African American Officers African American Soldiers 1 The pilots Mule Rearing pilots in dress uniforms doughboys with mules Riveters gas masks

Delivery of Medical Care on the battlefield

An Introduction to the System

The United States Army began to prepare for war in 1916. Their combat doctrine stressed that they should be prepared to fight a war of movement. It was expected that all combat and support units would be organized and equipped to operate within an ever-changing battlefield environment

This concept, however, was not feasible in 1917 when the Americans arrived in Europe.  The Western Front consisted of complex and multiply-layered fortified lines that ran from the North Sea to Switzerland. However, the Americans and the Allies, as well as their German enemy, all expected that a war of movement could be achieved if these lines could be ruptured. This is exactly what happened in 1918, first to the Allies and then to the Germans.

In response to the realities of the Western Front, the Medical Department established a treatment and evacuation system that could function in both static and mobile environments. Based on their history of success in the American Civil War, and on the best practices of the French and British systems, the Department created specific units designed to provide a sequence of continuous care from the front line to the rear area in what they labelled the Theater of Operations.


Schematic Diagram of Hospitalization and Evacuation System

The Medical Department implemented their system by dividing the delivery of medical care into two commands, the Zone of the Armies and the Services of Supply. The accompanying diagram from the Medical Department’s official history illustrates the two commands. The diagram shows the Zone of the Armies was an area located up to 10 miles from enemy territory. All medical units in this area were exposed to enemy weapons and air attacks. The diagram also identifies the distances and names for medical units whose purpose was to provide the delivery of medical care that were under ‘Divisional Control’ and those that were under ‘Army Control’

At 500 to 1500 yards from the front line were the three Battalion Aid Stations of the Regimental Aid Station.  At 300 yards from the Battalion Aid Stations were the Ambulance Section Dressing Stations, operated by the infantry division’s Sanitary Train. Next, at 2 to 4 miles from the dressing stations, were the four Field Hospitals of the Sanitary Train. These medical units varied in size, but all acted within a system that progressively treated and evacuated the sick and wounded. 


Dressing Station, 26th Division, near Samogueux, Muse, October 23, 1918

If it was determined by a physician that the sick or wounded solider must receive more care, then he would be transported from the divisional medical units via a motor or horse drawn ambulance to larger and more sophisticated medical units that operated under ‘Army Control’. These higher units, as the diagram shows, were the Evacuation Hospitals located between 5 to 10 miles from the Field Hospitals. These in turn were connected to the next level of care that was provided by the large Services of Supply base hospitals via Hospital Trains.


Unloading Wounded Patients at Field Hospital No. 28, Varennes, Muse, October 2, 1918


Gillett, Mary C. The Army Medical Department 1917-1941, Center of Military History United States Army (Washington, DC, 2009)

Jaffin, Jonathan H (Colonel).  Medical Support for the American Expeditionary Forces in France during the First World War (Fort Leavenworth, 1990)

Field Operations. Volume VIII in The Medical Department of the United States Army in the World War (Washington, DC, 1925)

General Surgery, Volume XI, Section I, in The Medical Department of the United States Army in the World War (Washington, DC, 1925)

Regimental Aid Stations

3 StretcherBearerInTrenchStretcher Bearer in TrenchMedical support at the closest point to the front line was provided by physicians and Medical Corps enlisted men who were assigned to an army infantry division. These men were identified as "Medical Department personnel on duty with division troops." Their purpose was to provide medical care for the division’s infantry and artillery regiments, their machine gun and mortar battalions, the engineers, signalmen and other supporting units.

The Regimental Aid Station was staffed by 4-7 officers and 31-43 enlisted men. It would be these men who provided the first level of professionally directed care for the regiment’s sick and wounded.  However, after the infantry divisions were reorganized in August, 1918, the Regimental Aid Station personnel were disbursed to provide immediate medical support to the regiment’s infantry battalions. This resulted in the creation of three Battalion Aid Stations.

Each station was intended to support four infantry companies by locating its station to the rear of the battalion and by placing two Medical Corps enlisted men with each infantry company to man a Company Aid Post. These eight men were trained and supervised by the physician assigned to the Battalion Aid Station. The Regimental Aid Station’s role now became a headquarters to command the battalion stations and if needed could combine the dispersed stations back into one unit, if needed.

