management in the location you will be operating. Specifically, try to assess how medical care will be compensated for and what reasonable and customary compensation is. It may be prudent to charge for the care you and your organization provide if only to avoid undercutting local medical infrastructure. In the most optimal situations, the responding medical personnel will make great efforts to work within the existing care system. This may require greater cultural sensitivity and sacrifices of autonomy but ultimately can lead to the best overall outcomes. Successful efforts to strengthen the local capability will pay dividends long after your individual efforts are forgotten. Even in situations where your primary role is support of a response team and direct care of locals is not anticipated, this knowledge will be valuable.

4. Geographic locations

The next area that you must to understand is the location(s) to be deployed. This may represent what most of us think of as “the environment.” Information is needed about temperatures, humidity, precipitation, altitude, and prevailing winds in addition to understanding the insect vectors and other animal threats that might affect personnel. We need to have a sense for the nature of the geography—is it flat and easy to move across or rugged to the point that land travel is difficult? Are the roads passable and how quickly? It is also important to recognize that, in many contingency situations, success at one location may result in movement to one or more subsequent locations. The AMP should plan for not only the first site but also for potential follow-on locations.

5. Anticipated environmental interaction

In addition to the medical capabilities and shortfalls of a location, one must understand the environment in terms of the expected interface it may have with those deploying to the site with you. A contaminated sewer system presents a very different threat to a teacher tasked to teach agriculture skills in a classroom than it does to a communications worker who must enter confined spaces partially filled with runoff to get to the telephone lines. Personnel working at night may be exposed to different set of disease and injury threats than those working in the day. Again, a basic understanding of the overarching mission as well as the roles that various responders outside of the medical support piece will play is vital to planning and preventing diseases and injuries that are likely to present.

6. Billeting and messing

Where support personnel live and eat is central to planning and will make a huge difference in the quantity and types of diseases you are likely to encounter during your mission. The facilities in which personnel sleep and rest will similarly alter
the effects of ambient temperature and humidity as well as profoundly affect the threat of vector borne disease. The source of food and how it is procured and prepared will similarly have tremendous impact on the threat of food and waterborne disease, which is often the greatest medical threat to the visiting personnel. This is another area in which the aerospace medicine professional must recognize his/her role as advisor to the leadership concerning what types of facilities are necessary and how questionable facilities can be improved to reduce the risk of disease.

B. Identifying threats and developing mitigation strategies

Once the AMP has gathered and assessed the best possible intelligence about the mission, she/he can move on to the identification of specific disease and injury threats. The nature and magnitude of these threats are highly dependent on the intelligence that will need to be gathered. In fact, the medical threat assessment is really just a more specific list of threats based on that intelligence. Therefore, additions or changes to the intelligence will likely affect the threat assessment as well.

As stated previously, each situation is different and there is no single threat assessment, which can be developed that can meet the varied demands. Rather, what is required is an iterative process that assists the AMP in considering all the potential threats and deciding which are pertinent to the situation at hand. The specific format is not important as long as it includes all of the potential threats that an environment may pose. What follows is simply one format that has been developed to address the various threat categories.

1. Intentional injury

This category includes various violent attacks that may occur against responders or locals you may be tasked to care for. In war scenarios, this may include overt attack by enemy forces. Less openly hostile situations still often include the threats of terrorist actions or simply violent crime. In all cases, the AMP may be faced with a variety of severe injuries including penetrating and blunt trauma, serious burns, and blast injuries. These injuries put a significant strain on the limited medical resources that have been brought to the situation. Furthermore, depending on the mission and the tolerance for such events, they may significantly compromise the willingness of sponsoring nations or nongovernmental groups to continue in support of the mission.

Prevention of such injuries is the most important effort the AMP can take in addressing this threat. However, preventive strategies must still support accomplishment of the mission. For example, the most effective preventive measure may be to not engage in the mission at hand—hardly appropriate in most situations. Indeed the acceptable level of risk is more a political and strategic decision than a medical one. However, it will fall to the AMP to act in his/her consultant role to discuss with leadership the effects that the potential trauma will have as well as the need to have adequate security and force protection measures in place. Individual actions should be considered and try to provide input as to how the threat of intentional injury measures against the potential value of the action. Insuring that personnel have appropriate protective equipment for the situation such as Kevlar helmets, bulletproof vests, and ballistic eye protection can can markedly improve survival in cases of intentional trauma. Additionally, efforts to insure that nonmedical personnel are well trained in trauma first aid may allow for injured personnel to get the immediate care they need to survive until they can enter the medical system. Depending on the nature of the threat, this first aid may require airway and intravenous (IV) capability.

