Air University Review, March-April 1968

Aeromedical Evacuation in Southeast Asia

Lieutenant General Kenneth E. Pletcher, USAF (MC)

Thousand of U.S. fighting men are alive today because speed, new techniques, and trained personnel of aeromedical evacuation teams are giving the wounded in Vietnam better than twice the chance of survival than ever before.

The movement of patients from the battlefield and initial treatment points to specialized medical facilities has long been a problem and major concern of field commanders. The sooner a patient receives professional medical attention, the more likely he will recover and the sooner he will return to duty. This is especially important in combat, where troop strength must be maintained at the highest possible level. The key to the problem is speed—getting the patient to an adequate medical facility as quickly as possible.

New lifesaving techniques and equipment being used in Vietnam today include frozen whole blood, artificial kidneys, blood volume machines, and an ultrasound device that can locate shell fragments deep within the body by sonar. But the biggest step forward is the rapid airlift of wounded from the battlefield to a facility where they can be given the advantages of these new developments.

Although Air Force C-141 Starlifters can airlift a patient from Vietnam to a hospital in the United States in less than 24 hours, the most critical period occurs within the first few hours after he is wounded. In Vietnam, because of the terrain, dense foliage and other overland hazards, moving wounded by ground transportation is virtually impossible. Evacuation by air is the only solution.

Why the emphasis on airlift of casualties to the United States?

Field hospitals in Vietnam need bed space. No more than 60 percent of beds should be full at any one time. When new casualties come in, “old” patients must go. And in Vietnam, the only quick way out is “up.”

Jet-evac of casualties makes sense from a logistic point of view. There is no wasted airlift with jet-evac. C-141 Starlifters that speed troops and cargo to the war zone are refitted—on the spot—with aeromedical equipment and supplies for a return trip with a full load of patients.

Jeep and ambulance trips from the battlefield to treatment points are almost a thing of the past. Airlift cuts shock and infection among wounded by at least two-thirds, more than doubling their odds for survival. No one is more than 25 minutes away, by air, from lifesaving surgery. Further, the skills of medical and surgical specialists now can be concentrated in the United States at institutions where the best of modem equipment already is installed and working.

The benefit of quick evacuation to the morale of the fighting man—and his family—is an obvious but important answer to the why of aeromedical airlift. Only one percent of all personnel injured by hostile action in Vietnam die after reaching a medical facility. In Korea, where fewer than 15 percent of the wounded were moved by helicopter, the rate was 2.5 percent; and in World War II, with no helicopters, the rate was 4.5 percent.

the how of aeromedical airlift

Aeromedical evacuation can be separated into four distinct systems: (1) forward aeromedical evacuation, (2) tactical and intratheater aeromedical evacuation, (3) strategic and intertheater aeromedical evacuation, and (4) domestic flights.

Although the first three systems operate independently of each other, each includes personnel of all services, and a common purpose combines their efforts, providing an integrated, smooth-running operation. The key word in management of the Air Force aeromedical lifeline is “flexibility.” Scheduled flights move patients within Vietnam and to hospitals outside the combat area. But where those flights stop first—or last—or whether they stop at all—is determined by the seriousness of illness or injury of patients and by the need for bed space in field hospitals.

Evacuation from the battlefield is generally by Army or Marine helicopters that operate during the heat of battle, many times under intense enemy fire. It is estimated that more than 90 percent of all U.S. wounded in Vietnam are evacuated from the combat area by helicopter. In some cases, where the terrain and conditions permit, the wounded are evacuated directly from the combat area by Air Force C-7 A, C-123, or C-130. These missions are extremely dangerous and require a very high degree of professionalism on the part of the crew members. Casualties are airlifted to treatment points within the combat area, and here we enter the second stage of the system—tactical and intratheater aeromedical evacuation. Patients are airlifted from airfields within the combat zone to facilities outside the combat area, and between points within the theater. This is the phase of the evacuation with which PACAF is concerned.