1 Aid StationAid Station, 7th Artillery Regiment, 1st Division, Serevillers, July 5, 1918The Company Aid Post was sited in a sheltered location very near the front line if the unit was garrisoning a trench system. However, if the company was out of its protected position making an assault or in retreat the post would move and establish a succession of posts to provide emergency medical care.

2 FieldDressingIndividual Field Wound DressingIt was expected that the initial treatment of a man’s wounds would begin with his own application of his first-aid dressing. To do this each man was provided with two gauze bandages (4”x84”), two gauze compresses (3 ½” x 3 ½ “), two safety pins and was instructed on how to apply the dressing by one of the physicians assigned to his battalion.  The purposes of this dressing was to protect the wound from further trauma, prevent loss of blood, and reduce the possibility of secondary infection and to give the man some physical and psychological comfort.  If a wounded soldier could not care for himself, the dressing may have been applied by a comrade.   More likely, this was done by stretcher bearers or by company aid post personnel,   who were trained in how to apply field dressings, control hemorrhage, splint fractures and to protect the wounded from gas.

8 AidStationBattalion Aid Station, 101st Infantry, 26th Division, Bois de la VoisogneAbout 40% of the wounded men were able to walk to the rear. The remainder would need to be carried by regimental stretcher bearers, who were men assigned from the battalion, to the next level of care which was the Battalion Aid Station where they would be seen by a physician. The locating, marking, gathering and directing of the sick and wounded to the next level of care would have been an important patient management task performed by the two men assigned to the Company Aid Post.

The Battalion Aid Station was centrally located at 500 to 1000 yards behind the infantry companies in a building, dugout or specially constructed shelter. Its location was carefully selected because it had to be easily reached from the front by foot and on a road, if possible, to allow ambulances to pick up the patients for transport to their next level of care.

An aid station’s site could be anything from a hasty shelter to set of above or below ground rooms constructed over time that could treat from 12 to 30 patients for their injuries, project them from further harm, hold them for evacuation, plus store medical supplies for the station and company aid posts.  The Battalion Aid Station was staffed by one medical officer, four to six Medical Corps enlisted men, two runners and one or more stretcher bearer squads.

Initial treatment was limited to physician-directed emergency care, and might include:

  • Controlling hemorrhage
  • Application or readjustment of field dressings and splints
  • Administration of the anti-tetanus serum and morphine for pain
  • Treatment for gas injuries
  • Anti-shock treatments such as warmth, hot food and drinks

The first step in a long process of sorting the sick and wounded began here with the filling out of the patient’s field card  that noted whether he was:

  • Very slightly wounded but able to return to the line
  • Slightly wounded and requires evacuation
  • Seriously wounded
  • Patient with fractures
  • Severely wounded with attendant shock
  • Gassed patient
  • Psychoneurotic
  • Sick

If the patient was slightly wounded or not seriously sick he would be retained at battalion level. More seriously-wounded were evacuated. Those to be evacuated, included those with serious wounds or fractures, were likely to receive the attentions of the physician whose treatment might include:

  • Painting around the wound with iodine
  • Injection of 500 units of the anti-tetanus serum
  • One-fourth grain of morphine for pain to slightly to seriously wounded
  • Control of hemorrhage through ligature, hemostats or a tourniquet
  • Immobilization of fractures with wooden splints or the Thomas Splint
  • Shock treatment such as blankets and hot drinks

6 AidStationRegimental Aid Station, 29th Infantry, near CantignyPhysician directed treatment was designed to stabilize the man and prepare him for transport.  This might be the divisional dressing station or field hospital.  At the same time the stabilizing treatment was given the staff coordinated his evacuation with the personnel of the next level of care: the ambulance company and its dressing station.

Given that the aid station could not provide surgical procedures; retain patients for any length of time; were subject to enemy artillery fire; and were constantly receiving new patients it was essential to evacuate their patients as soon as possible. This was especially important due to the risk that the wounded could develop a life, or limb, threatening gas-gangrene infection if he did not receive a surgical intervention within 12 hours of his wounding. 