2. Unintentional injury

Motor vehicle accidents (MVAs) continue to be a common cause of death and disability in working age individuals as well as the number one cause of death in tourists. Austere environments often present a very different and in many ways more hazardous driving environment than that which the responder may be used to. The threat of MVAs to personnel should not be underestimated.

Work-related injuries can also be a significant threat to responders. Especially in more dramatic scenarios, those wanting to help may be motivated to cut corners to accomplish tasks quickly in an effort to help. These motivations can backfire and result in excess injuries to responders and a loss of care capability. As response situations become more chronic, sports injuries and other recreational injuries can become significant sources of trauma.

Efforts to reduce unintentional injuries will consist primarily of policy decisions, which must be made and enforced by the mission leadership. The role of the AMP is to advise the leadership as to what limitations may be the most appropriate. There are several policies that are likely to assist in the prevention of unintentional injuries. The most important are informed travel guidance and limitations. The first step is to insure that personnel never travel alone. After that, insuring that personnel limit travel to appropriate vehicles will reduce the chances of MVAs and other threats. Travel by motorcycles and “hooptees” increases risk unacceptably and is rarely necessary. Travel in taxis must be done with care to insure that the vehicle is a taxi registered to a legitimate company. Careless use of taxis can result in robbery or other dangerous crime situations. In some areas, the only safe way to travel is in secure vehicles contracted from security agencies. Again, these limitations are ones that will be decided and enforced by the nonmedical leadership.

3. Disease threats

In most situations, diseases are the greatest threat to both the responder and local populations. For the purposes of developing the threat assessment, they can be grouped into several categories.

a. Food and waterborne diseases

Bacterial, viral, and parasitic diarrheal diseases represent a major
threat to responders. This threat can be greatly exacerbated in times of humanitarian crisis where food and water sources are frequently compromised. More significant conditions such as hepatitis A and E as well as typhoid fever are also tremendous threats in this environment. Rare will be the situation in which food and waterborne diseases are not a major threat to the responding population and the success of the mission.

On the surface, avoidance of food and waterborne disease would seem simple. In the “en vivo-real world” environment it can be much more difficult. People like food and will aggressively seek “opportunities” to infect themselves with these community-acquired diseases. Trying to limit the food that personnel eat to approved and acceptable sources seems to be the first logical step. However, history has shown that unless your situation is such that there are no sources of food outside those you can control, personnel will get around any limitations you attempt to impose. A less paternalistic approach that is often more successful is to educate them on what can be safely consumed and what cannot. Baked, boiled, bottled and peeled (BBBP) is an easy to remember tool that reminds personnel of the foods that are less likely to result in disease. Items taken hot off the grill or hot out of the oven are relatively safe as are foods that are naturally peeled to eat. Baked breads remain relatively safe while fresh. Commercially bottled drinks are generally safe though water, which can be easily bottled by locals using unsafe sources, is suspect. Soda and beer are the safest as the basic bottling procedures exclude survival of bacterial or viral diseases. Ironically, the greatest threat from food and drink comes from sources that may be considered “healthy” at home. Salads and other leafy vegetables as well as fresh juices may be healthy choices at home but are extremely high risk in much of the developing world. It is sometimes ironic that medical personnel who may be focused on “healthy lifestyles” have a difficult time initially accepting this situation. The good thing is that it is relatively easy to educate personnel about how to eat in the developing world and avoid disease while still allowing them to enjoy what the local economy has to offer.

Recognizing that almost no food or water strategy can completely prevent risk, prevention and treatment measures need to be insured. Hepatitis A and typhoid vaccines are near constant requirements.

