Battle Casualties and Medical Statistics

SURGERY AND THE WOUNDED

Information on surgical operations is fundamental knowledge for a variety of medicologistical problems. It points up the need for surgical specialists and for ancillary personnel. It indicates the need for plasma and whole blood and for preoperative and postoperative care. It forms the basis for staffing, supply, and for supporting requirements for committing surgical and evacuation hospitals as well. And those most in need of surgery establish the priority for swift evacuation of the wounded from the battlefield, since, in wartime, emergency surgery cannot be postponed with the same degree of freedom that might be applied to other medical support considerations, such as alternate methods of treatment or optional means of evacuation and hospitalization.

In Korea in 1950, hospital support was austere and adequate surgical care could not always be rendered in country, especially because of the shortage of highly qualified surgeons. Early evacuation of the wounded either before or after their surgery was necessary under the circumstances. Not until October 1951 were sufficient skilled surgeons available to enable the Eighth U.S. Army Surgeon to organize professional specialty teams (9). Despite these handicaps, U.S. Army patients received life-giving surgery in Korea and Japan along with other improved medical procedures to the extent that the case fatality rate for wounded achieved a new low of 2.5 percent compared to the 4.5 percent experienced in all of World War II.

When surgical operations are related to the number of wounded requiring surgery (table 75), and when surgery such as debridement of wounds is excluded, 59 percent (46,024) of the 77,788 admissions to medical treatment facilities required one or more surgical operation. There were 89,974 surgical operations performed, for an average of 1.2 operations per total wounded or an average of two surgical operations per wounded patient for whom an operation was performed. When the number of operations are considered by type of surgery performed, genitourinary surgery averaged 4.5 operations per wounded who received genitourinary surgery; oral surgery averaged three operations, and neurosurgery and gastrointestinal and abdominal surgery averaged slightly over two operations for these specialties. All other specified types of surgical operation averaged two operations or less. With regard to anatomical location of wound and surgical specialties associated with the various body regions, the thoracoabdominal region averaged 1.4 operations per total wounded with wounds of the thorax and abdomen, compared to one operation for each wounded of either the head, face or neck area, or of the upper or lower extremities combined. When the number of surgical operations are restricted to those who received the operations, the distribution is slightly different. Surgical specialties associated with wounded of the head, face and neck area for whom operations were performed, averaged 2.2 operations, those with thoracoabdominal wounds and operations were almost identical with an average 2.1 operations, and those with extremity wounds and surgical operations averaged 1.8 operations. Although plastic surgery was undoubtedly performed on such body regions as the head, face, neck, and the extremities, this specialty was not separately identified in this connotation, and only those surgical procedures classified as plastic surgery, "not elsewhere classified (n.e.c.)" were identified. Attesting to its magnitude, however, even this restricted classification shows an average of 1.7 operations per wounded for which plastic surgery "n.e.c." was recorded.

Table 76 shows the surgical specialties by type of operation performed separately for wounded division and non-division troops. Of the 46,024 wounded with one or more surgical operations, 43,803 (95.2 percent) were division troops and only 2,221 (4.8 percent) were non-division troops. This, of course, is added testimony to the constant, and immediate need for surgical hospital support of frontline divisions. Other than order of magnitude, there appear to be no marked differences between the distributions by type of specialty. However, there were slightly larger proportions of thoracic surgery,

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¹Not applicable or data not available.

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gastrointestinal and abdominal surgery, and orthopedic surgery among division troops, whereas non-division troops showed a slightly higher relative proportion of neurosurgery (brain and meninges) than did the division wounded. This latter situation may result from the chance of non-division seriously wounded receiving medical treatment in contrast to division seriously wounded surviving to reach medical care.

SURGERY AND NONBATTLE ADMISSIONS

Unfortunately, nonbattle admissions were not processed to the same degree of detail as were the battle admissions and, therefore, only the number of admissions in Korea with surgical operation recorded by type of operation is available. The number of procedures and the specialties required, identified by specific area or origin, as Japan-Korea, are not at hand. Another difficulty arose in processing the nonbattle admissions for total U.S. Amy, Korea, by type of unit. Some of the cases which would ordinarily fall into the non-division category (after all division cases were properly identified) were inadvertently omitted at the time of processing. The number involved was small, however, and amounted to about 1 percent of the total counts for nonbattle admissions in Korea during the period July 1950-Deceber 1953. Table 77 provides a comparison of the differences related to total U.S. Army, Korea, and to the non-division group to which they apply. Even when compared with the overall counts for non-division admissions in Korea, the excluded cases amount to about 2 percent of the total, a not too significant proportion for the introduction of bias.

