History

Chapter 18

Anesthesia for Combat Casualties on the Basis of Experience in Korea

Robert D. Dripps, M. D.

The following observations are based on a 6-week tour of Mobile Army Surgical Hospitals in Korea in the fall of 1952. During this visit as Consultant in Anesthesiology there was opportunity to administer anesthesia of a variety of types to battle casualties personally and to observe the response of the wounded soldier to anesthesia given by personnel with varied ability. Data on the problems of anesthesia for combat casualties are included under "Tools for Resuscitation" since surgery represents a fundamental part of resuscitation and anesthesia is essential for surgery.

Experience gained in Korea did not provide much new data on the anesthetic management of the wounded. Rather it is my opinion that the basic problems involved were merely re-emphasized, and one had the disturbing impression that mankind must relearn hard-won lessons, from individual experience rather than build on knowledge previously gained. A few quotations from the British Medical Research Council`s Special Report No. 26 entitled "Traumatic Toxemia as a Factor in Shock" (March 14, 1919) supports this belief. "The surgeon experienced another disappointment. If his measures were sufficient to put the soldier into a state that justified operation, this procedure produced a relapse. A great deal of the bad effects were to be attributed to the anesthetic. Chloroform had long been recognized as dangerous, but it was more evident that ether and other anesthetics were far from harmless. Gas and oxygen was the least noxious and with its wider adoption postoperative shock greatly diminished."

The severely wounded soldier is inordinately susceptible to narcosis regardless of the agent or technic selected. Prior to anesthesia he presents a picture of apathy and depression suggestive of decreased central nervous system function. He appears to be partially narcotized already. In such a patient small amounts of central nervous depressant drugs evoke a response out of proportion to the size of the dose administered. "Normal" dosage regimens will cause death sufficiently frequently to drive this point home to the tyro. The prolonged postoperative sleep of many of these patients tends to support the above. The physiologic basis for this susceptibility is not completely understood. It is undoubtedly bound up with the numerous

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factors responsible for shock and hence has humoral, endocrine, toxic, hemodynamic and psychic aspects, to mention a few.

Experiences in World War I also emphasized the hazard of moving the combat casualty, the necessity for parenteral fluids, the problem of the optimal time after resuscitation for surgical intervention and the question of how much to do at a particular time. These are the crucial questions which World War II revived and which were again noted in Korea. Unless atomic or hydrogen bombs bring physiologic changes peculiar to them, one can expect future conflicts to pose the same problems.

From the standpoint of "choice of anesthesia" one can set down the following generalities.

Preoperative Medication

The use of morphine to relieve pain, to prepare an individual psychologically for operation and to reduce the amount of additional drugs needed for anesthesia has been traditional. Yet many investigators have recorded the untoward reactions of man to morphine. Its ability to impair the normal compensatory response to circulatory stress is well documented. The prolonged action of a single dose can be shown readily. Such side actions as nausea, vomiting, urinary retention and constriction of smooth muscle in the biliary and respiratory passages are undesirable. Because of tradition, however, it has been difficult to eliminate the injection of morphine. Yet morphine has little or no place in the management of the seriously wounded. Men in shock rarely complain of pain. They do complain bitterly of thirst but this is not an indication for morphine. They may be anxious and fearful. These are not indications for morphine. Beecher has suggested barbiturates. I wonder if any depressant drug is needed. The sympathetic attention of corpsmen, doctors and nurses does wonders. If, as anesthesia progresses and resuscitation becomes effective, large amounts of anesthetic drugs appear necessary, the intravenous injection of morphine, or meperidine (demerol) may be useful.

The educational campaign outlining the possibilities of harm of morphine must be continued, for although abuse of this drug is now less frequent, over dosage is still seen. Aidmen and medical officers must be made to understand the drug better. In the event of overdosage, n-allylnormorphine appears useful in reversing both the respiratory and circulatory depressant effects. This drug, which is administered intravenously, will return respiratory minute volume towards normal within 60 seconds. Its pressor effect is not as well substantiated at the moment but a blood pressure raising action has been described.

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The belladonna drugs are still used and may be given intravenously as well as intramuscularly. Whether scopolamine is preferable to atropine cannot be stated with finality. The tendency of the former to produce mental aberrations is undesirable.

Choice of Anesthesia

The guiding principle for the administration of anesthesia to any patient is use of the least amount of narcotic compatible with the surgical requirements. As already stated, this is essential in the severely wounded. The susceptibility of the serious battle casualty to anesthesia enables one to provide satisfactory working conditions with 50 to 60 per cent nitrous oxide in oxygen in many patients. This concentration will not produce even minimal surgical anesthesia in normal individuals, but if satisfactory results can be obtained the shocked patient has been spared the consequences of a more potent depressant. This technic deserves continued application. I used it successfully in Korea, as did others to whom it has been suggested.