Timely evacuation was a challenge due to the weather, terrain, enemy fire, how to move the patient and the patient’s condition. Weather and terrain were variables that could not be controlled. The threat from enemy fire could be mitigated by a night evacuation.The means of evacuation, by stretcher bearers, wheeled stretcher cart or ambulance and preparing the patient for movement were variables that the station’s staff focused on.


Jaffin, Colonel Jonathan H. Medical support for the American Expeditionary Forces in France during the First World War (Fort Leavenworth 1990)

Volume VIII, Field Operations, The Medical Department of the United States Army in the World War (Washington, 1925)

Volume XI, Section I, General Surgery, The Medical Department of the United States Army in the World War (Washington, 1925) 

Delivery of Medical Care on the Battlefield

Ambulance Section

1 Aid StationAid Station, First Division, Missy-aux-Bois
After receiving emergency care from the medical corps personnel at the battalion or regimental aid station, the sick and wounded were evacuated to the next phase of physician-directed care provided by the division's sanitary train.  This 950 man unit consisted of:

  • One headquarters
  • One ambulance section that was comprised of a headquarters and four companies
  • One Field hospital section that consisted of a headquarters and four field hospitals
  • Eight camp infirmaries
  • One divisional medical supply unit

The word ‘train’ is unique to the era. It identifies the support units assigned to an infantry division of which there four trains: ammunition, supply, engineer and sanitary. All used horse drawn wagons or motor vehicles in order to be mobile and to support the entire division’s personnel. The purpose of the sanitary train was to provide medical care to the division through its units.

OnBattlefield 3 figure 2The deployment of the 82nd Infantry Division’s Sanitary Train in September 1918 for the St. Mihiel offensive illustrates how a train’s units were placed in order to support the division. The map shows that at the start of the battle one unit, Ambulance Company 327 (AC 327) was placed at Dieulouard with Field Hospital 328. To the south of their position AC 325 and 328 were on alert and in reserve at Millery with the other three field hospitals, while AC 326 was further to the rear at Marbache. As the battle progressed AC 327 was moved north to Blenod on September 7th and to Norray on September 16th. The shift in locations illustrates how the ambulance company maintained contact with the moving battalion aid stations in order to provide a timely evacuation of patients to a field hospital.

The ambulance section’s four companies had a total of 48 ambulances that were distributed evenly among the four companies. One company was equipped with 12 horse drawn ambulances, while the other three had motor ambulances. By 1918 experience had proved that the motor ambulance was the most effective means to evacuate men from the front. This meant that the horse drawn company was held in reserve because although they could negotiate terrain that was impassable to motor vehicles they presented a large target, were slow and the horses quickly tired in contrast to motor vehicles.3 collecting point USCollecting point, 3rd Division, Nantillois, Muse

The ambulance company was divided into two sections. One operated the dressing station while the other collected, coordinated and moved patients from the battalions to the dressing station and then on to a field hospital. Because the combat zone was so dangerous, evacuation from the front for the first 500 to 1500 yards was on foot by either the walking wounded or by litter bearer squads sent forward from the ambulance company. The destination of the wounded was to a collecting point where vehicles could be safely assembled to load patients.The other section of the ambulance company manned a dressing station that was at about 300 yards form the battalion aid stations which would place it at about 800 to 1800 yards from the front line. It was staffed by up to 5 officers and 25 men and was sited on a road, if possible, and housed in a dug out, cellar, building or tents. The sanitary train could deploy up to four dressing stations but in practice it was one, if the division’s front was narrow or more if wider, while one was held in reserve. If the division was engaged in mobile warfare the dressing station might be divided in order to create an advanced dressing station staffed by 1 officer and 15 men closer to the front while the main dressing station with its larger staff was further to the rear.