Unlike the wounded where almost all of those requiring surgery originated in division units, the surgical requirements for nonbattle admissions were about even by type of unit (table 78). There were, however, slightly higher proportions of nonbattle injury admissions with surgery originating from divisions (57.5 percent,) and slightly, lower proportions of disease admissions with surgery from divisions (46.0 percent). The relative proportions were reversed for nonbattle admissions with, surgery from non-division units, being 42.5 percent of all nonbattle injury admissions with surgery in Korea and 54.0 percent of all disease admissions in Korea with surgery.

When the comparison is made within each type of unit rather than between units, the divisions showed 53.5 percent of their nonbattle admissions with surgery were due to disease and 46.5 percent were due to nonbattle injury. With the nonbattle admissions with surgery restricted to those originating in non-division units, 64.7 percent were due to disease and 35.3 percent were due to nonbattle injury. For total U.S. Army, Korea, the overall proportions with surgery were 59.0 percent, due to disease and 41.0 percent due to nonbattle injury.

Tables 79 slid 80 present information by type of unit, and type of surgical specialty for disease admissions with surgical operations and for nonbattle injury admissions with surgical operations, separately. Excluding the relatively higher proportions for oral surgery among division troops and relatively lower proportions for genitourinary surgery, there are no major differences between these two types of units for disease admissions with surgical operations. The two surgical specialties with the highest proportionate shares of disease operations were (1) gastrointestinal and abdominal, and (2) genitourinary surgery. Nonbattle injury, admissions with surgical operations show only very

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slight variations between division and non-division troops for oral surgery, thoracic surgery, genitourinary surgery, and plastic surgery. The highest proportions are concentrated in orthopedic surgery and general surgery of the extremities. In terms of nonbattle admissions, with operations per 1,000 average strength per year, disease admissions with an operation rate of 52 per 1,000 exceed those for nonbattle injury of 36 per 1,000 per year. For disease, the non-division troops are highest with a rate, of 58 per 1,000 per year compared to 46 per 1,000 for divisions. On the other hand, the nonbattle injury admissions with operations show the highest annual rate (40 per 1,000) among the

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division troops with non-divisions amounting to only 32 per 1,000.

MEDICAL SURVEYS OF REPATRIATED PRISONERS OF WAR

Two POW exchanges were arranged by the armistice negotiators in Korea, for which medical surveys were performed. The first exchange involved 149 U.S. military personnel in need of immediate medical treatment who were prisoners of the enemy: 127 Army, 19 Navy-Marine, and three Air Force personnel. This exchange took place over a 2-week period between 21, April and 3 May 1953 and was referred to as "Little Switch." The second exchange of prisoners occurred after the armistice agreement was signed and included 3,596 U.S. military personnel desiring repatriation: 3,195 Army, 184 Navy-Marine, and 217 Air Force personnel. This latter exchange of prisoners took place between 4 August and 6 September 1953 and was designated "Big Switch." Two U.S. Army personnel were included in Little Switch for whom medical records were not received and 11 names (10 Army and one Air Force) were listed in Big Switch, for which most of the medical records were not received. The available data, therefore, cover medical surveys of 147 individuals from Little Switch and, for the most part, 3,585 individuals from Big Switch. Where data are available, information is given for 3,596 individuals.

The ages of these former prisoners of the enemy at the time of physical examination are shown in table 81. The majority (93 percent) were between 20 and 34 years of age, an additional 157 were between 35 and 39 years, and 68 were 40-54 years of age. Forty-two were 19 years of age or less, and the age was not stated for the remaining five.

When the amount of weight lost is related to the nature of their body build at the time of capture (table 82), those with the heavier body build apparently lost more weight on the average. The prisoners exchanged during Operation Little Switch show greater average weight loss, reflecting their poorer physical condition. This is also true when weight loss is related to weeks of captivity with one exception: the 50-99 weeks' interval. No reason is apparent for this difference other than the chance

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variation resulting in part from the extremely small numbers of cases included in the first five intervals for Operation Little Switch.