Intratheater flights move patients within a specified overseas area or combat zone. In Southeast Asia, for example, air movement of patients within the battle area and to U.S. military hospitals in Japan, Okinawa, or the Philippines is the job of intratheater airlift. Control of intratheater flights in Southeast Asia rests with a command post at Tachikawa Air Base, Japan. Serving as primary aircraft for intratheater air evacuation, C-118s are single-purpose aircraft, used only for aeromedical flights.

The third portion of the system, strategic and intertheater aeromedical evacuation, is the responsibility of the Military Airlift Command (MAC), which provides flights from overseas areas to the United States. Regularly scheduled flights leave from Tan Son Nhut, Cam Ranh Bay, and Da Nang Air Bases in Vietnam for aerial ports at Andrews AFB, Maryland, and Travis AFB, California. The aircraft stop en route at Yokota AB, Japan, a patient transfer point. Patients destined for hospitals east of the Mississippi fly to Andrews; those for hospitals west of the Mississippi fly to Travis.

The domestic phase of the system, which moves patients from ConUS points of arrival to their final destinations, is also operated by MAC. Aeromedical evacuation units do not determine the patient’s destination hospital; instead, this is the responsibility of the originating medical facility in conjunction with several regulating agencies. The first agency is the Far East Joint Medical Regulating Office (FEJMRO), located at Camp Zama, Japan. If a patient is to be hospitalized in the Far East or Southeast Asia, FEJMRO determines where he goes. Prior to a patient’s leaving an overseas area, the Armed Services Medical Regulating Office (ASMRO) in Washington, D.C., determines where he will be hospitalized in the United States. When he arrives at either Andrews or Travis, the patient is moved by trunk and feeder lines to his destination hospital. Trunk flights move on schedule between seven main transfer points throughout the U.S.: Travis, Buckley, Kelly, Maxwell, McGuire, Andrews, and Scott AFB. At the transfer point nearest his destination hospital, the patient boards a feeder flight for the final leg of his journey.

In the States the 375th Aeromedical Airlift Wing Command Post at Scott monitors all trunk and feeder flights, with an aircraft taking off or landing every 17 minutes. A telephone “hot line” links each of the seven transfer points to the command post at Scott. Hot lines permit conference calls between any or all units. Status boards at the command post show how many patients need to be moved, what aircraft are available to move them, and the progress of each enroute patient.

determining patient destinations

Several policies and factors determine where a patient is to be hospitalized. Generally speaking, a patient who is to be hospitalized for 60 days or more will be returned to the United States. For fewer than 60 days, he will go to a hospital within the Pacific Command (PACOM). But this is not a firm policy; it is flexible enough to allow a patient to remain at a PACOM hospital up to 120 days if hospital space is available. The 60-day policy applies to all hospitals within PACOM except Vietnam, where the normal limit is 30 days.

A patient normally will not move unless bed space is available for him elsewhere. In Vietnam bed space in all hospitals—Army, Navy, and Air Force—is controlled by a joint medical regulating office at Saigon headquarters of the surgeon, U.S. Military Assistance Command, Vietnam (MACV).

Aeromedical evacuation patients have their own “hospitals” while awaiting a flight. Casualty staging units (CSU) provide complete hospital staff and facilities for airborne patients at all transfer points and aerial ports. These casualty staging units, a part of the aeromedical evacuation system, are an integral function of the local base medical facility. However, they are physically separated from the main area so that the daily routine of local patients is not disturbed by the constant movement of aeromedical evacuation patients.

Casualty staging units accomplish several functions. First, they are collection points for patients to be moved by air. Although patients do not spend much time there (the average stay is 6 to 24 hours), they can get cleaned up, change into pajamas, and rest there for the first time a little while before continuing on to their destination hospital.

While casualty staging units are normally a function of fixed base medical facilities, this is not the case in tactical operations. Casualty staging units can operate from tentage (with accommodations for 25 beds) and can be rapidly deployed to forward airheads in support of combat operations. By providing a patient holding capability and good communications with the support base, these facilities permit efficient use of backhaul cargo aircraft for aeromedical evacuation. One of these units was deployed to Khe Sanh in support of Marine operations at Hill 881 during April and May 1967, and its accomplishments earned the plaudits of the then Marine Commander, Lieutenant General L. E. Walt.

