U.S. Army Medical Department, Office of Medical History
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France, June 12, 1918.

The following information will be given the widest possible circulation among the medical officers of the American Expeditionary Forces. Each medical officer should possess and keep at hand a copy of this circular: "Short résumé of the symptoms and treatment of poisoning by irritant gases.

The gases which have been met with most commonly up to the present time may be divided schematically into three classes:
(1) Suffocative gases, which exercise their main effect on the lung tissue (chlorine, phosgene, diphosgene, chloropicrin).
(2) Vesicants, the prime effect of which is exercised upon the skin conjunctive and upper air passages (dichlorethylsulphide, mustard gas or yperite).
(3) Pure lacrymatory gases (xylyl-bromide).

Gas may be liberated from cylinders in clouds, a method not now commonly employed, or from shells. "The general aim of the enemy in the present use of gas shells is to fire simultaneously shells of different types, some of which will cause so much sensory irritation that the man will discard his respirator and then become vulnerable to lethal shells, phosgene, and similar substances. Owing to this mixture of shells the symptoms reported by patients are often very confusing."

NOTE.- Much of this material has been extracted from the valuable reports of the British chemical warfare medical committee and from the excellent report of Lieut. Col. H. L. Gilchrist, issued by the office of the chief of the gas service, American Expeditionary Forces, March 15, 1918.

For this purpose several arsenical compounds have been tried.



Suffocative gases, which are relatively nonirritative oil inhalation in the concentrations ordinarily used, induce some hours after their entrance all intense edema of the lungs. Through the great outpouring of fluid into the lung tissue the patient drowns ill his own serum; the blood becomes greatly condensed and viscous; there is marked polycythemia; the capillary flow is obstructed; thromboses are not uncommon, a greatly increased strain is put upon the right heart; the patient suffers from intense oxygen want.


"The immediate effects of irritation of the eyes may be prominent at first, but as a rule quickly pass off; within 3 to 12 hours after exposure to the gas the main symptoms, asphyxia and prostration, due to affection of the lung alveoli and accumulation of fluid in them, appear. In this state the patient's respiration is rapid and usually accompanied by pain (often intense) in the chest; there may be fits of coughing, but the amount of expectoration is very variable, being profuse in some cases and very scanty in others; in the more severe cases the patient is restless and anxious, or may be semicomatose, with muttering delirium. Therefore many patients will be unable to give a definite account of their symptomns, as loss of memory of immediate events may last for several days. Patients with severe pulmonary edema fall into two groups.

a Copy on file, Historical Division, S. G. O.


"(a) Those with definite venous engorgement. In these the face is congested, the lips blue, and the superficial veins of the face may be visibly distended. There is true hyperpnea; i. e., the breathing is not increased in frequency but the actual amount of air reaching the lungs is greater than normal. The pulse is full and of good tension, and the rate is not often much above 100.
"(b) Those with collapse. In these the face is pale and the lips of a leaden color. The breathing is shallow, so that there is but little true hyperpnea. The pulse is rapid (130 to 140) and weak.

"In patients who recover, the edema fluid is absorbed within a few days; in some cases signs of bronchitis or bronchopneumonia, due to a secondary infection, persist for some time, but in most cases the lung returns to a condition which is normal except for the presence of some disruptive emphysema. In consequence, however, of the edema of the lungs during the early stage, deficient oxygenation of the blood occurs, unless prevented by the administration of oxygen. The deficient oxygenation gives rise to widespread temporary injury in the various systems.

"2. Vesicants.- The only one hitherto employed is dichlorethylsulphide, an oily liquid used in shells, and scattered from them on the ground, where it slowly evaporates. This not only attacks those in the immediate vicinity of the shell burst, but may affect those who may walk over the contaminated ground later. The fluid may be spattered also on clothing, shell casings, rifles, etc., and may thus become effective through direct contamination of the skin.

"The main action of this group is an irritant one on the skin, eyes, and respiratory passages.

"Special symptoms.- (a) Early.-These are insignificant, nothing being noticed immediately except a smell reminiscent of mustard, from which the gas derives its name (mustard gas). A soldier may not realize for many hours that he has been exposed to gas, until the more important delayed symptoms develop.
"(b) Delayed.- These are the principal symptoms of this group and appear 3 to 24 hours after being gassed. They occur usually in the following order, and approximately after the intervals stated.
"(i) Conjunctivitis (3 hours). This rapidly becomes very acute, and is accompanied by intense photophobia, and swelling of the lids, which may cause closure of the eyes for days.
"(ii) Vomiting and epigastric pain (4 to 8 hours). These symptoms appear together, as a rule, and are apt to be persistent and intractable.
"(iii) Burns (12 hours). Widespread erythema with local vesication occurs, going on to definite burns. The commonest sites are the axillae, genitals, and back, but no area may be exempt. The affected surfaces frequently develop very marked pigmentation. Deep burns sometimes occur when the liquid itself comes into contact with the clothes or skin.
"(iv) Laryngitis, pharyngitis, tracheitis, and bronchitis (24 to 48 hours). These are the most dangerous symptoms. The degree and extent of the lesion may vary from a simple irritation of the surface to an ulceration of the mucous membrane of the whole passages, followed by infection of the raw surfaces. These conditions may be so extensive and severe as to cause deathlby themselves or in consequence of the development of bronchopneumonia.

