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The diagnosis of pulmonary embolism (PE) may be difficult to establish in trauma patients, particularly those who are unresponsive or mechanically ventilated. Based on a prior retrospective study, we hypothesized that patients monitored by continuous pulse oximetry who experienced a 10% or greater sudden sustained drop in arterial oxygen saturation (SaO2) without a change in static lung compliance (Cst) were most likely to have had a PE. We followed SaO2 in 972 patients admitted to our trauma ICU during the 18-month period ending in December 1990. Forty-eight patients (5%) with SaO2 changes, but no Cst changes, were evaluated for suspected PE using pulmonary arteriography (PA). Of these, 21 (44%) had a positive PA study. All patients with a positive PA had either clear chest roentgenograms or no change in underlying pulmonary pathologic processes. Of the remainder, 26 had evidence of a new pathologic entity on chest roentgenograms and only one patient had a SaO2 decrease, no change in Cst, and a negative PA. All mechanically ventilated trauma patients should have SaO2 monitored continuously. Patients with a > 10% drop in Sao2 with no change in Cst and no new roentgenographic chest findings should undergo PA. Based on our experience, this approach would yield a sensitivity, specificity, and predictive value of 100%, 99.9%, and 95%, respectively, for the diagnosis of clinically significant PE.

The identification of unstable cervical spine injury (UCSI) in blunt high-energy transfer injury (BHETI) patients is critical to management. In a prospective study of BHETI patients identified to be at high risk for UCSI, the use of lateral cervical spine view (LCV), three-view cervical spine series (FCS), and limited computerized tomography (CT) in the initial evaluation of these patients was analyzed. Thirteen of 204 patients sustained UCSI. Sensitivity of the LCV alone was 0.85 and the predictive value of the negative test was 0.97. Sensitivity and predictive value of a negative study were maximized by the use of FCS combined with CT when plain X-rays were inadequate. We conclude that technically adequate, normal FCS can be safely used to eliminate the presence of UCSI. If these studies are technically inadequate, the addition of a limited CT can be used to "clear" the spine.

Delay in diagnosis of musculoskeletal injury in multiply injured patients may potentially lead to functional or cosmetic disability in survivors. In an 18-month prospective study to determine the incidence and spectrum of delayed recognition of skeletal injury at our Level I trauma center, delayed diagnosis of 39 fractures was made in 26 of 1,006 consecutive blunt trauma patients. The delay in recognition ranged from 1-91 days. Twenty-one (55%) of the fractures were not X-rayed at the time of admission, but nine (23%) fractures were clearly visible on admission films. Four (10%) fractures were missed because of technically inadequate X-rays, and five (13%) had adequate X-rays but could not be identified on admission films. In only two instances was a second anesthetic exposure required for operative therapy. For the patients in this series, the delay of fracture identification was not felt to contribute to additional long-term cosmetic, functional, or neurologic problems. Continued clinical and radiologic surveillance is required in multiply injured patients to prevent musculoskeletal diagnostic failure.

All institutional reimbursement for inpatient care in the State of New Jersey is administered by the DRG methodology (Prospective Payment System). This system is essentially identical to federal Medicare. In 1983 our hospital was designated the Level I trauma center for southern New Jersey (population, 2.6 million). Prehospital triage guidelines based on anatomic injury were implemented, and, as a result, an annual 30% increase in severe trauma cases (ISS > 16) was realized. In late 1984 serious financial shortfalls were noticed, especially in the higher ISS cases. A 1-year study (1985) of all patients admitted through the Trauma Center to an intensive care unit was completed (523 patients; mean ISS, 15.16; ISS > 16, 37.8%). All patients were stratified to one of five ISS groups (A: ISS 1–8; B: ISS 9–15; C: ISS 16–24; D: ISS 25–40; E: ISS > 40). Average cost, reimbursement, ISS, LOS, and mortality were reviewed for the entire aggregate and each severity group. The system of ISS grouping was an accurate method of cost analysis, and prospectively, ISS grouping allowed prediction of length of stay and total hospital cost. In addition, these data allowed early fiscal management decisions and resource allocation. As a reimbursement system, DRG falls short of the cost of care for all ISS levels and groups. As severity of injury rose, costs increased in a linear manner, but reimbursement did not, resulting in a substantial financial loss. The net loss to the hospital in 1 year was $1.86 million. Based on this experience, DRG's are not capable of supporting trauma care, and if adopted by other state agencies or third party payors, would end the concept of the trauma center.