It is difficult to divorce the problem of selection of anesthetic agent from a consideration of the background of the anesthetist. Fortunately the training of physicians in the specialty of anesthesiology has increased greatly during the past decade. Specialists were available at the forward surgical hospitals in Korea and in installations behind these mobile hospitals. Some of these individuals were trained in one approach to the anesthetic management of the sub-standard patients. Others had had a different indoctrination. Since convincing proof that one agent or technic was superior to another in the management of the severely wounded was not available, it seemed wise to permit anesthetists to apply those methods with which they were most familiar. If the patient`s susceptibility is kept foremost in one`s thinking, this approach appears reasonable. Experience in Korea justified this approach.

Those men trained primarily in the administration of thiopental soon realized that very small doses of this drug sufficed. Profound depression of blood pressure and respiration may be produced by 25 to 50 mg. intravenously. When such was the case, it was my opinion that thiopental should be abandoned since nitrous oxide with adequate quantities of oxygen then proved sufficient. If more thiopental were required but the amounts still did not compare to those used in patients in good physical condition, this fact was constantly kept in mind lest overdosage occur. Supplementation of the thiopental with nitrous oxide-oxygen was almost invariable.

It has been stated that the induction of anesthesia with ether alone is the preferable approach to the seriously wounded. Yet I have

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produced severe hypotension in battle casualties with this drug in apparently very light planes of anesthesia. According to recent studies the safety of ether so far as the circulation is concerned lies in its ability to mobilize epinephrine and norepinephrine from adrenal medulla and sympathetic nerve endings. If this be prevented totally or in part ether is a potent circulatory depressant. Probably in certain seriously wounded patients such mobilization is reduced.

Observations by Zweifach and Chambers of the greater tolerance of dogs to blood loss during cyclopropane as compared to ether is corroborated by Crooke`s statement during World War II that "the best anesthetic used in our shocked patients was cyclopropane," and the data of Hershey and Rovenstine on the value of cyclopropane in the management of patients with recent severe hemorrhage. I believe that this drug has a place in the anesthetic management of the battle casualty and that it does not deserve the neglect of military planners.

Unless it can be shown that some such technic as the use of a continuous drip of norepinephrine will maintain adequate circulation during spinal anesthesia, this method of pain relief probably has no place in the management of the seriously wounded. The circulatory alterations produced by spinal anesthesia would seem contraindicated for such patients.

For intra-abdominal operations in substandard patients, bilateral intercostal block can provide excellent muscular relaxation in light planes of general anesthesia. The block can be performed after the patient is put to sleep so that the multiple needle sticks are not objectionable. Other forms of regional anesthesia also have a place if dilute solutions are used and overdosage with its threat of hypotension is avoided. An 0.5 per cent solution of procaine is adequate for infiltration anesthesia. For nerve block, a 1 percent solution should suffice.

The "curare" group of drugs proved of great value in Korea. d-Tubocurarine and succinylcholine were most frequently used. These substances permitted rapid intubation of the trachea and provided muscular relaxation for varying periods of time as needed. Patients in shock tended to react to succinylcholine with an exaggerated degree of muscular fasciculation. Occasionally this motor activity resembled clonic convulsions. It is possible that this represented a diminished amount of plasma cholinesterase. This deserves study as one of the derangements associated with shock.

Illustrations of some of the principles discussed above are presented in Figures 1 to 10, which are copies of anesthesia records made in Korea.

Although the surgeon assumes the major responsibility, a competent anesthetist should always be part of the team charged with resuscita-

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FIGURE1. A 21-year-old American soldier with both legs blown off by amine. On the left side the loss was close to the pelvis; on the right the loss occurred at the junction of the upper and middle third of the femur. Despite heroic transfusion therapy consisting of 14,000 ml. of whole blood in a period of 2 hours and with a pre-anesthetic blood pressure of 110/70 and a pulse rate of 111, attempts at anesthesia with nitrous oxide-oxygen (60:40) and attempts to prepare the wounds for d?bridement were followed by complete collapse of the circulation. Operation was therefore canceled.

tion of the wounded. From the standpoint of anesthesia the following aspects of resuscitation deserve continued study and evaluation.

1. Use of sympathetic ganglionic blocking agents or vasodilator drugs prior to the development of shock or during its treatment has been advocated by some. One of the theories behind such a suggestion is that the blood vessels can constrict excessively as part of compensation for hypotension. This concept was not tested in Korea.

2. The role of pressure drugs in the treatment of shock is still debated. It must be remembered that almost all of the pressure drugs except pitressin have the ability not only to constrict blood

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FIGURE 2. The soldier discussed in Figure 1 was re-anesthetized 48 hours after the first attempt. By this time he had received a total of 19,000 ml. of whole blood, had a blood pressure of 124/70 and a pulse rate of 126. High bilateral amputation of both thighs was successfully completed under extremely light anesthesia with small amounts of thiopental and nitrous oxide-oxygen.

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FIGURE3. A 23-year-old white male who was pale, "tired" and thirsty despite 2,500 ml. of whole blood. His right leg had been blown off below the knee by a mine. Blood pressure was 144/90 and pulse rate 154. The relatively high blood pressure suggested maximal efforts at compensatory vasoconstriction, and warned of hypotension with induction of anesthesia. This occurred as thiopental (200 mg.) was administered slowly over a 10-minute period. A more seriously ill casualty might have had an even greater decrease in blood pressure. Note the reduction in pulse pressure following anesthesia with thiopental.