Military hospitals at Da Nang and Cam Ranh Bay now have 100-bed casualty staging units. The Tan Son Nhut facility has 85, and Clark and Yokota have 250. (The Yokota CSU is actually located at Tachikawa, and patients are bussed to the airfield at Yokota.) At Travis and Andrews, where jet overseas flights off-load patients for transport throughout the U.S., staging units now accommodate 250 and 150 patients, respectively. (A new building, which will permit a 230 transient patient load, has been requested for Andrews.)

In-country air movement of patients represents a joint effort of people at the originating hospital, the medical regulating office, and the local aeromedical evacuation unit. MACV’s medical regulating office also coordinates air movement of patients to other U.S. military hospitals is up to attending physicians, who operations.

Clinical information on patients is fed by phone or teletype from the MACV regulating office to the parent unit in Washington. Medical teams at ASMRO headquarters cross-check diagnoses with a list of beds available in specialty and other military hospitals. They decide where patients will go and send corroborating wires to MACV and receiving hospitals. How fast patients leave for destination hospitals is up to attending physicians, who decide priorities.

An “urgent” case will go immediately. But severity of an illness or injury does not automatically give a patient an “urgent” priority. The governing factor is timing—to save a life or forestall serious medical complications.

“Priority” patients, those who need prompt medical care not available locally, move within 24 hours. All other patients fall into the “routine” category with a time limit of 72 hours.

In Southeast Asia, all “routine” and most “priority” patients can be handled on regularly scheduled flights because of their frequency. But immediate movement of an “urgent” case means just that. An aircraft already in the air may be diverted, or an alert aircraft may be launched for a special flight. Air, medical, and ground crews of aeromedical units are on alert around the clock and must be able to launch a flight within an hour after a call comes in.

Within Vietnam, air evac missions are flown on C-7As, C-123s, and C-130s. The greatest number of patient moves within the theater during 1966 were by C-130s. They accounted for more than 36,000 patient moves, averaging nearly 100 patients a day over a period of one year.

The biggest job in converting cargo or passenger aircraft into airborne wards is removing cargo pallets or passenger seats and installing vertical poles to support litters. How long the job takes depends, of course, on the number of seats and litters needed for a specific flight. Starlifters have been reconfigured in as little as 25 minutes.

A control center at Hickam AFB, Hawaii, monitors intertheater aeromedical flights in the Pacific. In contrast with the “all-prop” C-118s and C-131s of the domestic force, longrange overseas flights are jet. The 500-mile-an-hour C-141 Starlifter, which flies all intertheater flights, will hold 80 litter patients or 124 ambulatory patients or a combination of both.

Not all MAC air evac flights originate in Vietnam. Some are scheduled from Clark AB in the Philippine Islands. MAC flights departing Clark take one of two routes: the northern route, which takes them to Andrews or Travis via Yokota, or the southern route with brief stops at Guam and Hickam. When serious burn cases are on board, flights continue on from Travis to the burn center at Brooke Army Hospital, San Antonio, Texas.

Scheduled flights within PACOM fall into two categories. First, there are the air evac flights that return recovered patients inbound to the theater and evacuate patients outbound on a routine basis. C-118s are used almost exclusively on these missions.

The second type of scheduled flight uses backhaul cargo aircraft, normally the C-130. The aircraft originates on its scheduled resupply mission and is reconfigured as an air evac flight for the backhaul. Sometimes the mission originates with a medical crew and equipment on board, or it may pick them up at the airfield where the patient movement mission originates. Aircraft used to support this type of mission operate on a scheduled resupply basis.

Unscheduled aeromedical evacuation flights pose the most problems, as they are normally diverted cargo missions reconfigured for air evacuation. Unscheduled evacuation flights fall in one of three categories: urgent, priority, or special. Efficient utilization of unscheduled missions requires maximum coordination among the aeromedical evacuation control centers (AECC’s), airlift operations or airlift control centers, transport squadrons, and the individual aircraft crews, as well as extensive coordination among the medical facilities involved.