4 DressingStationDressing Station, LahayvilleThe purpose of both dressing stations was similar to the battalion aid station in that it continued to provide emergency medical care such as:

  • Arresting hemorrhage
  • Inspecting and readjusting the patient’s dressings and splints
  • Administering morphine and the anti-tetanus serum
  • Treating for shock and gas injuries

At this level more sophisticated treatment could be carried out than was possible at a battalion aid station.  This might include treatment for shock and gas or even surgical procedures such as closing an aspirating chest wound or controlling hemorrhage through ligature and packing the wound.  Patient management was a primary concern for the staff at this phase of care. The first evidence of this was the attention given to the design of a continuous system of evacuation by ambulances from the battlefield as performed by the ambulance company. The second was the continuation of stabilizing the patient at the dressing station for further evacuation and the first attempt at the  classification of patients in order to direct them to the right care.

5 AidStationEntranceDressing Station, Ambulance Co 111, 28th Division, St Gilles
The dressing station addressed these tasks by organizing itself into departments
so as to efficiently manage the care of patients through the following departments:

  • Receiving and forwarding
  • Dressing
  • Orthopedics
  • Gas

The creation of these departments indicates the first step toward placing patients requiring specialized expertise,  such as orthopedic and gas cases, with a staff that had experience in treating these types of injuries.  The receiving and forwarding department was tasked to unload, sort and classify new patients. It was supervised by a medical officer who examined them and determined who should be returned to their unit, who needed immediate attention from the dressing, orthopedic or gas departments and who and when should be evacuated to the next level of care that would be the ‘Triage’ operated by one of the sanitary train’s field hospitals.6 DressingStationLahayvilleDressing Station, Lahayville

Sources for Ambulance Section

Jaffin, Colonel Jonathan H. Medical support for the American Expeditionary Forces in France during the First World War (Fort Leavenworth 1990)

 Volume VIII, Field Operations, The Medical Department of the United States Army in the World War (Washington, 1925)

Volume XI, Section I, General Surgery, The Medical Department of the United States Army in the World War (Washington, 1925)

Delivery of Medical Care on the Battlefield

Triage and the Field Hospital Section

TriageTriage, 42nd Division, near Sieppes

In 1918, the US adopted the French method of "triage".   This was found to be an effective method to sort, classify, and distribute the sick and wounded during the first stage of the treatment and evacuation of soldiers from the battlefield.   The decision to explore the French method meant it would have to be assigned to the field hospital section because it was the only unit in the sanitary train large enough to perform the task. This section, comprising four identical field hospitals, was staffed by a total of 25 officers and 337 men. Each hospital could accommodate 216 patients.  All were equipped to be mobile so as to maintain contact with the forward medical units that they supported.  In early to mid-1918 the static combat environment permitted these four hospitals to be grouped together for greater efficiency. They were placed at 2 to 4 miles on a road that linked them to the dressing sections of the ambulance sections, and to the next level medical treatment in the rear, the evacuation hospitals.

Field Hospitals 79 Div FranceField Hospitals, 314 and 316, 79 DivisionThe practice of deploying four hospitals to perform the same role changed in May 1918 when the 1st Infantry Division’s field hospital section at the Battle of Cantigny experimented with assigning a specific type of patient to three of their hospitals that they identified as:

  • Wounded and gassed
  • Sick
  • Skin and venereal diseases

The fourth hospital was tasked to be the medical reserve and a convalescent camp. At the same time the concept of ‘triage’ was explored with the technique assigned to the hospital that received the wounded and gassed.  The concept of designating a type of patient to each field hospital was quickly adopted by the other field hospitals operating with the infantry divisions. In practice, however, each division’s field hospital section was free to establish what classification worked best for them.

 OnBattlefield 3 figure 2Just how "triage" operated with multiple field hospitals and ambulance companies is illustrated in the map, showing deployment of the 82nd Infantry Division’s Sanitary Train in September 1918 for the St. Mihiel offensive. At the start of the operation Field Hospital 328 was designated as the division’s ‘triage’ and was located at Dieulouard. It remained at that location throughout the battle.  It began receiving casualties eight hours after the start of the offensive on September 12th. At Millery, further south, the 325th Field Hospital was designated to receive the sick, the 326th the gassed and the 327th the wounded.  This illustration also indicates the preferred site for the division’s field hospitals. Although each had tents, the preferred location was in a village. Such a site was likely to have intact buildings that could provide better shelter, a water supply, sources of fuel and perhaps even electricity.