Data on venous injury in blunt extremity trauma are scarce. The nature of injury and results of therapy in 22 patients presenting with blunt venous extremity injury at MIEMSS and KUMC in a 10-year period are presented. Comparisons of the outcome with venous ligation and repair, the use of anticoagulants, and the use of fasciotomy, led to the development of guidelines for the therapy of blunt venous injury in both upper and lower extremity trauma.

The Abbreviated Injury Scale (AIS) and the Injury Severity Score (ISS) are objective means of assessing injury. Accepted methodology involves retrospective scoring of injury based on discharge diagnoses. Recently, early clinical scoring, supplemented by review at discharge, has been introduced. A prospective study was instituted to compare these methodologies. Four hundred sixty consecutive victims of blunt trauma were scored using both clinical and retrospective methodologies by independent, blinded observers. Of these, 333 patients had a change in ISS, 174 with a change of greater than four points. The population mean ISS remained unchanged; however, paired values were significantly different (p less than .03). We conclude that either methodology is applicable for studies of large populations of trauma victims. When accurate individual AIS or ISS scoring is required, the clinical method combined with discharge review is most appropriate.

The effect of cyclophosphamide on the transplantability of hamster tumor cells transformed by PARA-adenovirus 7 was investigated. Normally, such syngeneic transplants seldom, if ever, regress spontaneously. It was found that chemotherapy was remarkably effective against this neoplasm. A single inoculation of the drug (200 mg/kg) prevented the growth of 104-105 transplanted cells, and promoted regression of palpable tumors. Weekly drug inoculations prolonged the survival of hosts bearing large neoplasms. Animals successfully treated proved to be resistant to subsequent tumor-cell challenge. The chemical did not prevent tumor growth if given prior to the transplant. There is suggestive evidence that host tumor resistance may have contributed to the success of cyclophosphamide therapy.

IN MONGOLOID defectives, stigmas in the skeleton have been reported at several sites: hypoplasia of the base of the skull; hypoplasia of the nasal and other facial bones, and dysplasia and hypoplasia of metacarpals and phalanges. Undergrowth of the vertebral bodies and the tubular bones in the extremities is responsible for the dwarfism which is one of the most consistent components of this syndrome. Maturation of the skeleton varies greatly in different mongoloid infants; it may be advancecd, normal, or retarded. At birth practically all infants with mongolism show normal or advanced maturation, in our experience. Spitzer and Robinson found the frontal sinuses to be absent in 26 out of 28 individuals with mongolism in contrast to an absence in 4 to 5 per 100 of the remainder of the general population. Only 2 of the 28 individuals with mongolism showed no dental aplasia. The erupted teeth were commonly stunted, eruption of the permanent teeth was often delayed, and there was a higher incidence of the dental anomalies found than in the general population. No pathognomonic lesions in the teeth were found. The partial anodontia, deformed teeth and delayed eruption resemble the changes found in ectodermal dysplasia and in cleidocranial dysostosis. Smith and McKeown found the mean weights of newly born infants with mongolism to be 2860 gm. in contrast to 3220 gm. for normal newborns. the mean duration of gestation to he shorter for infants with mongolism than for normal newborns, 269 days and 278 days respectively. So far as we have been able to ascertain, stigmas in the pelvic bones of infants with mongolism have not been reported in either anatomical or roentgenographic studies.

To evaluate the hypothesis that all victims of severe blunt trauma require a pelvic radiograph, we prospectively studied all such patients admitted to the Southern New Jersey Regional Trauma Center during a seven-month period. All patients were classified as unconscious; impaired; awake, alert, and symptomatic; or alert, oriented, and asymptomatic for pelvic fracture on admission. All underwent a plain anterior-posterior radiograph of the pelvis. A total of 265 patients were studied and 26 pelvic fractures were identified. These occurred in seven of 36 unconscious patients, 11 of 96 impaired patients, and eight of 23 symptomatic patients. No fractures were identified in 110 awake, alert, oriented, and asymptomatic patients (P less than .0001). We conclude that pelvic radiographs are required in unconscious or impaired victims of severe blunt trauma and those with signs or symptoms of pelvic fractures but are not required in the awake, alert, and asymptomatic patient.