All planes subject to diversion or rerouting are equipped with litter brackets and other equipment necessary for transporting patients, Each airframe has the physical capability of supporting an aeromedical evacuation requirement in the event it must move patients.

When a medical facility generates the requirement for an aeromedical evacuation flight, the lines of communication and coordination are essentially the same as for scheduled flights, regardless of the patient movement precedence. The main difference is the time permitted for completion of the mission.

Better than 65 percent of all aeromedical evacuation missions within Vietnam are unscheduled. Depending on casualties and the urgency of the movement, aircraft are often diverted from their primary function and reconfigured to meet this requirement.

Preparations for the arrival of an aeromedical aircraft are just as thorough, medically and administratively, as those for its departure. Nurses and flight surgeons from the staging unit meet each aircraft for a planeside briefing by the flight nurse and a personal check of patients who need immediate attention.

Flight-line radios can beam information on the needs of seriously ill patients to the staging unit even before the ambulances leave the aircraft. And the flight surgeon in charge may alert the main hospital to admit a patient whose condition has deteriorated in flight.

It happens infrequently, but some patients die on aeromedical aircraft. There have been six deaths on Pacific flights carrying war casualties since November 1965. When death occurs in flight or within 24 hours after arrival at a destination hospital, the senior medical attendant prepares an on-the-spot narrative report. The report and all other medical records are checked by mortality review committees at Travis, Andrews, or Scott hospitals. Autopsies are performed, the purpose of the review being to determine if aeromedical evacuation contributed to the death. As stated previously, the mortality rate is small when the total number of patients airlifted within and from Southeast Asia is compared with the mortality rates of past wars.

expert care of the patient

Before a patient boards an airplane, there are many things to be done. The load plan, for example, must be completed. All patients have designated spaces on an aeromedical aircraft. Where they go depends on their classification—litter, ambulatory, psychiatric, or non-psychiatric. Other considerations are severity of condition, need for observation, and personal comfort.

The more seriously ill patients are placed as far forward in the aircraft as possible, closer to the nurse’s station. Patients who need the most attention go in lower litter spaces, as do those with large casts, to make it easier for the flight nurse to care for them. Although use of tranquilizers has eased the problem of moving psychiatric cases, these patients still must be placed where they can be watched.

Not all patients should fly—unless, of course, local medical resources are not adequate. Physicians—Army, Navy, and Air Force —must know in what cases physiological restrictions apply. Expansion of air in body cavities, for example, is in proportion to increase in altitude. The pressure of air intracranially following a skull fracture could be hazardous. Expanding gas also can cause acute pain for the man in a recent postoperative state. And although cabin pressure at 5000 feet may be comfortable for most patients, those with anemia and heart or pulmonary problems must be watched for hypoxic symptoms.

Low humidity (3-25 percent on C-141 jets) can create difficulties for tracheostomy patients by drying mucosal surfaces and thickening tracheal secretions.

Despite bulk and weight limitations, many devices used in wards on the ground can be used just as effectively in the air. Some respirators, for example, have even been successfully miniaturized.

The “ground” doctors have help, though. Air Force flight surgeons, trained in aviation medicine, are assigned at all aeromedical departure points to assist hospital staff members.

Flight surgeons may or may not be members of the medical flight crew, but on occasion they accompany a seriously ill patient. Whenever possible, they check patients and their clinical records prior to movement by air to insure their adaptability to flight. Flight surgeons also are on hand to check patients on aircraft arriving at aeromedical transfer points.

In the air, unless a flight surgeon is on board, the flight nurse is in charge. Like the flight surgeon, she has been specially selected and trained for work on her airborne ward.

All flight nurses are graduates of a concentrated six-week course at the USAF School of Aerospace Medicine, Brooks AFB, Texas. The course covers subjects from aviation physiology and psychology to ditching and survival procedures. Physiological training also is part of the course and includes an altitude chamber flight to 43,000 feet, with exposure to rapid decompression.