Table 83 shows that almost all (145) of those included in Little Switch and slightly less than two-thirds (61.5 percent) of those included in Big Switch were identified as ever having been wounded. When the distribution by anatomical location of wound is compared with all nonfatal wounded for U.S. Army, Korea (table 45), and with wounded evacuees received in continental United States from Japan-Korea, (table 71.), there were slightly higher proportions of head wounds and chest, abdomen, and back wounds among the exchanged prisoners and a slightly lower proportion of extremity wounds. These ratios were 18.2 percent and 16.0 percent, for head, face and neck among the total wounded and the evacuee wounded, respectively, compared to 21.8 percent for head wounds among repatriated prisoners of war. The thoracoabdominal region showed 15.4 percent and 15.7 percent, respectively, for the two former distributions compared to 16.7 percent for the chest, abdomen, and back combined among the repatriated prisoners. Extremity wounds were 66.3 percent and 68.1 percent, respectively, for the first two distributions and only 61.5 percent for the repatriated prisoners of war who had been wounded.

There were 618 cases (17 percent) of those repatriated for whom survey medical records were received which recorded a surgical operation while, in captivity (table 84). Only 11 (2 percent) had a major amputation, although the majority of amputees were exchanged in Operation Little Switch where 11 percent with surgical operation involved a major amputation, of one or both extremities. Minor amputations of fingers or toes were involved in 9 percent of the surgical operations and 1.8 percent of the operations involved the removal of foreign bodies. The majority of cases with surgical operation in both POW exchanges involved "other types not stated."

The results of intensive physical examinations of the U.S. military repatriated prisoners of war are shown in tables 85-89. Four-fifths of all repatriated prisoners were in good mental health and morale, and only 18 percent suffered from psychiatric conditions upon examination (table, 85). The largest proportion (7 percent) were diagnosed as psychoneurotic, with character and behavior disorders second at 6 percent. Only 1 percent of all returned prisoners were classified as being psychotic.

Results of physical examinations of the eyes, lips, and mouth are presented in table 86. Almost 90 percent of all the repatriated prisoners showed no abnormalities involving these anatomical areas, although the proportion was less for those exchanged during Operation Little Switch. Of those with eye

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conditions noted, conjunctival changes showed the highest relative proportions. Gingivitis, bleeding, had the highest, proportional ratio for lip and mouth conditions, with no other diagnosis showing any appreciable amount in total. During Operation Little Switch, however, atrophy-papilla of tongue was the leading mouth condition diagnosed, amounting to one-third of the conditions found and representing a ratio of 8 percent of all the prisoners exchanged during Operation Little Switch.

Only 12 prisoners had malaria, all of whom were exchanged during Operation Big Switch. Six were diagnosed as falciparum, five as vivax, and one as malariae. The results of chest X-ray examinations (table 87) show more than 90 percent of the exchanged prisoners with no pathology. This proportion was smaller during Operation Little Switch, of course, because the very nature of the prisoners' condition qualified them for inclusion in the first exchange. In total, however, fewer than 2 percent of all prisoners had active tuberculosis and about equal proportions, or less, showed any other form of lung pathology.

Examination of the skin and body surface (table 88) showed 78 percent of all of the prisoners had no skin abnormality; in Operation Little Switch, however, only 48 percent were, free of any skin conditions. Of all prisoners with skin conditions, 56 percent had dermatophytosis, 8 percent had acne, and 6 percent had follicular hyperkeratosis. Of those with skin conditions who were exchanged during Operation Little Switch, 41 percent had follicular hyperkeratosis, 11 percent had dermatophytosis, and 10 percent had acne.

Stool cultures among prisoners exchanged during Little Switch showed shigella in seven cases and no pathogens in 127 cases; no reports were furnished for the remaining 13 who were exchanged. For Operation Big Switch, stool cultures produced shigella in 14 cases, salmonella in three cases, and no pathogens in 1,995 cases. No report was received for 1,120 cases, and 454 were stated as "other" unspecified. Table 89 presents the associated data on the results of stool examinations among repatriated prisoners of war. Two-fifths of all prisoners were found to harbor parasites. This figure was almost two-thirds for those exchanged during Operation Little Switch compared to 38 percent for Big Switch. The following various parasites were found: 59 percent ascaris, 8 percent amebae, and 7 percent hookworms. Twenty-five percent were not specified as to type. The only large proportional differences between the two prisoner exchanges were the higher ratios during Operation Little Switch for amebae (16 percent) and hookworms (11 percent) compared to 7 percent each for Opera-

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tion Big Switch, and the lower proportion for ascaris (43 percent) compared to 61 percent among prisoners exchanged in Operation Big Switch.