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FIGURE 4. A 24-year-old white male with multiple penetrating wounds of the abdomen. The pre-anesthetic pulse rate of 148 and the high diastolic pressure should have warned of circulatory instability. Induction of anesthesia with thiopental was followed by a sharp decrease in blood pressure and a narrowing of the pulse pressure. The addition of ethyl ether vapor at 4:00 p. m. brought a further reduction in arterial pressure. Five thousand ml. of fluid was administered during the operation. A pressor drug-neosynephrine-appeared of value.

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FIGURE 5. A 26-year-old white male with penetrating wounds of the right side of chest, right hand, and arm and left thigh. This soldier did not appear to be seriously wounded. The hypotension which followed the onset of anesthesia was related to a gross overdosage of thiopental. A technician anesthetist administered 1.5 gm. of this drug in 15 minutes in an effort to facilitate tracheal intubation. One cannot blame the drug in this instance so much as the way in which it was administered. It was fortunate that a fatality was averted. Had such a patient died, autopsy would have disclosed nothing and the casual recorder might have misunderstood the cause of death.

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FIGURE 6. A 24-year-old white male who was not in shock prior to anesthesia. After 2 hours of a satisfactory thiopental-nitrous oxide-oxygen anesthesia this patient began to hiccup. The anesthetist failed to realize that thiopental accumulates in the body as anesthesia progresses. Its rate of destruction (about 15 per cent per hour) is slower than many recognize. Injection of 125 mg. of thiopental, a dose which was well tolerated at 6:00 p. m., caused profound respiratory and circulatory depression at 7:50 p. m. Again death could have resulted had a larger dose been injected.

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FIGURE 7. A 24-year-old white male with gas gangrene in a right thigh amputation stump. Inadequate fluid therapy was partially responsible for the severe hypotension noted. Ether anesthesia, however, although only mid-first plane according to clinical signs, appeared to contribute to the profound circulatory collapse.

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FIGURE 8. A 23-year-old white male who did well during secondary closure of 35 penetrating wounds of the head and extremities. Operation, which required almost 3 hours, was performed under dilute procaine 0.5 per cent. The total volume of solution was high, but it must be remembered that this amount was given over a long period of time, hence toxicity of the local anesthetic proved unimportant. The value of a dilute solution of a local anesthetic in avoiding toxicity cannot be overemphasized.

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FIGURE 9. A 23-year-old white male with a large gaping wound of the face and multiple penetrating wounds of the thigh. On admission this individual was pale, thirsty, with a blood pressure of 90/70. After what appeared to be successful resuscitation with parenteral fluids, the patient was moved about 60 feet for x-ray examinations. Blood pressure promptly decreased from 130/86 to 80/60. This adverse effect of motion on the blood pressure was commonly seen. After additional efforts at resuscitation, induction of anesthesia was also followed by a decline of blood pressure from 112/72 to 60/45.

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FIGURE 10. A critically injured 29-year-old Negro with penetrating wounds of the abdomen, skull and lower extremities. Onset of anesthesia was followed by profound hypotension. Neosynephrine was of no value, but norepinephrine by constant intravenous infusion restored blood pressure to normal limits. Each time that the drip of this drug was slowed hypotension occurred.

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vessels, but also to increase myocardial contractions. Thus, there are two problems to be evaluated: (1) Is there virtue in decreasing the vascular capacity via vasoconstriction-venous as well as arterial; (2) Is there utility in stimulating the heart? It was my clinical impression that pressor drugs were of value in occasional patients in Korea. Not infrequently less potent agents such as phenylephrine (neosynephrine) and methoxamine (vasoxyl) were inferior to norepinephrine (levophed), but there did seem to be a place for these substances in the management of hypotension and shock. Convincing data were not obtained, however.

3. The administration of hydrocortisone, preferably intravenously, has appeared to some civilian observers to restore vascular reactivity to pressor drugs or to the naturally occurring substances, epinephrine and norepinephrine. This concept deserves continued exploration. Korea did not add to my knowledge of this possibility.

4. The role of oxygen in the treatment of shock also remains unclear. Oxygen via nasal catheter was used in Korea as part of the resuscitation program in some casualties. Again only clinical impressions are available and these are contradictory.

5. The desirability of warming the cold battle casualty has been debated. It appeared to me that shivering, pilomotor phenomena and peripheral cyanosis from cold were unnecessary stresses for a patient but proof is lacking.

6. The adverse effect of motion on a partially resuscitated patient was demonstrated frequently. The hemodynamic alterations responsible for this remain to be demonstrated, although pooling of blood somewhere seems the best explanation.

7. The development of hypotension with the onset of general anesthesia was frequent. Presumably this represents dilation, primarily of skeletal muscle blood vessels, but this should be studied.

8. The utility of the intra-arterial route for administration of blood has been challenged convincingly in the experimental animal. Whether certain clinical impressions of the value of this resuscitation measure will ever be substantiated is uncertain at the moment. Most will agree, however, that the hazards of the method are not inconsiderable.

9. A better method for administering blood intravenously under pressure is needed. Air embolus occurred in Korea and is an unnecessary hazard of blood transfusion.

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