The number of flight nurses on board an aircraft varies with the size of plane and patient load. Jet flights normally carry two, but domestic C-131 flights as a rule need only one.

Three or more medical technicians are on board aeromedical aircraft to help the flight nurses, the number depending on size of aircraft and patient load. The technicians also are specially trained for their airborne duties. All are graduates of Air Force medical technician programs and other courses required for those who work in aeromedical evacuation. Their training covers similar subjects but is less technical than that of the flight nurse.

the system in action

To understand better the complete picture of the aeromedical evacuation system and its related activities, let us follow a hypothetical patient moving from the battlefield to a hospital in the United States.

Corporal Smith, a 25-year-old Marine, is leading his platoon on a scouting mission just south of the Demilitarized Zone in South Vietnam. His platoon is ambushed, and a heavy fire fight follows. Smith becomes a casualty, sustaining head and shoulder wounds. In the field, he is given first aid by a Medical Corpsman, placed on a litter, and moved to a medical aid station set up to handle casualties of this and similar operations.

After giving the patient emergency treatment, the aid station arranges to have him moved by Marine or Army helicopter to a Marine Collection and Clearing Company at Hue.

At Hue, Corporal Smith receives more extensive medical treatment, and physicians there determine whether he will go further in the system or be treated at a PACOM hospital. In this case, the injuries require immediate hospitalization and further treatment. Smith’s name is forwarded to Da Nang, the nearest aeromedical evacuation control center.

It has been determined that Corporal Smith’s injuries are of an urgent nature. He must be moved immediately. Since there are no scheduled flights planned, a PACAF cargo aircraft is diverted or a plane launched to airlift the patient. In any event, the patient must be moved within two hours.

Corporal Smith is airlifted to Da Nang by a C-130. He is met at the airfield by a Marine ambulance and carried to the 350-bed Navy hospital about six miles away. He remains there until his injuries are evaluated and a determination is made as to where he will be hospitalized. If the attending physician determines that he will be fit for duty within 30 days, he will most likely remain at the Da Nang hospital. If his injuries are such that treatment will continue for up to 60 days, he will go to an offshore PACOM hospital.

When Corporal Smith is ready for transfer, the Navy hospital obtains a new destination from the Saigon office of the FEJMRO. In this case, Clark Hospital is chosen as the best facility for further treatment.

The hospital then advises the aeromedical evacuation office at Da Nang that the patient is ready for movement. The detachment arranges to have him moved on one of the scheduled flights from Da Nang to Clark. He is again transferred by ambulance to Da Nang and to the casualty staging unit. This air conditioned modern medical facility is designed as a holding station for as much as 24 hours for patients awaiting transfer on aeromedical evacuation flights.

Upon arrival at the CSU, Smith is placed in a hospital bed, provided proper hospital clothing, and prepared for air evacuation. His baggage is identified and tagged, his medical records are assembled, orders are published, and a dressed litter, including mattress, is prepared for his use in flight.

Upon arrival of his scheduled aircraft, hospital personnel place him on board, and he is flown to Clark on a PACAF aircraft. At Clark his condition is again assessed and his time to recovery estimated. If he is expected to be able to return to duty before the time limit set by DOD and CINCPAC evacuation policy, he will be held within the theater and returned to his unit upon recovery.

In this case, his injuries are such that recovery time will probably exceed the CINCPAC evacuation policy, and he must be returned to the United States. Clark Hospital telephones the ASMRO in Washington and obtains the destination.

Since Corporal Smith is from Denver, Colorado, Fitzsimmons Army General Hospital is chosen. Clark Hospital then notifies the Military Airlift Command that the patient is ready for movement, and transportation is arranged on a MAC C-141 to Travis. Smith will remain at Travis until he can be placed on a scheduled flight to Denver via the MAC domestic aeromedical evacuation system.

progress for the future

The aeromedical evacuation system is continually undergoing modifications to provide better service for the sick and wounded. Standard now on aeromedical flights is an oral hygiene kit. Disposable, spongelike oral tissue cleansers are attached to short plastic handles and dipped into a two-ounce polyethylene bottle of mouthwash (also part of the kit), to eliminate bad taste in the mouth. Low humidity in aircraft accelerates the dehydration process and causes oral problems for both patients and crews.

