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ACCESS TO CARE
Ernest A. Doud, M.D.
The excellent anesthesia provided for casualties with wounds of the chest in World War II was brought about by two developments between the two World Wars. The first was the development of intratracheal positive pressure absorption anesthesia. The second was improvement in the knowledge of cardiorespiratory physiology (1).
Thoracic surgeons and anesthesiologists with adequate equipment were dispersed from the forward areas of the combat zone back through the chain of evacuation. This policy greatly reduced the fatalities from chest wounds as well as their morbidity. It permitted the prompt and competent care of nontransportable casualties by providing for surgery, when it was necessary, as near the frontline as it was practical to provide hospital facilities.
The need for qualified anesthesiologists for the management of thoracic injuries was recognized early in the war. It was also recognized that they must take the responsibility for more than the administration of anesthesia. In addition to relieving the surgeon of all concern for anesthesia, they assumed the responsibility for shock therapy during operation, and, when it was practical, before operation. They also coped with the ever-present problems of pulmonary secretions and accumulations of intratracheal blood by repeated catheter aspiration during operation, and, if necessary, by bronchoscopy immediately afterward.
The duties of the anesthesiologist and his relation to the surgeon are excellently stated in the final report of the 2d Auxiliary Surgical Group on forward surgery:
* * * the anesthetist carries a large part of the responsibility in treating severely wounded men. The more competent the anesthetist the less the burden on the surgeon. With a well-qualified anesthetist at the head of the table the surgeon can give his undivided attention to the operative procedure itself.
It was generally agreed that such an anesthetist could "support an inexperienced surgeon better than a brilliant surgeon [could] maintain an inexpert anesthetist."
Satisfactory anesthesia depended upon adequate equipment. There were many deficiencies early in the war, both in North Africa and in Sicily. Even in the Sicilian campaign, some thoracic surgical teams of the 2d Auxiliary Surgical Group did not have anesthesia machines. Inductions had to be carried out with open drop ether or ethyl chloride, or with Pentothal sodium (thiopental sodium), with oxygen administered by face mask or nasopharyngeal catheter. In many instances, the entire intrathoracic procedure was carried out with intravenous Pentothal sodium (p. 84).
FIGURE 33.-Improvised anesthesia apparatus used in Sicily by the 2d Auxiliary Surgical Group. The oxygen cylinder (a), oxygen flow regulator (b), and humidifier (c) were standard hospital equipment. Other items improvised included the connection tubing (d), ether vaporizer (e), breathing bag (f), soda-lime canister (g), and face mask (h).
There were numerous improvisations (fig. 33) in many of which ordnance and engineering units assisted. Several types of ether vaporizers were devised. Positive pressure was obtained by occluding the escape valves of masks through which oxygen was administered and manually compressing the attached small breathing bag. Neither nitrous oxide nor soda lime was available at this time. Large volumes of oxygen were used to dilute the carbon dioxide.
After November 1943, these difficulties no longer existed. Several types of excellent anesthesia machines were distributed, and there were ample supplies of oxygen, nitrous oxide, ether, Pentothal sodium, and soda lime. The equipment and supplies were made available not only to hospitals but to the mobile surgical teams. Thereafter, anesthesia left nothing to be desired, for by this time the anesthesiologists had learned the necessary lessons of wartime anesthesia by their experiences in the early campaigns.
The excellent results obtained in all types of combat injuries in World War II could be attributed in large part to the excellent preparation of the
casualties for both anesthesia and surgery. Originally, until thoracic surgical teams were assigned to field hospitals, surgeons were responsible for triage; resuscitation and preoperative preparation, including procuring blood for transfusion from neighboring service troops; and determination of the optimum time for operation. When field hospitals were set up adjacent to clearing stations, which was first done in the campaign in Sicily, thoracic surgical teams were assigned to them, and anesthesiologists took over the major part of the responsibility for resuscitation. They employed, as necessary, replacement therapy, nasotracheal catheter suction, tracheal intubation, paravertebral block, and whatever measures might be necessary (p. 241). They also assisted the surgeon in determining the optimum time for operation. This was preferably after resuscitation was completed. If, however, the condition of the casualty continued to deteriorate in spite of adequate therapy, whatever surgery was indicated was performed at once.
Preoperative medication-Preoperative medication was almost always administered intravenously in the operating tent, to make certain of satisfactory absorption, so that whatever drug was used would have the optimum effects at the desired time.