The field hospital section was the last point for a man to receive treatment from the division medical units.  Arrival and treatment at one of these hospitals did not mean the patient would be evacuated to the next level of treatment, such as an evacuation hospital. If a patient did not require prolonged care and was likely to recover within 14 days he was retained at one of the field hospitals designated for his condition.  This decision illustrates the value of ‘triage’ as a method to sort, classify and determine who should be evacuated and to where and who should not be transported to the next level of care. If a patient could recover within the specified days then his contribution to the infantry division was not lost.

An example that illustrates the diagnostic procedure for a man who was classified as a possible case of ‘war neurosis’. At  "triage" this patient would be examined by the division psychiatrist to determine the cause and severity of his condition.  This examination, classification and a recommended treatment led to 65% of the cases seen at the division level to be retained and 35% to be evacuated to a neurological hospital.  The six possible diagnostic classifications he used were:

  • Shell fright
  • Gas fright
  • Hysteria
  • Mental and or physical fatigue
  • Malingering
  • Cowardice

Triage 79th Division MoutreullTriage station, 79th Division, MoutreullSorting, classification and distribution done at a "triage" station required a skilled team to determine who was transportable and who needed to be retained until they were ready to be moved. Ideally the team had a thorough knowledge of medicine, surgery and human nature, and was usually headed by a senior medical officer. Their evaluations had to be complete and unhurried but quick enough to prevent congestion caused by the arrival of new patients.  Often, "complete" and "quick enough" were at odds, and the system could be overwhelmed by a large number of casualties.

The essential sorting and classifications at the "triage" focused on identifying those who were wounded, gassed or were medical cases, and who were transportable or not. In some "triage" units the mission was to sort and distribute to the nearest hospitals according to the medical diagnosis. In others there was a continuation of emergency medical care but with more sophisticated treatment as compared with the ambulance company dressing stations.

FH 1 2nd Div Field Hospital 1, 2nd Division, Benzu-leGueryThe treatment for shock was a top priority whether given at the "triage" or at the field hospital for the wounded and consisted of:

  • Removal of wet clothing
  • Warming through blankets, stoves and warming tables
  • Hot drinks and food
  • Morphine for pain
  • Adjustment of splints and bandages to reduce pain
  • Intravenous saline solution
  • Blood transfusion from matched donors

Prior to receiving treatment for shock the patient would have been seen in the receiving department of the ‘triage’ or hospital for the wounded. His condition would determine whether he would be routed to the dressing, shock or operating departments. If treatment for shock was required he would be held there until his condition permitted either evacuation or treatment by the operating department’s team.

FH 13 Vendeuil CapryField Hospital 13, Vendeuil-CapryThe operating teams focused on the control of hemorrhage and stabilization of broken bones.  If time permitted, wound debridement including removal of foreign material could be done.  All surgical work was intended to be life-saving rather than definitive.  The intent was to prepare the patient for evacuation to a rear area hospital where more time-consuming and definitive operations could be done.

At the hospital designated for the treatment of gas injuries the patient’s clothes were removed and he was bathed to remove possible contamination.  This was followed by an appropriate treatment for the cause of his injury, depending on the nature of the gas injury.  Mustard gas, for example, produced serious skin blistering, while chlorine gas caused lung inflammation.  

Medical treatment as described at this level of physician directed care was constrained by the reality that only essential emergency procedures could be performed. It was imperative that this lifesaving care be matched by the need to maintain the best patient management system possible. Therefore, the primary mission for the staff of the ambulance and field hospital sections was first to save lives and then to prepare patients for evacuation to the next level of treatment, either an evacuation hospital or a base hospital. Evacuating a Patient FH 14 MontreiulEvacuating a Patient, Field Hospital 14, Montreull


 Jaffin, Colonel Jonathan H. Medical support for the American Expeditionary Forces in France during the First World War (Fort Leavenworth 1990)

Volume VIII, Field Operations, The Medical Department of the United States Army in the World War (Washington, 1925)

Volume XI, Section I, General Surgery, The Medical Department of the United States Army in the World War (Washington, 1925)