ESTIMATING BED REQUIREMENTS OVERSEAS

It is possible to estimate bed requirements on the basis of a series of probability values for patients remaining in hospital, by type of patient, or to estimate various types of disposition from hospital, as a function of time after the day of admission to hospital. These patient remaining and disposition distributions are commonly referred to as "curves" although, in the mathematical sense, they are but collections of discrete probabilities. Although the general properties of remaining and disposition curves, in this connotation, are well documented beginning with Love's study (13) on World War I casualties and later by Beebe and DeBakey (14) on World War II data, full potential of this knowledge was never applied to the complete interplay of requirements for fixed versus nonfixed facilities overseas. Beebe and DeBakey recognized the importance of considering the characteristics of the entire system and emphasized its benefits when applied to estimating bed requirements in forward or combat areas occupied by held armies. Their approach essentially involved the summation of the daily values comprising the remaining curve to determine the total accumulation of patients through a stated number of days (usually the number of the days in the theater evacuation policy) reduced by that proportion evacuated from the army area or theater. This adjustment was determined by assuming a fixed number of hospital days in the army area for evacuees and the length of time in days for the latter adjustment was necessarily arbitrary. Although Beebe and DeBakey recognized that patients are evacuated over time in keeping with various probability distributions, nevertheless, to further simplify computational procedures, they assumed all patients were hospitalized for the same number of days before evacuation; that is, if the last day hospitalized in

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the army area was 6 days, then no patient was evacuated before or after 6 days of hospitalization. This approach was similar to that used at the time by the Army Medical Department for estimating fixed bed requirements, the assumption being that a constant time to evacuation for all patients was valid for all evacuation policies. Thus, estimates for fixed beds were based on patient accumulations through the number of days in the stated evacuation policy, with no differences occurring in either overseas theater or CONUS (continental United States) patient accumulation between evacuation policies, until the length of days in a stated evacuation policy was reached. One result of this method was to develop an accumulation factor, or accumulation of patients remaining, after any number of days which was identical for the same number of days, regardless of the length of the theater evacuation policy. For example, the theater accumulation factor was the same at 5, 10, or 20 days for a 30-day evacuation policy as it was for a 60-, 90-, or 120-day evacuation policy. Similarly, the theater factors at 30 or 60 days were, identical whether the evacuation policy was 60, 90, or 120 days (15). Beebe and DeBakey recognized this limitation and advanced their theory for evacuating all patients (who would eventually require evacuation) after a fixed number of hospital days. This latter period of time was referred to as the "evacuation schedule" and was to be restricted to an estimate of the number of days before patients became transportable. The selection of any number of days as a fixed period of hospitalization, however, produces the same effect through that number of days, regardless of how short the period of time considered.

This deficiency was later overcome by the present author as applied to fixed bed accumulation factors, with the introduction of a distinctive set of evacuation probabilities for certain specified evacuation policies. These evacuee "curves" were derived by relating the number of days spent in overseas theater hospitals before evacuation to the eventual total days hospitalized for patients, by type, ultimately discharged in continental United States. Using this methodology, it was also possible to subdivide the remaining curve based upon the theoretical limitations established by the criteria for each respective evacuation policy, as it related to those patients whose eventual final disposition exceeded these limitations. Using the same methodology, it was also possible to develop similar curves for each separate type of final disposition. By summation of various portions of the remaining, evacuation, and disposition curves and through appropriate computation of these sums, it is possible to derive accumulation-decumulation factors. These factors permit time-phased estimations of dispositions among a group of patients arising from constant daily, admissions up to a point in time, after which no further admissions occur. The accumulation-decumulation factors derived from World War II and Korean War experience are current doctrine (16) for estimating fixed bed requirements and patient dispositions, but, despite Beebe and DeBakey's foresight, no further effort had been made to apply similar techniques to the estimation of mobile bed nonfixed requirements. One reason, of course, was official policy which dictated requirements for nonfixed beds be based on a basis of allocation; that is, one 60-bed surgical and two 200-bed evacuation hospitals per each division supported.