Antibiotics, while not necessarily a common part of diarrhea treatment in the developed world, have a more frequent role in the developing world. Additionally, depending on your situation, the ability to have IV therapy available for patients who become significantly dehydrated may be very limited. Intravenous solutions are relatively heavy and can be prohibitive in amounts needed to treat diarrheal outbreaks. Oral rehydration solution is a much more rational approach in a weight-limited environment. Not only can the ingredients be found in almost any location you might be operating in, if necessary, it can be included in the supply kit at little cost.

b. Vector-borne diseases

Conditions such as malaria, dengue, yellow fever, leismania, bartonella, trypanosomiasis, plague, as well as a host of encephalitic and hemorrhagic fevers can all represent significant threat to populations in many world environments. The global distribution of these conditions and the threat they present are typically well understood and available through various intelligence sources. It is worth noting that humanitarian disasters may break down previously successful control measures and result in the condition emerging anew or reemerging where it was previously controlled. These are conditions that can rapidly compromise a response team and quickly take them from an asset to a liability in a disaster scenario.

Most of the preventive measures that can be deployed against vector-borne threats will be the same irrespective of the geographic location or the specific threats. The most important preventive measures are barriers that prevent the insect from biting and passing the disease to the individual. In locations where the billeting situation does not provide adequate mosquito prevention, pyrmethrin-treated bed nets are the single most effective intervention you can provide. The more modern versions are compact, packable, and extremely easy to use.

In addition to bed nets, leadership-directed wear of appropriate, pyrmethrin-treated clothing by personnel could greatly reduce the risk of mosquito and other biting insect vector disease. This is especially important during the dawn/dusk time period when personnel may be off duty and relaxing in typically less insect protective clothing. The final prevention barrier is the application of diethylm-toluamide (DEET) insect repellent to the skin at appropriate intervals. The best DEET preparations are those which are lower concentrations (˜20%-50%) but which are microencapsulated to provide a longer lasting and more consistent level at the skin.

Beyond barrier prevention, specific disease interventions should be undertaken where appropriate. Immunizations against specific diseases such as yellow fever and Japanese encephalitis are important in the regions they are found. Additionally, prophylaxis against malaria is an effective and critically
important preventive strategy in the large areas of the world that are affected by this condition.

Although there are a variety of medications available, determination of which one is best for the individuals who are going to deploy can be a daunting task. Weekly dosing of Chloroquine, Mefloquine or Malarone, or daily application of Doxycycline or Primaquine are among the more commonly used prophylactic malaria medications. The website at the Centers for Disease Control and Prevention (CDC) provides up-to-date risk and resistance guidance for common prophylactic measures and medications. Each has its advantages and disadvantages, some of which can be significant side effects in certain patients. Chloroquine is well tolerated by most patients but resistant organisms have greatly limited its geographic usefulness. Mefloquine is also reasonably well tolerated although neurologic side effects and political fallout from personnel who have blamed criminal behavior on the drug may be significant concerns. Malarone, which is a combination of atovaquone and proguanil hydrochloride, is approved only for the prevention and treatment of falciparum malaria but appears to work well for all malaria species. It is well tolerated and effective but relatively expensive. Doxycycline is commonly used but has several negatives including a daily use requirement, gastrointestinal (GI) upset, and sun sensitivity. Finally, the use of primaquine daily throughout the exposure period may be effective but cannot be used in G6PD deficient patients and represents off-label use.

In addition to prophylactic medications, the AMP must insure the medications for treatment of suspected and confirmed acute malaria infection is available. This is especially important for falciparum malaria that has the potential to be rapidly fatal. Malaria infection is classified as severe if infection is associated with impaired consciousness, coma, seizures, shock, renal failure, hemoglobinuria, pulmonary edema, acute respiratory distress syndrome (ARDS), diffuse intravascular coagulation, acidosis, severe normocytic anemia, or a parasitemia of more than 5% of erythrocytes. These severe cases typically require inpatient treatment in an intensive care setting with a combination of IV and oral medications including Quinidine gluconate. Quinidine can be somewhat difficult to find and must be arranged for before the need arises. Cases without those complications listed are referred to as uncomplicated and can be treated with a variety of oral medications in an outpatient setting.