"In a certain number of cases with severe involvement of the respiratory organs, which recover, there has evidently been some interference with the proper oxygenation of the blood, which may give rise'eventually to symptoms resembling the after effects of the suffocative gases. * * *

"When a soldier is protected by the respirator, the respiratory and eye symptoms are absent or slight."



The grave symptoms here are due mainly to the intense pulmilonary edema. The conditions which we have to combat are essentially: (a) Oxygen want; (b) condensation of blood; (c) overburdening of the right heart.

Our main aims are: (a) Rest; (b) warmth; (c) oxygen; (d) bleeding;

(a) Rest.-Protect the patient from all unnecessary physical effort in order to reduce the oxygen need. Do not disturb him at thie advanced aid station by questioning; his life may depend on the care with which lie is handled in the early stage.


All the gassed should be stretcher cases.- Small oxygen tubes, if available, should be carried in each ambulance in the proportion of one to each stretcher case, and exchanged at the evacuation hospital for freshly filled tubes; these can of course be used only when the ambulance has passed out of the gassed area.

Give the patient fresh air. Do not close the ambulance too tightly unless it be very dusty.

(b) Warmth.- Warmth is important. Cold and shivering mean an increased production of CO2 and an increased demand for oxygen. The clothes must be removed at the earliest moment, for they hold gas and may be dangerous not only to the patient but to those about him; warm covering must, however, be provided.
(c) Oxygen.- The administration of oxygen in all dyspneic, cyanotic patients is of vital importance. The administration should be so nearly continuous as possible up to the point of the disappearance of the cyanosis, and should be continually repeated whenever the demand is evident.
(d) Bleeding.- In patients who are cyanotic and show engorgement of the venous system, bleeding is indicated. By venesection we combat-
(1) Edema of the lungs.
(2) The condensation of the blood; for with the abstraction of the polycythemic blood, fluid is drawn from the lungs and the tissues, and the circulatory medium becomes less viscous.
(3) The overburdening of the right heart.

The bleeding should be early and free from 2 to 600 c.c.

Bleeding is inadvisable
, nay dangerous, in the patient who is pale and gray and in collapse.

If the heart's action be rapid or feeble, bleeding may be preceded by an intramuscular injection, 15 minutes before the venesection, of one-fourth milligram (1/250 grain) Digitaline cristalisee Nativelle. This may, if necessary, be repeated once or twice in the next 24 hours, and continued later by the mouth if necessary.

In the early stages, during the period of distressing restlessness and agitation and pulmonary edema, morphia may be necessary. Its action as a respiratory depressent is believed by some to be dangerous; and the administration of oxygen, if it suffices, is the safest and best means of quieting the agitation. Where the distress and physical effort associated with the struggles of the patient are great, morphia 0.016 (¼ grain), hypodermically, may be demanded, but at the same time it should be remembered that in collapse, dulling of the respiratory center may turn the scale against the patient.


Oxygen is here the main aim, and the administration should be practically continuous.

Never bleed these patients
. Bleed only those with venous congestion.

Rest, warmth, and oxygen are the mainstays of treatment. Atropine and adrenaline are contraindicated. These drugs place an increased strain on the heart. It is best to abstain from intravenous salt solution injections. The fluid introduced puts an extra burden on the heart, is soon absorbed into the tissues, and may increase the pulmonary edema. In grave cardiac weakness, preparations of camphor or caffeine may be given hypodermically, and digitalis may be indicated, according to the nature of the case.


In any patient who has had pulmonary edema it may, within the first few days, recur on slight exertion or even without apparent cause, and if there have been any definite symptoms of edema of the lungs the patient should be kept in bed for a week.

Smoking should be absolutely prohibited
, and convalescents should not be allowed to smoke in the ward in which these patients lie.

Patients whose symptoms have been mild should, if possible, be plut on graduated exercises as soon as they are out of bed, and under military discipline as soon as possible. Mild cases should be back in the line in about two weeks. Severe cases mav have to remain in the hospital for three or four weeks and thereafter spend several weeks in a convalescent camp.

Great care should be taken to protect the convalescent from secondary infections. Wherever it is possible beds should be isolated one from another by sheets, as in acute respiratory infections, for secondary bronchitis and bronchopneumonia are not uncommon and the danger of cross infection should be provided against.



The symptoms, here, are usually delayed from 3 to 24 hours, and dangerous symptoms do not, as a rule, appear for from 24 to 48 hours after exposure, but pulmonary edema and symptoms similar to those observed in the suffocative cases may occur; moreover, the patient may have had a double exposure to different sorts of gas. All the precautions, therefore, above mentioned should be observed at the outset, but other special steps must be taken.