Delivery of Medical Care on the Battlefield

Corps and Army Levels

The sick and wounded who required more medical care, as identified by the physicians of the field hospitals, were transported to a hospital located at the next level of the Medical Department’s system for treatment and evacuation.  As seen in the diagram below, this consisted of hospitals located within the command and control of the corps and armies. These facilities were located 5 to 10 miles from the field hospitals.  Patients were generally transported by motor ambulances.Evacuation HospitalEvacuation Hospital No 1, Under Canvas  

This level was the intersection between the forward area medical units and the rear area’s base hospitals that were reached via hospital trains. This level was one of the most complex layers of patient care in the system. It is here that the sick and wounded received more sophisticated treatment, including both life-saving and definitive surgery, that could not be performed by the division’s field hospitals.

The transition from the division-level medical units to the corps-army facilities, and subsequently on to the base hospitals, was carried out by a detailed and comprehensive medical plan.  These plans were made in advance of an offensive operation and were situational,  Medical units that were assembled were done so to meet the anticipated casualties. At the conclusion of the battle they were reassigned to a new location for the next offensive.  The old mililtary adage still applied:  "No plan survives contact with the enemy."  At best, the plans served to bring all needed medical assets to bear in the area of the battle.  But extensive adaptation and improvisation was always required.

St Mihel Operation PlanAn illustration of plans for an operation was the one prepared by the First Army’s Chief Surgeon Colonel Alexander Stark for the St. Mihiel Operation from September 12-16, 1918. The accompanying map shows the medical units with their locations on the eve of the battle.  For this offensive the units were at between 9 to 15 miles behind the front line and although out of range of all but long range guns, although they were vulnerable to attack from German aircraft.  The figure shows placement of the following types of medical units:

  • Evacuation ambulance companies: 9
  • Corps level ambulance companies: 4
  • Corps level field hospitals: 4
  • Medical supply depots: 3
  • Gas hospitals: 2
  • Contagious disease hospital: 1
  • Neurological hospitals: 2
  • Mobile hospitals: 5
  • American Red Cross hospital: 1
  • Evacuation hospitals: 10
  • Base hospitals: 2

This list also illustrates how by late 1918 the Medical Department was designating certain hospitals to receive specific patients, such as gas, contagious diseases and neurological cases. The department found that by establishing hospitals for one type of patient at this level they could concentrate specialists with experience in treating these cases and thus improve their delivery of care.

Mobil Hospital 2
Mobil Hospital 2, Loaded on Trucks
The five mobile hospitals illustrates the department’s experimentation with a new type of unit. It was based on French Auto-chir and was designed to deliver lifesaving surgery close to the front. This small mobile hospital was a dedicated surgical unit that possessed specialized equipment and vehicles, so it could be rapidly deployed where needed. This new unit was not fully integrated into the system for delivering care on the battlefield and so by the end of the war the twelve units that were created treated only 1% of the wounded.  In later wars, and currently, mobile hospitals and forward surgical teams are important components of the overall medical effort, with the difference that they are now fully integrated into the casualty care system..

By contrast, the ten evacuation hospitals were fully integrated.  They were tasked to receive the majority of patients evacuated from the field hospitals. These units were so essential to the task of delivering life-saving surgery, and in such short supply, that base hospitals 45, 51 and a Red Cross hospital were designated to function as evacuation hospitals.

The map also shows where the units were placed. The largest clusters were at the rear of I and IV Corps, which were to carry the main attack. It was anticipated that this action would result in 33,000 casualties over four days. And because these hospitals were not designed to retain their patients for a full recovery, they were placed on rail lines, such as at Toul, so their patients could be evacuated within fourteen days to the next level and final stage of care at a base hospital in the rear area, under the command of Services and Supply..