Over time, specific medications and recommendations may change. The types of malaria present in specific locations and the resistance of those organisms to various medications may drift. The AMP will need to insure that she/he is up to date with current recommendations for the region being supported to provide prevention and treatment for those personnel under his/her responsibility. Organizations like the CDC in the United States can be relied on for up-to-date recommendations either on their website or in hardcopy form. (http://www.cdc.gov/malaria/diagnosis_treatment/tx_clinicians.htm) Those supporting military operations may have the luxury of mandating malaria prophylaxis for “the force.” It is important for the military AMP to remember that enforced prophylaxis must be done in keeping with the U.S. Food and Drug Administration (FDA)-approved indications of the medications. Civilian organizations may have more latitude to use medications “off-label” but they are required to apply these medications one-on-one with individual risk benefit calculations done for each patient. In the end, the AMP must have a detailed understanding of malaria medications before planning operations in a malarious area or risk mission-compromising infections that malaria can and has presented to operations throughout our history.

c. Person to person

Conditions that are spread person to person have the capacity affect deploying personnel as well as to present as large outbreaks in humanitarian disasters where the population immune response may be compromised and where large groups of people are brought in close contact. Threats include pneumonias, many of the vaccine preventable diseases such as measles, as well as the sexually transmitted diseases and mycobacterial infections of tuberculosis (TB) or leprosy. The medical condition of the native population as well as the customs and interactions they will have with the response personnel will assist in estimating how great the threat will be.

Vaccine-preventable diseases are thankfully straightforward to address using the specific vaccines. Sexually transmitted disease threats are highly dependent on the behavior of the deploying personnel and can largely be prevented by appropriate education before and during deployment. The enormous risk of human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) has made educating personnel and gaining their cooperation easier although efforts to curtail sexual activity completely will rarely succeed. It is still vital that the AMP be available to provide safe sex alternatives and education as even the most well-intentioned traveler can be overwhelmed by the availability of unsafe sex opportunities in much of the developing world.

Additionally many operations place personnel at risk for occupational exposure to blood and body
fluids. The ability to test sources may be limited and in some cases source testing may not be an option. The AMP does not need to be an expert in HIV treatment but she/he should understand the basics of post-exposure prophylaxis including expected side effects. Additionally, the AMP must insure that post-exposure prophylactic medication on hand in the case of possible exposure until the source can be tested or until contact information can be evaluated and further recommendations provided.

Among the most difficult conditions to protect personnel from are the mycobacterial infections. Leprosy transmission is so slight that in practicality it represents a small threat. TB is a real risk and skin testing to assess for latent TB infection should be done before entering and between 3 and 6 months after leaving a high-risk area. Complete recommendations on testing and treatment of latent and active TB are outside the scope of this chapter but can be accessed from one of several frequently updated sources. (http://www.cdc.gov/nchstp/tb/pubs/mmwrhtml/Maj_guide/List_date.htm)

d. Animal or water exposure

Animals and swimming or wading present the risk of unpleasant situations from land-based and waterborne risks. Poisonous reptiles and insects can inflict venomous bites. Larger predator animals in some areas can inflict life-threatening injuries. Thankfully, contact with these is relatively rare. However, exposure to domestic or feral pets is much more common and often even sought after by the responding personnel. These animals can present the risk of bites and scratches and, on a more concerning level, rabies. Swimming or wading carries with it the risk of drowning, hypothermia, and other cold injuries such as immersion foot. Wading or swimming in fresh water bodies in large parts of the world also presents the risk of diseases such as schistosomiasis and leptospirosis.

Appropriate education of personnel as well as strict application of relatively straightforward leadership-enforced directives such as “no pets or mascots” and “no swimming or wading in natural fresh water bodies” can reduce the risk significantly. If the mission requires care of feral animals, those who may be exposed should be immunized against rabies and provided appropriate equipment and personal protective equipment (PPE) to reduce the risks of bites. If opportunities for recreational swimming are desired, it falls to the AMP to assess the risk and insure that leadership has accurate information about the situation. Only then can they make rational decisions about the risks and benefit of such opportunities to insure that personnel are protected.

e. Environmental threats

Climatic and geographic conditions such as heat, cold, altitude, ultraviolet (UV) exposure, and even pollution present threats to the deploying personnel. Although these conditions seem straightforward, the list of operations that have been completely compromised by heat and cold alone is long and distinguished and spans time from the distant past to near present.