All patients, except those in deep shock, were given atropine sulfate (gr. 1/150 to 1/100). If sedation was thought necessary, morphine tartrate was administered (gr. 1/8 to 1/4). It was always administered cautiously, for it was not infrequently found that casualties with chest wounds had already received too much. Until this was realized, acute morphine intoxication was not uncommon. When the circulation improved in response to resuscitative measures, the morphine previously administered to casualties in shock, who had been exposed to cold and wet weather, was rapidly absorbed. In such circumstances, an additional dose of morphine could be dangerous (p. 244).
For this reason, intercostal or paravertebral nerve blocks with procaine hydrochloride (Novocain) were frequently used in preoperative preparation in preference to morphine. If the injuries involved only the chest wall, patients who had been treated by nerve block during resuscitation could sometimes be operated on with the addition of procaine infiltration analgesia. This method, however, had a limited use, because the multiplicity of wounds restricted the employment of both local and regional anesthesia.
Induction-Anesthesia was easily induced in some patients with ether and oxygen or with open drop ether. In other cases, nitrous oxygen and oxygen were used, with the gradual addition of ether. When it was advisable to eliminate possible excitement during induction, the most satisfactory combination of drugs was the intravenous use of Pentothal sodium (table 13) in 2.5- to 5-percent solution and the topical use of cocaine in 4- to 10-percent solution, with preliminary oxygenation.
1Endotracheal anesthesia was used 3,042 times in evacuation hospitals and 1,782 times in field hospitals, this being 31.2 percent and 83.0 percent, respectively, of the inhalation anesthetics given in those installations.
Anesthetic agents-Ether was the principal anesthetic agent used in most chest wounds. It was seldom used alone but was highly satisfactory when combined with nitrous oxide and oxygen, or with Pentothal sodium, or simply with oxygen.
Pentothal sodium with oxygen was used as the principal anesthetic agent only when lack of equipment and supplies required it, which was seldom the situation after the campaign in Sicily.
This agent had many advantages: It did not irritate the bronchial mucosa. Respiratory movements were reduced to a minimum, and the surgeon therefore did not suffer from interference by them. Controlled respiration was easily effected with it. When it was used with ether, only small amounts of that agent were required. On the other hand, Pentothal sodium gave rise to occasional laryngospasm, and the postoperative respiratory depression that it caused was likely to be prolonged. The chief reason for restricting its use to selected patients and for using it only when other types of anesthesia were not possible was its very small margin of safety. It was not a proper agent for general use.
Positioning-Unless there were contraindications, such as head injuries, the modified Trendelenburg position was used during operation, for two reasons. The first was that it reduced the possibility of air embolism. The second was that it was helpful in improving the condition of the casualty, particularly the shocked casualty, during anesthesia.
Tracheal intubation-The trachea was intubated routinely, to facilitate positive pressure for pulmonary control and expansion without causing gastric dilatation. Another purpose was to stabilize the mediastinum during intrathoracic surgery. A soft rubber catheter was passed through the tube, and frequent tracheobronchial aspirations were carried out to protect the contralateral lung from gravitated material.
The tube used was the largest which would pass through the glottis without difficulty. Some anesthesiologists preferred a tube with an inflatable cuff, in the belief that the cuff prevented fluid accumulations in the trachea from escaping around the tube into the pharynx. Others preferred to pack the pharynx with moistened gauze, in the belief that the packing prevented the tube from acting as a wick to permit regurgitated material to be drawn into the trachea. Still others preferred to place a mask over the tracheal tube, thus producing a seal for attaining positive pressure.
Usually when the ether was used, and always when Pentothal sodium was used, the respiratory exchange was increased by rhythmic manual compression of the breathing bag throughout the operation.
Opinion was divided as to whether intermittent positive pressure anesthesia or the apneic technique of controlled respiration was the preferred method for maintaining anesthesia for surgery with open pneumothorax. However it was attained, 2-3 mm. Hg pressure prevented mediastinal shift, and 10-12 mm. Hg pressure was used to expand the lung for short periods every 20-30 minutes during operation, as well as when the wound was being closed.
Curare-Curare was used intravenously by one surgical team during the Italian campaign to obtain abdominal relaxation and to facilitate tracheal intubation (2). The drug, which was not on the approved list, was supplied to the anesthesiologist of this team by the manufacturer and used by special permission on a trial basis. Curare proved extremely useful in obtaining abdominal relaxation, but it never came into widespread use, one reason being that the supply was scanty.
ADJUNCT THERAPY DURING OPERATION
As accurate as possible an estimate of the blood lost was made as the operation progressed, and the estimated loss was replaced as it occurred, to prevent the casualties, whose balance was always delicate, from slipping into shock. The physical status of many patients improved during operation because of (1) the increased efficiency of respiratory exchange following aspiration of the trachea and administration of oxygen in high concentration, (2) the effects of the Trendelenburg position, and (3) intravenous replacement therapy, usually in the form of whole blood transfusions.