Sources: Corps and Army Levels

Jaffin, Colonel Jonathan H. Medical support for the American Expeditionary Forces in France during the First World War (Fort Leavenworth 1990)

Volume VIII, Field Operations, The Medical Department of the United States Army in the World War (Washington, 1925)

Volume XI, Section I, General Surgery, The Medical Department of the United States Army in the World War (Washington, 1925)

Delivery of Medical Care on the Battlefield

Evacuation Hospitals

The system for the delivery of medical care on the battlefield was based on the premise of providing a process of progressive treatment and evacuation. In practice this meant the sick and wounded would receive care from the infantry division’s medical units, such as aid posts, dressing stations and field hospitals. The purpose at each stage was to provide enough treatment in order to stabilize the patient and prepare him for transportation to the next level of medical care: the evacuation hospital. The system diagram below illustrates how this progressive sequence of treatment and evacuation led from medical units near the front line to the evacuation hospitals at the corps and army levels and then on to base hospitals in the rear, via hospital trains.SystemDiagram of Hospitalization and Evacuation System

The purpose of the evacuation hospital, as first conceived of in 1916, was to support the infantry division field hospitals by receiving their patients when they moved to new locations. However, as it turned out this would not be their role when deployed to France. What changed their medical mission was the experience acquired by the department in the summer of 1917. It was discovered that the intended purpose of the field hospital to be the “emergency hospital for the battlefield” failed because the unit was too small, to close to the front line and was expected to be mobile. The department recognized that instead of performing life saving surgery they had become a “magnified and improved dressing station rather than a hospital.” What was needed was a medical unit equivalent to the British Army’s Casualty Clearing Station that could treat up to 1000 patients per day.Casualty Clearing StationNo. 3 Casualty Clearing Station, July, 1916 (British)

The evacuation hospital evolved over the next year into a larger and more capable hospital unit.  When developed in 1916 the evacuation hospital was planned to care for 432 patients through its staff of 16 medical officers and 179 men. Two evacuation hospitals were to be allocated to an infantry division. Although supplies were available to equip twenty-two hospitals, the army did not have personnel to staff them. By 1917 it was recognized hat they must solve how to deliver life saving surgery on the battlefield.  The department re-thought the purpose and size of this new unit. It would be enlarged to treat up to1000 patients through a larger staff of 34 medical officers, 237 enlisted men and a complement of female nurses.

Although the size of evacuation hospitals varied, their function, general layout and location remained consistent throughout the war. Their purpose was to provide “with great rapidity” the best possible surgical care.  But this was constrained by the number of casualties they could receive per day. In order to prevent congestion and over-loading of these hospitals, the army’s chief surgeon prepared a plan that deployed these hospitals and other medical units for each offensive. In the operations plan, he clustered the hospitals so they could support each other.  Sites were chosen to facilitate both reception and treatment of patients and eventual evacuation to the rear area base hospitals. In practice, these hospitals were relay stations that provided significant treatment but did not retain patients any longer than necessary. 

Evacuation hospitals were expected to be mobile, which meant they were housed in tents. "Mobile" was a relative concept.  These units were barely mobile, and had little to no organic transport capabilities.  To move one hospital unit required ninety 3-ton trucks or 30 rail cars. If possible they were placed in towns which provided buildings and access to fuel and water. They were located at 9 to 15 miles from the front on roads that linked them to forward medical units and on rail lines to connect them to base hospitals further in the rear area.6 figure 4Plan of Evacuation Hospitals 6 and 7, Souilly

The hospital’s layout was designed to quickly treat a large number of admissions. The ground plan shown was for Evacuation Hospitals 6 and 7, located in 1918 at Souilly.  The receiving rooms and evacuation wards were adjacent to a road and rail lines, to facilitate patient arrival and evacuation. In the center were the operating rooms, x-ray rooms, and adjacent hospital wards.  These hospitals were organized into two services, administrative and medical. The former dealt with records, supply, personnel and administrative matters while the medical provided patient care as directed by the Chief of Surgical Service and Chief of Medical Service.

The Chief of Surgical Service supervised the:

  • Receiving room
  • Dressing room
  • X-ray room
  • Pre-operative ward
  • Shock ward
  • Operating room
  • Post-operative ward
  • Evacuation ward

 Receiving Room, Evacuation HospitalReceiving Room, Evacuation HospitalThe Chief of Medical Service supervised the medical and gas wards and assisted the Chief of Surgical Service in the receiving ward.

