Battle Casualties in Korea: Studies of the Surgical Research Team Volume III
The Bacterial Flora of the Blood in the Korean Battle Casualty*
Lieutenant Colonel Robert B. Lindberg, MSC, USA
Theodore F. Wetzler, B. S.
Major Arthur Newton, MSC, USA
Captain John M. Howard, MC, USAR
Captain John H. Davis, MC, USAR
1st Lieutenant Joseph Strawitz, MC, USAR
with the technical assistance of Corporal John H. Wynn, AUS
The purpose of this study was to describe the bacterial flora of the blood stream of the severely injured casualty at the time of his arrival at the 46th Mobile Army Surgical Hospital. The primary intent was to describe the bacterial flora for guidance in therapy. A secondary purpose was to survey this problem in patients in deep shock in order to ascertain the possible secondary development of bacteremia due to permeation of the ischemic bowel. 1-3
The importance of this information lies in the fact that many casualties had large contaminated wounds of soft tissues; and others had perforations of the gastrointestinal tract. with peritoneal
contamination.
This study was carried out on the eastern front in Korea from January 1952 through June 1953. At this time, the tactical conditions were stable to such an extent that evacuation of casualties were optimal. Except when wounded on patrol, the casualty usually reached a battalion aid station within 1 hour after injury. At the aid station, antibiotics were often administered in addition to the vital resuscitative measures; however, such measures were less frequently employed by medical officers of the Korean Army. The treatment most frequently given was 600,000units of penicillin, intramuscularly. The severely injured casualty was evacuated immediately by helicopter or ambu-
*Previously published in Annals of Surgery 141: 366, 1955.
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lance. At the time of arrival at the forward surgical hospital, the casualty was taken immediately to the Resuscitation Ward. Blood cultures were obtained at this time on only the most severely wounded casualties.
This study includes only the severely wounded casualties as they were admitted to the forward hospital. The average time following injury was 3.5 hours.
Methods and Materials
After preparing the skin with iodine and alcohol, venous blood was drawn using aseptic technic. For aerobic culture, from 1 to 3 cc. of blood were added to 7 cc. of dextrose broth. For anaerobic culture, 5 cc. of blood were added to a 100-cc. bottle containing 50 cc. of trypticase soy-bean broth and carbon dioxide at a subatmospheric pressure (Becton-Dickinson Vacutainer Bottle). In the first study, penicillinase was added to all media at the time of inoculation. After an incubation period of 48 hours or longer, smears were examined and, at the same time, blood-agar plates and tubes of cooked meat broth were inoculated. The latter were incubated 72 hours, then subcultured for recovery of clostridial organisms. The original culture tubes were retained for a period of 1 or 2 months and checked for delayed growth.
A study of 170 patients was carried out at two separate laboratories. In the first group, 117 casualties were studied; and, of this number, 35 patients had received penicillin prior to culture. Of the group receiving penicillin, 8 patients had also received 1.0 gin. of streptomycin. In the second group, 52 patients were studied; and, of this number, 37 patients had received penicillin and four had also received streptomycin. The time lag was similar in the two studies.
In this study, patients were considered in shock if they presented signs of blood-volume deficiency in association with a systolic blood pressure below 100 mm. and a diastolic below 70 mm. If these signs were associated with a systolic blood pressure below 50 mm., the patient was considered to be in severe shock. Accordingly, in the first series, 59 patients were in shock on admission to the hospital, and 26 of these patients were in deep shock. Twenty-eight patients had visceral perforations. In the second group, 31 patients were in shock and 12 of this number were in deep shock. In the second series, 16 patients had visceral perforations. The two groups, therefore, consisted of casualties with comparable degrees of injury. Twenty normal soldiers served as controls. In addition, 20 contaminated cultures were sent from the forward surgical hospital to the base laboratory, where they were recultured to establish the feasibility of shipment.
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Results
Of the 20 contaminated controls, all contained viable bacteria after shipment. Of the 20 control blood-cultures from the normal soldiers, all were negative.
The results of the two studies of battle casualties were similar (Table 1). In the first study of 117 casualties, 12 cultures were positive (10 percent). The predominant organisms grown were Staphylococcus albus and the organisms of the Bacillus species which are among the chief organisms of the skin and the air respectively (Table2). It is entirely conceivable that several of these positive cultures were the result of contamination, as it was sometimes difficult to obtain blood from a patient who was in shock.
Table1. The Bacterial Flora of the Blood
Table2. Organisms Isolated from Blood Culture-Series 1
The results of the second series differed in that Streptococcal strains were cultured from four
casualties and clostridia were cul-
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Table3. Organisms Isolated from Blood Culture-Series 2
tured twice.* Coliform organisms were found only once. The incidence of positive cultures was 21 percent (Table 3).
The incidence of positive cultures could not be related to the time lag, degree of shock, visceral perforation, or previous administration of antibiotics.
Discussion
In the over-all study of 170 severely injured battle casualties, 23 positive blood cultures were found (13.5 percent). In spite of careful technic, several of these may have represented contamination from the skin or the air; hence the figure is maximal. It is believed that the actual incidence of positive cultures of the peripheral blood stream lies between 4 and 6 percent in the most severely injured battle casualties; and presumably the wound is the portal of entry. Vascular collapse did not appear to alter this incidence. The results of this study in no way invalidate the observations of other investigators regarding the role of bacteria in the late refractory shock of animals. 1-3 However, of the 30 patients studied who died
*Prior to our study, this observation of a clostridial bacteremia was noted repeatedly in cases which were unreported and in a patient with peritonitis. No obvious break in technic was noted, but contamination can never be completely excluded.
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as a result of wounds, only three had positive cultures. Moreover, the 38 patients were in severe shock for an average of 7.3 hours (ranging from 1 to 36 hours). Cultures were positive for only three. One of these had been in shock 2 hours, and the other two for 4 hours.
Summary
A study of the bacterial flora of the blood stream in the severely injured battle casualty was carried out by two laboratories, one in Korea and the other in Japan. Blood cultures were studied on 170 severely injured casualties at the time of admission to a forward hospital. The incidence of positive cultures was 13.5 percent. Correction for possible contamination might lower this incidence as much as 4 or 6 percent.
The degree of shock, the type of injury, the time-lag, and the previous antibiotic therapy did not affect the incidence of positive cultures.
References
1. Fine, J., and Frank, H. A.: Progress Report, September 15, 1952. Subcommittee on Shock, National Research Council, Washington, D. C.
2. Fine, J.; Frank, H. A.; Schweinburg, F. B.; Jacob, S.; and Gordon, T.: The Bacterial Factor in Traumatic Shock. Ann. N. Y. Acad. Sci. 55: 429, 1952.
3. Hardy, E. G.; Morris, G. C., Jr.; Yow, E. M.; Haynes, B. W., Jr.; and De Bakey, M. E.: Studies on the Role of Bacteria in Irreversible Hemorrhagic Shock in Dogs. Ann. Surg.139: 282, 1954.