Operations research is a novel approach to the problem of making sound decisions in complex matters. Conceived during the last war by scientists helping the war effort, it has proved its usefulness in many fields, as different as hunting enemy submarines and determining optimal rates of industrial production. Very briefly, the operations research approach consists in determining one's objectives, selecting meaningful measures of achievement, formulating a mathematical model of the problem to show both the variables under control and those not subject to control, and indicating the results of alternate courses of action (2). Problems of roentgen diagnosis are many, but they do not greatly resemble those of finding hidden submersibles, except for the trying necessity of making important decisions when information available is incomplete or uncertain. The art of diagnosis is the art of evaluating equivocal evidence. Problems of patients with partial proof provide the pitfalls and pleasures of roentgen iconog...

Loosening of the prosthetic device occurs in about 5% of cases following placement of total hip prostheses (THP). Early detection of loosening is much desired but is difficult to achieve using conventional methods. Due to errors of projection, it is quite possible to fail to detect mobility of even as much as 5 mm on single x-ray films. We are attempting to develop a simplified photogrammetric system suitable for general hospital use which could detect loosening of 0.8 mm at the 95 % level of confidence without use of complex stereoplotting equipment. Metal reference markers are placed in the shaft of the femur and in the acetabular region of the pelvis at the time of surgery. The distances between these reference markers and certain unambiguous points on the prostheses are computed analytically using an X-Y acoustical digitizer (accuracy ± 0.1 mm) and software developed previously for craniofacial measurement. Separate stereopairs of the joint region are taken under weight-bearing and nonweight-bearing conditions. Differences in the measured distances between the bo-ne markers and the prosthetic components on the two stereopairs are taken as indicators of prosthesis loosening. Measurements on a phantom using ten different x-ray stereopairs taken from as many different perspectives have established that true linear distances between reference points and prostheses can be measured at the desired reliability with the present low precision system. Preliminary in vivo measurements indicate that the main unresolved problem is the movement of the subject between the two exposures of each single stereopair. Two possible solutions to this problem are discussed.

Unstable injury of the cervical spine must be considered in all victims of blunt trauma. To evaluate the role of limited, directed computed tomography (CT) in the initial evaluation of the cervical spine, a one-year study involving 104 high-risk patients was undertaken. Sensitivity was 0.78 overall, but in the group of patients scanned after inadequate plain radiographs, CT had a sensitivity of 1.0 for unstable cervical injury. All false-negative studies involved atlantoaxial rotary subluxation. We conclude that limited, directed CT of the cervical spine is appropriate in the initial evaluation of patients at risk, particularly if plain radiographs are inadequate, but is of limited value in the evaluation of ligamentous injury of the upper cervical spine.