The anesthesiologist was kept fully employed during operation with the administration of the anesthetic; maintaining respirations; keeping the tracheobronchial tree free of fluid; constant evaluation of the patient's condition; and the administration of intravenous fluids, sometimes under pressure, to increase the rate of flow if the blood loss was particularly heavy.
Bronchoscopy was not routinely used at the end of thoracic operations, chiefly because most anesthesiologists believed that increasing the depth of anesthesia at this time would have deleterious effects. It was, however, used
whenever necessary to make certain that respiratory passages were clear of blood and mucus, as well as to determine the patency of the bronchi if too great resistance was offered to pulmonary expansion. It always had to be borne in mind that the uninjured lung had been in a dependent position during surgery. It was frequently necessary to clear the left stem bronchus, which was likely to present special difficulties.
Bronchoscopy was sometimes necessary, before operation, to clear accumulations in the tracheobronchial tree after failure of attempts at blind nasotracheal suction. Circumstances sometimes made it wiser to delay suction until the tracheal tube was inserted after rapid induction of anesthesia. Oxygen was administered with a little positive pressure after each brief period of suctioning. When the respiratory passages had been satisfactorily cleared, anesthesia was continued and the operation proceeded with.
The chief risk of bronchoscopy, the vagovagal reflex, could be eliminated by the administration of atropine before the procedure was undertaken. The risk of omitting it is evident in the following case history:
Case 1-This casualty, a 23-year-old soldier, was injured by a high explosive shell fragment on 26 May 1944 at 0730 hours. He was admitted to a field hospital 4 hours after injury, after having received morphine gr. ½ and 3 units of plasma. The blood pressure was 84/50 mm. Hg and the pulse 120.
The wound of entry was over the eleventh rib, in the left posterior axillary line, and was 4 cm. in diameter. The wound of exit was in the anterior axillary line and was 6 cm. in diameter. Omentum had herniated through both wounds. The left chest was silent, and haziness was evident throughout it by roentgenologic examination. The abdomen was tender and rigid.
The patient received another unit of plasma and 1,400 cc. of blood before operation. Preoperative medication consisted of morphine gr. 1/8 and scopolamine gr. 1/100. When operation was begun, the blood pressure was 110/70 mm. Hg and the pulse 110.
Operation was begun at 1430 hours. The wounds of entry and exit were debrided, and a large hematoma of the muscles was excised. Segments of the eighth, ninth, and tenth ribs were found shattered; their rough edges were smoothed.
An intercostal incision was then made through the eighth interspace. The pleural cavity contained 1,000 cc. of blood. Part of the stomach, the transverse colon, and the spleen, covered by omentum, had herniated into the left chest through a huge rent in the anterolateral portion of the diaphragm at its point of attachment to the chest wall. The spleen was widely macerated, but the pedicle had not been injured, so bleeding was not profuse. Splenectomy was performed and the damaged omentum resected. The tail of the pancreas was found lacerated and was repaired with interrupted cotton sutures. A 3-cm. laceration of the serosa over the greater curvature of the diaphragm was closed with some difficulty by two-layer imbricating cotton sutures. The phrenic nerve was paralyzed. The chest was irrigated with 2,000 cc. of physiologic salt solution. The wound was dusted with 5 gm. of sulfanilamide powder and closed in layers. Mobilization of muscles was necessary to secure adequate closure. A heavy dressing of gauze and wide adhesive was applied to stabilize the chest. Replacement therapy during the operation, which took 2 hours and 15 minutes, consisted of 500 cc. of blood.
The bronchoscope was then introduced, without difficulty. Although the patient had previously been in excellent condition, he became cyanotic and pulseless just as the procedure was being terminated. The immediate insertion of an intratracheal tube and the use of artificial respiration were without effect. The heart was not heard any time after bronchoscopy was performed.
An immediate post mortem examination showed the heart to be flabby and dilated, but otherwise, except for the traumatic damage, no abnormalities were found.
Comment-It was concluded that the patient died of a vagovagal reflex, which undoubtedly could have been prevented by atropinization before the bronchoscope was introduced.
1. Graham, E. A.: A Brief Account of the Development of Thoracic Surgery and Some of Its Consequences. Surg. Gynec. & Obst. 104: 241-250, February 1957.
2. Doud, E. A., and Shortz, G.: The Use of Curare for Abdominal Surgery in Seriously Injured Patients. Anesthesiology 7: 522-525, September 1946.