Wherever exposure to a vesicant gas is suspected, the use of external warmth should be avbided if the clothes have not previously been removed. The application of heat favors the diffusion of the gas.

Remove the clothes as soon as possible but protect the patient from exposure during the process

After removal, the clothes should be sterilized in wet steam for 30 minutes; in dry heat for 15 minutes; exposed to the air for 15 minutes. This may be carried out in the Thresh sterilizer, and may have to be repeated twice, although two or even one treatment may be efficacious. While waiting for sterilization, have the clothes placed outside the quarters, in the open. All who handle the clothes must be protected by respirators and special oiled clothing and gloves.


The patient should be throughly bathed in a warm room in soap and water at the earliest possible moment. Areas which have been specially exposed may first be covered for a few minutes by a paste of 25 to 50 percent chloride of lime in water and then washed with warm water. Bathing with 0.05 percent permanganate of potassium is said to be useful.


When the skin is dry, erythematous areas may be powdered with subnitrate or subcarbonate of bismuth, oxide of zinc, talcum, or any simple nonirritating powder. Moist and raw surfaces may also be powdered with the same substances, or a powder consisting of oxide of zinc, carbonate of magnesia, carbonate of lime, 200 grams; talcum powder, 400 grams, and protected from the bedclothes by cribs, or covered by a nonabsorbent dressing.

If a moist dressing be preferred a solution consisting of sodium chloride, 70 grams; sodium bicarbonate, 150 grams; water, 5,000 grams, may be used---simply limewater.

Blisters should be carefully attended to. The contents of the vesicles are poisonous and irritating to the surrounding skin; the blisters should, therefore, be opened carefully and the contents taken tip with absorbent cotton, which should promptly be burned. Interdigital areas should be washed carefully daily, powdered, and bandaged.

Fatty salves, in the early stages, are inadvisable, as any underdestroyed poison which remains on the skin mnay be diffused underneath.

Later, deep and painful burns are much relieved by treatment with ambrine.

The eyes should be irrigated immediately with warm alkaline solutions such as the above-mentioned solution of sodium chloride, sodium bicarbonate, and water. After this some nonirritating oil such as liquid albolene should be instilled. The patient should be kept in a dark room or the eyes shaded. Compresses soaked in this solution may give comfort in the acute stage. In severe cases, frequent (every two to three hours) irrigation of the conjunctiva with simple boric solutions (sodii boratis, 65; aquac camphorae, 30) followed by the instillation of liquid albolene should be carried out.

The nose should be sprayed with a warm alkaline solution (sodium chloride, sodium bicarbonate and water, as above) and also with liquid albolene, to which a little menthol may be added (such as the preparation known as "chloretone inhalantt").

The mouth should be rinsed with alkaline washes and gargles.

The laryngeal inflammations may be relieved by inhalation of menthol, 0.65; tinct. benzoini comp). ad 30, of which 5 c.c. are added to 500 c.c. steaming water.



"Mustard" cases may develop grave secondary bronchitis, with bronchopneumonia. In the treatment of such instances there is nothing specific. Every precaution should, how ever, be taken to prevent cross infection. The beds of all patients with purulent bronchitis and bronchopneumonia should be screened one from another and from their neighbors.


In soldiers who have been "gassed," especially with phosgene, symptoms similar to those characterizing D. A. H. (effort syndrome) are not uncommon---dyspnea on exertion--pain in the chest, palpitation, dizziness, fatigue on exertion, disturbed sleep with dreams, paroxysms of coughing, and even asthmalike attacks. These patients are often polycythemic. Nervous manifestations unassociated with apparent organic lesion are common.

Get these patients out of bed and start carefully graduated exercises, sending them as soon as possible to a special training camp.

"Functional" photophobia and blepharospasm are frequent, but eye shades and colored glasses should be discontinued as soon as the acute inflammatory stage is over. When this has passed the use of eyedrops of a solution of:

Zinci sulphatis..........................................................0.065-0.13 (gr. I-II)
Acidi borici ...............................................................3.75 (3T)
Aquae ......................................................................30 (3T)

is said to give relief. If corneal ulcers or iritis which are not common be present, they must be treated in the usual manner. Threatening though the ocular manifastations may be, recovery is usually complete. Grave damage to the uveal tract is rare. It is important not to overtreat the eves.

In all cases preserve an optimistic attitude; the great majority of gassed patients recover completely.

Do not let the patients become introspective or "hospitalized." Keep them occupied in mind and body. Get the "mustard" gas cases who have no respiratory involvement out of bed in two or three days if possible. Remove the eye shades as soon as the acute inflammatory stage is over. Send the men out of doors, look out for their employment or amusement, and get them under army discipline as soon as may be. Far too many convalescent gassed" cases tend to accumulate, uncared for, in base hospitals. The responsibility of the medical officer does not end with the disappearance of the dangerous symptoms. See to it that the patient does not become a psychoneurotic.

Attention to these details may save a considerable wastage of men.

Brigadier General, Chief Surgeon.