Abstract The hydraulic fracture stimulation of low permeability reservoirs has been a successful technique permeability reservoirs has been a successful technique for obtaining economic hydrocarbon production from many otherwise marginal fields. The analysis of pressure transient data obtained in hydraulically fractured wells has been previously published by many authors. published by many authors. This paper utilizes these published theories for the purpose of illustrating that data from wells in a California Oil Field can be analyzed with the results used to guide future development. Introduction The results of the analysis of pressure transient data from wells in a California Oil Field is presented in this study. Hydraulic fracture stimulation presented in this study. Hydraulic fracture stimulation treatments are necessary for the producing wells to achieve economic oil production rates. An extensive well testing program in the subject field was conducted in an attempt to obtain reservoir characteristics that would assist in the development of the field on closer well spacing. High quality data was obtained for analysis by implementing the following testing program:Pressure drawdown and build-up tests on a new infill well (Well C) that had not been hydraulically fracture stimulated.Interference well tests utilizing two previously hydraulically fractured offset wells (Wells SW and SE) as pulsing wells and the new infill well (Well C) as an observation well.An interference well test in which the new infill well (Well C) was hydraulically fracture stimulated while four offset shut-in observation wells (Wells NW, SW, NE, and SE) were utilized to record reservoir pressure response.A post-fracture stimulation well test of the new infill well (Well C). High - precision electronic pressure gauges attached to an electric line enabled on-site analysis to be made during the field testing. Pressure data was recorded as frequently as Pressure data was recorded as frequently as five-second time increments during critical periods to enable an accurate analysis to be obtained. GEOLOGY AND RESERVOIR CHARACTERISTICS The subject field that was evaluated is located in the San Joaquin Valley of California. The hydrocarbon fluids in this field are contained in a Miocene Age Porcellanite Formation that consists of relatively high porosity (−30%) and relatively low permeability (−0.1 md). A reservoir oil of approximately 390 API oil gravity is produced from the formation with significant amounts of hydrocarbon gas. A saturated oil viscosity of 0.5 cp was measured in the laboratory at initial reservoir conditions of 170 degrees F and 3000 PSIA. PSIA. The reservoir oil has a formation volume factor of approximately 1.5 RVB/STB and contains approximately 500 SCF/STB of dissolved solution gas. Although the reservoir oil was determined to exist at bubble point conditions, no gas cap was initially present in the field. present in the field. WELL COMPLETION Figure I illustrates a cross-section of the reservoir with an average vertical thickness of 300 feet existing in the field. The upper 200 feet of the formation is usually perforated for oil production in an attempt to reduce the risk of production in an attempt to reduce the risk of bottom water entry after hydraulic fracture stimulation treatments. A total of 31 wells have been drilled and completed by Chevron in the subject field. These wells must be hydraulically fracture stimulated to achieve economic production rates.

Estimates of the incidence of injury to the cervical spine among patients suffering blunt trauma to the head vary widely, and have been reported to be as high as 20%. Since strict observation of cervical spine precautions may delay attempts to gain control of the airway in a patient with an intracranial injury, the risk involved needs more exact definition. In an attempt to quantify this risk, the records of 1,272 consecutive patients with blunt injuries admitted to a Level I regional trauma center were reviewed. Patients with serious craniocerebral injury were at no greater risk for injury to the cervical spine than patients without trauma to the head (1.8% vs. 3.5%, p = NS by Chi-square analysis). Although observance of cervical spine precautions is usually paramount, there may be times when this concern is superceded by the need to gain definitive airway control in a patient with injury to the brain.

During a 1-year period, three patients presented with acute traumatic thrombosis of the common or external iliac artery concomitant with a massive crush injury to the pelvis. All had vascular compromise of the involved extremity on initial physical examination, but in two patients with open pelvic trauma, exsanguination, major visceral injury, hypothermia, and a coagulopathy precluded emergency vascular reconstruction. Both required hindquarter amputation for adequate debridement. The third patient presented without exsanguination or visceral trauma. Angiography and vascular reconstruction were undertaken, but myonecrosis compounded the initial vascular compromise, and eventually required a hip disarticulation for debridement. It was concluded that: exsanguination and/or major visceral injury takes priority over emergency vascular reconstruction; soft-tissue injury may preclude limb salvage despite vascular reconstruction. If a cadaveric limb exists, early radical amputation, including hindquarter amputation, should be undertaken.

One greater delight than teaching medicine is learning it. Students, teachers, and society of which they are a part have much to gain from a new tool of learning: programmed instruction. It promises to introduce a new degree of ease, effectiveness, and efficiency into the initial and continuing training of physicians. The engineering approach is the art of applying scientific knowledge to tasks of living: building roads, lighting rooms, heating houses. We did build roads, light rooms, and heat houses without the help of engineers, but it was not the same. Human engineering is the art of designing objects that serve their users with ease—a knife that fits the hand that cuts, an instrument panel that reveals rather than confuses. It is based on careful attention to the limitations and capabilities of humans as users of objects and services. Programmed instruction represents a human engineering-type of approach to teaching. Good

Education in radiological science relates to the need for significant instruction in areas of radiology other than film diagnosis, clinical nuclear medicine, or radiation therapy. This subject material can be effectively presented in a multipurpose unit in which several different categories of students may be instructed in various branches of radiology. The design and operation of one such type of unit is presented, together with the program outline for specific groups such as residents, technologists, and medical students. Education in this area may be the most important mechanism for promoting the efficient use of ionizing radiations in medicine.