Severe environmental conditions will reduce a force’s capability, even if they successfully mitigate against them. They will, at best, lose time and effort as they deal with environmental challenges. Extreme cold requires clothing that limits dexterity and requires time to don and doff. Extreme altitude will reduce the amount of work even those who acclimate can accomplish while requiring that some personnel be returned due to failure to acclimate. The AMP must recognize these threats and act strongly as the advisor to his commander to inform him as to how the threats will limit his force’s capability and require additional personnel to accomplish the same tasks. For example, an organization that requires 400 personnel to perform their typical mission may require an additional 20% to do the same task at a base camp at 12,000 ft elevation.

f. Pre-existing disease

The final issue in consideration of disease threat is the preexisting condition of the individuals to be supported. Injury and disease threats are always experienced in the context of the individual exposed to the condition. The medical condition of personnel is a major factor in determining how they will compensate (or fail to compensate) for many of these threats. This text does not allow for a discussion of the many medical conditions that might affect injury and disease threats in unique austere environments. Nevertheless, the AMP must be aware of the population she/he anticipates supporting and consider the medical condition and fitness that they bring to the situation in trying to do his/her contingency planning. Some conditions may lend themselves to mitigation attempts. Others may simply not be consistent with the planned operation and the AMP may have to take the role of advising his/her commander concerning appropriate physical standards for the personnel selected to support the mission.

4. Emergency plans

Despite the best planning and efforts at prevention, bad things will sometimes happen. Personnel may be seriously injured or may become seriously ill far from access to established medical care. Without access to traditional fixed medical capability or expert consultation, the AMP must insure the basic capability to provide initial stabilization including airway control, advanced cardiac life support (ACLS) capability, bleeding control, as well as blood and fluid
replacement. Depending on the geographic area of responsibility, this initial stabilization capability may need to be available in kits that can be taken easily to the site of injury or to meet the injured as they are brought toward your facility.

For severe trauma, surgical intervention will be required. Discussions and opinions abound about how near surgical capability should be located to areas of potential injury in the deployed environment. All too often, there will not be sufficient surgical assets to position them near all the potentially dangerous operations. The AMP planning the mission must have some appropriate standard for how near surgical capability needs to be. Data to support this kind of decision comes from studies concerning small arms injuries and survival in wars from the U.S. civil war to the recent conflicts in Afghanistan and Iraq. These studies support the added survival value of surgical intervention within 6 hours of point of injury but not necessarily sooner.

To meet the goal of having surgical intervention within 6 hours of point of injury may necessitate bringing organic surgical capability with you as part of your support even when it is not part and parcel of the overall mission. However, in many cases the additional personnel and equipment needed to establish surgical capability in an austere medical environment represents a significant additional logistics burden. In these cases, surgical capability may be found using either host nation or surrounding nation capability. Assessment of these facilities and actual capability may be estimated by written or telephone intelligence before deployment into the area. However, confirmation of the actual capability should have a high priority and be completed as soon as possible after arriving. This includes developing an acceptable understanding with the local hospital and surgeons for access and reimbursement. As this is done, it may be easy to assess other medical capabilities available at the location and further enhance your capability. This will allow the AMP to reduce the chance for unanticipated shortfalls in surgical or other specialty capability that could affect the ability to insure quality care for your aviators and support personnel.

C. Communicating with leadership

Once the AMP has completed the threat assessment and developed mitigation strategies to prevent levels of illness and injury that may compromise the mission, he must communicate these to the people who can implement them. It is rare that the AMP will have authority within the organization that is responding to the contingency to designate or enforce policy. It is, therefore, vital that she/he garner the support of leadership to implement his/her recommendations. AMPs, at this point, maybe tempted to outline their entire assessment and strategy just as they have worked it out. Often this will result in a too-lengthy report for the leadership attending to many other requirements. A better way to organize the leadership brief may be by using a chronology.

The first issues addressed are those that need to be accomplished before the deployment to the contingency location. These issues involve selection and standards for personnel to support the mission, immunizations and prophylactic medications that will be required, and PPE and other gear that may be required to mitigate disease or injury threats. It may also include a requirement for medical to be represented in advanced team reconnaissance missions that may precede the main group deployment. These are presented in a concise list with a clear message to the leadership that these are important issues and that the AMP, as the consultant to the leadership, is asking the leadership to require and enforce these as part of the overall mission policy.