ESTIMATING PATIENT ACCUMULATIONS AND DISPOSITIONS

The probability data for patients remaining, included in appendix C, are based on the disposition of 1950-53 wounded admissions in Korea, (table C-1) and on the dispositions of 1950-53 disease and nonbattle injury admissions in all overseas areas (table C-2). These remaining figures are estimates of the probabilities that any one patient will require a hospital bed anywhere (mobile, fixed, theater, or CONUS) through the indicated number of day's after initial admission. These probabilities are called remaining factors and are, as a matter of convenience, referred to as a remaining "curve." From the properties of probability, it may be seen that summation of the remaining curve from day
one through day n  yields the average duration of hospitalization to date (day n) for patients admitted on day one. These sums are also called accumulation factors for the expected numbers of patients (based on an admission of one per day) remaining in hospital anywhere at the end of specified number of days. To adjust these total accumulations to account for evacuations, evacuee factors must be utilized. The basic data for those factors are included in appendix table C-3 for wounded patients and in table C-4 , for disease and nonbattle injury patients, for specified evacuation policies.

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These daily evacuation rates are based on the average number of days overseas before evacuation as reported on the individual evacuee report card (12) related to the total days of hospitalization to final disposition as reported on the individual medical record (4) for the same patient. These ratios have been fitted to the respective remaining probability curve based on the theoretical limitations which define the parameters for each separate evacuation policy. The evacuee factors developed from these data, therefore, are applicable only to those patients admitted overseas and to whom the eventual final disposition is either a disability separation, or, which exceeds a specified number of hospital days as stated by the respective evacuation policy.

Estimates of patient accumulations are usually made to coincide with certain specified periods of time. The intervals between these time-periods are referred to as periods of estimate and usually are of equal lengths of time. For planning purposes, the typical periods of estimate are stated in intervals of 30 days. For any period of estimate, however, and for any length of evacuation policy, it is possible to develop factors for estimating patient accumulation and disposition, based on the overall duration of stay anywhere and the duration of stay before evacuation. When a group of patients are accumulated from constant daily admissions up to a stated point in time and then decumulated through estimated dispositions over intervals of time, the resultant figures are referred to as accumulation-decumulation factors. Figure 13 provides a graphical description of both the accumulation and accumulation-decumulation process. A more complete description, however, is provided in appendix A.

SUBDIVIDING THE REMAINING CURVE

The remaining curve essentially presents the probability of patients' remaining in hospital anywhere, as a function of time after the day of admission to hospital. Patients remaining, therefore, are but one of a set of distribution functions. Besides patients remaining, the various types of disposition overseas are duty, death, and evacuation. These various distributions apply to both field army and to COMMZ (Communications Zone) of overseas theaters. Theater evacuation to CONUS converts into a patient remaining category for overseas admissions hospitalized in CONUS, in addition to disability separations which are considered only at that echelon.

The shifting of patients remaining by echelon, as the remaining curve is subdivided, may be visualized from figure 14. That segment of the remaining curve (R) through point (fN ) indicates patients remaining anywhere through the number of days of the field army evacuation, policy (f). The curve Rf indicates the proportion who are remaining in field army nonfixed beds through the number of days of the field army evacuation policy (f). And the curve OA represents the proportion remaining in theater fixed beds, while the curve OB represents the proportion remaining in CONUS fixed beds through the same number of days (f). The segment of the remaining curve fN pN represents patients remaining anywhere, between the number of days of the field army evacuation policy (f) and the length of days of the theater evacuation policy (p). The curve Ap indicates the proportion who are remaining in theater fixed beds during this period while the curve BpN indicates the proportion in CONUS fixed beds. The balance of the remaining curve (pN R_i), following the number of days of the theater evacuation policy (p), represents only evacuee patients remaining in CONUS fixed beds. The respective proportions represented by curves OA and OpN are developed from patient evacuation curves for varying lengths of evacuation policy (see figure 15 for wounded patients) and can be applied either to the field army or to overseas. theaters, or to both.