The process of sorting patients began with their examination upon arrival at a receiving room which would determine where the patient should be routed. At this point an important decision would be: Should he receive an operation or could it be delayed until he arrived at a base hospital? For example, a small perforated wound, flesh wound, or small bone fracture made one eligible for re-dressing in the dressing room and on to the evacuation ward to await a hospital train. This decision was likely if 1000 casualties were received in a day. These injuries were not deemed as serious as head, chest, and abdominal wounds, fractured femurs, head injuries, or multiple injuries.

X-ray of shoulder, with bulletX-ray of Shoulder, with BulletThe surgical service consisted of five wards and three rooms.  There were the pre-operative ward, x-ray room, shock ward, operating room, post-operative ward. These were all close together, as shown by the diagram above, to reduce the distance a patient was carried and to efficiently use staff and resources.

 The pre-operative ward prepared patients for surgery through another examination, undressing, bathing, morphine, shock prevention and sorting them into head, chest, abdominal, shock and fracture cases. If a patient was in shock or on the verge of it he was moved to the shock ward for resuscitation.  If an x-ray was ordered, he was transported to that room.

 Operating Room Evacuation Hospital 2OR, Evacuation Hospital 2, BaccaratThe operating room was staffed by four teams using eight tables. Each team consisted of two surgeons, one anesthetist and two nurses.  An experienced team could perform 35 to 40 operations per twelve-hour shift. By mid-1918 it was common during a major offensive operation for these teams to be augmented from quiet evacuation and base hospitals, expamding the service to as many as fourteen teams.

Surgical operations addressed different types and severity of injuries. A laparotomy was performed for abdominal wounds. Thoracotomies could be done for chest wounds, but simple placement of chest tube was the most common treatment.  Wounds caused by bullets and shell fragments required debridement of devitalized tissue and foreign bodies. Debridement helped to prevent infection, especially gas gangrene caused by anaerobic bacteria. The wound, if there was a possibility of infection, was left open and packed or wrapped with gauze soaked in saline or Dakin's solution, in anticipation of using the Carrel-Dakin system to prevent or control infection (See Wounds and Injuries).Debridement of a WoundDebridement of a Wound

Fractures were set as well as repairs to the knee or elbow. If a limb was too badly damaged, it was amputated. Even though radiology was only in its second decade of existance, x-rays were very valuable in treating extremity and joint injuries.Fracture Ward, Evacuation HospitalFracture Ward of an Evacuation Hospital

Head wounds were a challenge because they required neurosurgical skills that might not be present.  If an operation was performed it prevented an immediate evacuation. Therefore, the Chief of Surgical Service might recommend a delay and evacuate the patient to a base hospital.

Upon completion the surgeon recorded his findings, the procedure and whether the patient should be ‘detained’ or ‘evacuated’. Both categories were moved to the post-operative ward for recovery. If a patient was detained he was then moved to an appropriate ward of similar injuries. All cases, however, were not retained any longer than necessary which on average was 10 to 14 days.  If a patient was identified for evacuation upon recovery he was moved to the evacuation ward to join those from the receiving ward or dressing room. Here he was prepared for evacuation by being classified as a sitting or stretcher patient and whether he was a surgical, medical, infectious disease or psychiatric case.

Recovery ward of evacuation hospitalRecovery Ward of an Evacuation HospitalAt this point the soldier passed to the next level of care, which was base hospitals in the rear areas, often via a hospital train. The coordination of this transfer was essential for the success of the entire patient management system designed by the Medical Department. It was entrusted to the Chief of Surgical Service who arranged with the army’s Regulating Officer for a hospital train to evacuate patients to their final destinations at the base hospitals.

Sources for Evacuation Hospitals

 Jaffin, Colonel Jonathan H. Medical support for the American Expeditionary Forces in France during the First World War (Fort Leavenworth 1990)

Surgery in progress in an operating theatre suite at No 3 Casualty Clearing Station, July 1916, Creator Canadian Official photographer H E Knobel, Catalogue number co 157, Part of Canadian First World War Official Exchange Collection, Imperial War Museum, London

 Volume VIII, Field Operations, The Medical Department of the United States Army in the World War (Washington, 1925)

Volume XI, Section I, General Surgery, The Medical Department of the United States Army in the World War (Washington, 1925)

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