The second issues addressed are those that need to be in place during the deployment. These issues involve travel limitations, billeting, clothing and uniforms, application of insect repellents, use of bed nets, compliance with prophylactic medications, interactions with the local population, food and water sources, and early reporting of illness and injury to the medical personnel. Again, the AMP must emphasize to the leadership that these are recommendations designed to mitigate against disease and injury threats, which will require leadership enforcement to succeed.

The third set of issues are those that will be required upon completion of the mission. Issues such as testing for latent TB infection, reporting of health status upon completion, and collection of medical records kept during the deployment may all fall into this category.

The final issue that should be part of the AMPs briefing to leadership includes the emergency response and evacuation plan. When activated, these plans will often require resources such as vehicles and aircraft, which are outside the direct control of the AMP. Therefore, it is vital that leadership knows what the plans are and what the requested resources might be in the various scenarios. Again, it is important at all stages that the AMP emphasizes that his/her recommendations will only be effective if they are endorsed and enforced by the leadership.

AIR MEDICAL TRANSPORT

As the AMP looks to emergency plans that require increasing acuity or higher echelons of care to which patients will be transferred, the capability to move patients by air quickly becomes an important issue. In fact, the need to care for patients in-flight is a unique and challenging environment in its own right. In this section, we will focus specifically on the broad range of air medical transport capabilities.

Introduction and Definitions

Air medical transport is the use of aircraft to rescue, move, and care for patients, and to support medical operations. Air medical missions are most often from the scene of injury or illness to a hospital, often called scene missions, or between hospitals, often called interhospital missions. The unique aircraft environment and its effects on the patients and crew must be considered during air medical operations. They cannot be the primary focus during missions or in the field of air medical transport research. Air medical transport research, instead, is focused on the care of patients in the aviation environment, with proper consideration for aeromedical issues along with other factors. Therefore, aerospace medicine and air medical transport overlap in some ways but can be considered two distinct fields.

The air ambulance is only part of air medical care. The vehicle and medical crew represent a sophisticated system of care that alters local medical capabilities. For example, the addition of an air ambulance to a regional health care system may allow development of a specialty care capability, such as a neonatal intensive care unit or a liver transplant service. It may also strengthen the ability of regional emergencymedical service (EMS) systems to provide care for trauma, cardiac, or pediatric patients by providing high level out-of-hospital care over a broader geographic region than could previously be covered by ground vehicles. Physician medical direction is essential in the planning and operation of an air medical program, and is best provided by physicians trained and experienced in critical care transport medicine. The Air Medical Physician Association is one organization that provides a forum for training, support, and professional development of physicians involved in air medical transport (1). The Aerospace Medical Association provides a forum for those interested in advancing scientific knowledge regarding the health, safety, and performance of those involved in aerospace medicine (2).

History of Air Medical Transport

Shortly after aircraft technology progressed to the point that passengers could be flown, they were recognized as a means to move persons in distress. There is some debate about the first intentional patient transport by air, including the date and whether the aircraft was a balloon or a fixed-wing airplane (3). Regardless of the aircraft used, the history of air medicine is linked to military conflict. The helicopter was first widely and successfully used during the wars in Korea and Vietnam. It offered advantages of access in hostile terrain and rapid transport speed compared with ground alternatives (4). The helicopter developed significantly from an aviation perspective during the time between those two conflicts. The aircraft typically used during the Korean conflict for field rescue were light helicopters that carried the patient on externally mounted stretchers. Medical care was limited to measures before flight, because there was no access to the patient until landing.

By the Vietnam War, larger helicopters, such as the Huey, with interior cabins of sufficient size to fit stretchers and medical providers, were available, and patients were usually transported inside the aircraft. This allowed medical attention during transport. Dr. Spurgeon Neel, an Army flight surgeon, played an important role in the design and development of the Huey, assuring that air evacuation was in mind during the process. The helicopter rapidly became a favored aircraft for short-range patient rescue and transport in U.S. military operations, with 110 air ambulances in Vietnam performing more than 7,000 evacuations monthly by 1968, and approximately 900,000 total missions during the 11 years of operation in Vietnam (5,6). Similar military helicopter use continues, with helicopters figuring prominently in field medical care in subsequent conflicts and in current U.S. (and other) military deployments. During recent conflicts in Afghanistan and Iraq, helicopters were used to deliver patients to and from field hospitals such as those staffed by forward surgical teams (FSTs) and as a link between this immediate field care and secondary care on hospital ships or in support hospitals. Fixed-wing aircraft are used for longer distance patient transport and for logistic support. These missions include evacuation of injured soldiers to military medical centers in the United States and bases supporting troops in action.