New litters that slide out like drawers to permit easier bedside care of patients in flight were tested on aeromedical jet flights in 1966, and the Air Force hopes they will soon be standard equipment.

“Disposables” are being suggested to replace more permanent types of aeromedical equipment, such as litter pads. Scientists at the School of Aerospace Medicine are designing one that will float, to serve as survival equipment in sea ditching. Accelerated age and impact tests soon will show what the new pad will tolerate. Also important to learn is how comfortable the pad will be for a minimum of 21 hours.

Soon to come off the drawing board is a bacteriological isolation unit. (Patients with highly contagious diseases cannot now be moved by air.) Units will be self-contained, and humidity, temperature, and oxygen will be controlled from outside.

Not on the drawing board yet but definitely on the way is an airborne intensive care unit with up-to-date equipment needed for care of the seriously ill.

Biggest boon to patients will be the medium-range jet aircraft recently authorized by DOD. The first aircraft will be used in the domestic system, but the Air Force hopes eventually to have an all-jet aeromedical force. The aircraft will have a capacity of 30 litter patients or 40 ambulatory patients or a combination of both, with the target date for delivery set for late 1968.

Plans for streamlining administration of the aeromedical evacuation system are moving along with acquisition of the all-jet airlift force. The Air Force hopes that use of computers will simplify the “who goes where and when” of aeromedical evacuation. As in the past, planners at military hospitals, domestic and overseas, will report patients for aeromedical flights on a day-to-day basis. Reports as to diagnosis, special equipment needed in flight, priority, and other medical and personal data will go to appropriate medical regulating offices and then will be fed to computers. The result will be assignment of bed space at the hospital best equipped to meet the patient’s needs. In the case of casualties returning to the U.S., computers automatically will select a specialty hospital as close as possible to the patient’s home.

Aeromedical control centers overseas and in the U.S. will use computers on a day-today basis to produce ready-made itineraries and flight plans for movement of patients to hospital assignments determined by ASMRO computers.

Aeromedical evacuation is and will continue to be a joint humanitarian effort by people of all the military services. Troops wounded in battle, felled by accident, or stricken by disease have a better chance of surviving today—often for complete recovery—than at any time in the history of warfare, thanks to a streamlined and flexible aeromedical evacuation system.

Hq United States Air Force

Contributor

Lieutenant General Kenneth E. Pletcher (M.D., Washington University) is Surgeon General, United States Air Force. He was commissioned in the Medical Reserve in 1936 and entered active duty in 1940, attending Medical Field Service School, Carlisle Barracks, Pennsylvania, and the School of Aviation Medicine, Randolph Field, Texas, where he remained two years to teach. After duty in the Office of the Air Surgeon, he served as Surgeon, 1st Air Division, Okinawa, then as Adviser in Aviation Medicine to the Central Government, China, to 1946. Other assignments have been as Instructor and Department Head, USAF School of Aviation Medicine, to 1950; student, Strategic Intelligence School; Assistant Air Attaché, London, to 1953; Surgeon, 19th Air Division, SAC, and Director, Base Medical Services, Carswell AFB, Texas, to 1957; Base Commander, RAF Burderop Park, and Commander, 7505th USAF Hospital, England, to 1959; Assistant for Life Sciences, Deputy Inspector General for Safety, Norton AFB, California, to 1961; Command Surgeon, Military Air Transport Service, to 1963; Deputy Surgeon General, USAF, to 1966; and Command Surgeon, Strategic Air Command, until his present appointment on 1 December 1967.

Disclaimer

The conclusions and opinions expressed in this document are those of the author cultivated in the freedom of expression, academic environment of Air University. They do not reflect the official position of the U.S. Government, Department of Defense, the United States Air Force or the Air University.

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