Significant civilian application of helicopter medical care within the continental United States began as personnel experienced with military air medical helicopter operations returned from Vietnam during the 1960s and 1970s. They proposed that similar technology would be beneficial in the civilian environment, particularly for trauma victims (7). Other countries also developed air ambulance services, some focusing on emergent patient transport, some on delivery of medical resources to remote areas, and others on rescue.

Justification for Air Medical Transport

Common sense suggests that patients with survivable illness or injury can benefit from appropriate care delivered before arrival to a hospital setting if it can be done without excessive risk. In a hostile military situation, where medical capability may need to be somewhat distant from areas of likely injury and where other means of transport are not readily available (because of terrain or enemy threat), there are clear advantages to helicopter medical transport. Justification for use in the civilian environment is often less clear.

When considering this justification, there should be clear advantages to use of the aircraft system. This could either be due to the aircraft capabilities, the medical crew carried, or both. For example, many medical conditions worsen rapidly without prompt advanced care. Time saved, therefore, is a potential advantage of aircraft use, whether the aircraft brings the patient to a hospital capable of this care or brings skilled advanced care staff to the patient. In most systems, the air medical crew is highly skilled and trained, with extensive experience in critical care transport. Their expertise may not be available by ground because of time, distance, or area covered. Although their presence cannot replace the hospital, their advanced skills, experience, and equipment may provide a patient care advantage over care available
from ground EMS resources. In fact, it is a requirement that the skill level of the air medical crew be at least as high as that of the responding EMS as it would not be appropriate to hand off care to a lesser capability. In many cases, the advantages of speed and access afforded by the aircraft are augmented by the medical crew capabilities; the patient benefits from both.

Unfortunately, these theoretic advantages of civilian air medical transport are often difficult to demonstrate objectively. Confounding factors include educational efforts for referral facilities, coordination with tertiary care hospitals for consultation before and during transport, increasing regionalization and specialization of health care, and continuing parallel advances in ground EMS and emergency medicine. All these factors are difficult to analytically separate from the effects of the air medical aircraft or crew alone. Early scientific analysis of helicopter medical care focused on trauma, with some consideration for cardiac, pediatric, and obstetric patients. Additional efforts included appropriateness of use, estimation of need, and clinical techniques during flight. Although a wealth of helicopter medical literature exists, rigorous appraisal of patient outcome benefit has been limited by sample size, the confounding variables noted earlier, and lack of concurrent control groups (8). There is less extensive literature evaluating fixed-wing air medical care and even less on long-distance (“repatriation”) care during commercial airline flight.

Therefore, many air medical programs are established and others continue to operate based on anecdotal evidence of benefit. It should be stressed, however, that ground EMS systems, and many other aspects of medical care have no greater objective justification in terms of improved patient outcome or public health benefit than the evidence that exists to justify air medical care. The continued existence of civilian air medical rotary wing programs and the recent emergence of privately run for-profit programs providing similar service argue that there is at least a perceived benefit.

System Types

Many factors influence the design of air medical systems. Considerations begin with general safety and the specific system mission. Search-and-rescue (SAR) operations, for example, focus on finding and removing the victim from an endangering environment. The aircraft choice, equipment installed, crew selection and training for SAR missions will require a significantly different approach than a system designed for optimal interhospital patient transport. Efforts to develop platforms capable of multiple missions can add capability but may result in compromise. In many cases, platforms capable of interhospital and transfer and accident scene response can be developed logically, whereas SAR, mountain rescue, high-altitude operations, or rescue at sea missions require specific solutions. This chapter does not cover SAR operations in detail, and the reader is referred to specific texts on that subject (see Recommended Readings).

System configurations may be grouped based on the mission, type of aircraft used, medical team and resources, and availability. There are hundreds of part-time (the aircraft must be reconfigured from other uses such as executive transport) fixed-wing air medical programs that perform elective transport of stable patients as one of their primary missions using on-call medical crew. There are also many (˜250 in the United States) full-time dedicated helicopter air medical programs. Many are small units utilizing one or two helicopters. Most are based at or supported by hospitals and staffed with medical professionals who work at those facilities. However, many are located strategically to provide rapid access to a geographic area at bases such as airports, fire stations, and so on. Physicians, nurses, paramedics, and respiratory therapists are the most common members of the air medical crew, with physician assistants, nurse practitioners, and other providers found in some systems.

Some systems offer both fixed-wing and helicopter service, and an increasing number coordinate with or directly provide ground ambulance transfer as well. Few civilian air medical systems in the United States focus on SAR operations, leaving that mission to the Coast Guard and other military/public service agencies. However, many U.S. programs perform limited search operations, and some train in regionally specific rescue, such as hover operations over water, snow, or wilderness terrain. In other countries, the rescue mission is often a component of civilian air medical systems, with winch lift and other rescue functions. Interfacility helicopter transport is increasingly common in non-U.S. programs.

A recent review showed the typical U.S. helicopter program performed approximately 800 patient missions annually over the last 5 years. Approximately one third of these missions transported the patient from the scene of accident or illness and two thirds moved between hospitals, with an average patient transport distance of 88 km (55 mi). Approximately one third of missions occurred at night. There has been a gradual trend toward increases in annual patients per program, transport distance, and overall flight hours in most regions of the United States during the last 5 years (9).

Standards

In the United States, civilian rotor-wing air medical programs predominantly transport patients from the scene of accident or illness to a hospital, or between hospitals. A small number of programs routinely participate in limited SAR operations, and an even smaller number see SAR as their primary mission. Fixed-wing programs transport between airports, with the patient being transported between hospitals in almost all cases. Exceptions include programs such as the Australian and African Flying Doctor Services, which operate mainly in remote rural or wilderness areas.

The Commission on Accreditation of Medical Transport Systems (CAMTS) is the predominant accrediting body for civilian rotor and fixed-wing transport systems in the United States (10). CAMTS has standards for basic life support (BLS), advanced life support (ALS), and specialty levels of care. These standards address safety, staff qualifications, communications, equipment, patient care, documentation,
follow-up, quality assurance, and other aspects of air medical operations. The CAMTS Board of Directors accredits air medical transport programs after a satisfactory site inspection and review of extensive documentation to document compliance with applicable standards. CAMTS accreditation is recognized by many states and medical insurers, but is currently voluntary in most states. Because many air medical programs operate ground critical care transport services as well, CAMTS is also involved in accrediting this aspect of critical care transport, and has developed ground BLS standards for programs that provide this aspect of care along with critical care air and ground transport. Unlike military medical crew or crews on commercial airlines, the medical personnel on air medical aircraft are considered passengers and are not regulated as crewmembers by Federal Aviation Administration (FAA) standards or regulations.

In addition to CAMTS standards, air medical crews must also comply with state, regional, and/or local medical laws, regulations, and standards. In addition, hospitals and other health care facilities have internal credentialing standards, as do some reimbursement systems. These requirements vary widely, with few widespread standards. Although national certifications exist, they do not confer practice permission in specific jurisdictions. This situation causes potential conflict, with air medical providers potentially not licensed in the state, credentialed in the region, or accepted as a member of the hospital staff where they are caring for a patient. In other situations, air medical crew are trained in and perform procedures that are not within the allowed skill set for providers with similar credentials operating in ground EMS systems in the same region. Various solutions, from national medical licensing and practice credentialing to invoking the theory of mutual aid to imply “temporary credentials” for providers without local credentials have been applied to resolve this practice conflict.

Aircraft and Aviation Equipment

Most helicopters involved in air medical operations are dedicated to the purpose. Specific aircraft model, interior design, and equipment choice follow the intent to provide medical care. The most commonly used aircraft models are small and midsized twin-engine and midsized single-engine aircraft (11).

These helicopters are generally turbine powered, with the proportion of twin-engine aircraft relative to single-engine aircraft steadily increasing. Several manufacturers have introduced models in the last few years that claim design to specifically accommodate air medical needs. Cruising speeds of 160 to 257 km/hr (100-160 mi/hr) with ranges of 520 to 885 km (325-550 mi), a useful payload of 680 to 1,360 kg (1,500-3,000 lb), and service ceilings of 3,962 to 6,090 m (13,000-20,000 ft) are characteristic of these light midsized helicopters.

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