In a pilot program the authors investigated the feasibility of training technologists to screen survey chest roentgenograms. After a training program and guided practical experience, the results of testing indicated that the interpretations of these radiologic assistants compare favorably with those of the staff radiologists, senior residents, and those reported in the literature.

Fluoroscopic examinations can be recorded on television tape at low radiation levels making possible better teaching and training of young radiologists and better service to referring physicians.Important findings can be recorded photographically from the image on the monitoring screen during a subsequent playback of the recorded tape (photographic spot films), at a small cost and with no added radiation to the patient. Photographic spot films on 35 mm. film can be processed in regular automatic x-ray processors, with no special equipment or personnel. These filmstrips are filed in special envelopes within the regular radiographic folder of each patient (Fig. 6).

The Radiologic Learning File is a means of radiologic self-instruction for residents and is a training aid to clinical medicine and radiology for undergraduates. Approximately 1,200 clinically and pathologically documented roentgenographic cases ideally arranged for efficient learning illustrate practical diagnostic problems. Normal and abnormal studies are constantly compared, and varied disorders with similar roentgen manifestations are examined consecutively to highlight distinguishing features. As a supplement to early clinical training, the Learning File experience should increase learning efficiency comparable to that resulting from exposure to a random flow of patients.

Nonoperative management of blunt injury to the spleen in adults has been applied with increasing frequency. However, the criteria for nonoperative management are controversial. The purpose of this multi-institutional study was to determine which factors predict successful observation of blunt splenic injury in adults.A total of 1,488 adults (15 years of age) with blunt splenic injury from 27 trauma centers in 1997 were studied through the Multi-institutional Trials Committee of the Eastern Association for the Surgery of Trauma. Statistical analysis was performed with analysis of variance and extended chi2 test. Data are expressed as mean +/- SD; a value of p0.05 was considered significant.A total of 38.5 % of patients went directly to the operating room (group I); 61.5% of patients were admitted with planned nonoperative management. Of the patients admitted with planned observation, 10.8% failed and required laparotomy; 82.1% of patients with an Injury Severity Score (ISS)15 and 46.6% of patients with ISS15 were successfully observed. Frequency of immediate operation correlated with American Association for the Surgery of Trauma (AAST) grades of splenic injury: I (23.9%), II (22.4%), III (38.1%), IV (73.7%), and V (94.9%) (p0.05). Of patients initially managed nonoperatively, the failure rate increased significantly by AAST grade of splenic injury: I (4.8%), II (9.5%), III (19.6%), IV (33.3%), and V (75.0%) (p0.05). A total of 60.9% of the patients failed nonoperative management within 24 hours of admission; 8% failed 9 days or later after injury. Laparotomy was ultimately performed in 19.9% of patients with small hemoperitoneum, 49.4% of patients with moderate hemoperitoneum, and 72.6% of patients with large hemoperitoneum.In this multicenter study, 38.5% of adults with blunt splenic injury went directly to laparotomy. Ultimately, 54.8% of patients were successfully managed nonoperatively; the failure rate of planned observation was 10.8%, with 60.9% of failures occurring in the first 24 hours. Successful nonoperative management was associated with higher blood pressure and hematocrit, and less severe injury based on ISS, Glasgow Coma Scale, grade of splenic injury, and quantity of hemoperitoneum.

Shadows are but dark holes in radiant streams, twisted rifts beyond the substance, meaningless in themselves. Man—warm, lively, fleshy man—and his story are both root and key to his shadows; shadows cold, silent, and empty. John Caffey The bold, brave, boyishly boastful slogan of the United States Army Corps of Engineers, “The difficult we do immediately—the impossible takes a little longer,” may well apply to diagnostic radiologists. From visual clues often barely perceptible they extract knowledge that is safe, sound, significant, and satisfying much of the time. Pathologists, fellow students of organs altered by disease, do not regularly risk their reputations with reports resting on gross morbid changes alone, even though their pieces of evidence are polychromatic and substantial, and can be felt, smelled, weighed, and cut or caressed with a knife. What is the secret of drawing valid conclusions from shadow to substance with a frequency that is astonishing and delightful? The secret is simple though n...

The diagnostic radiologist is a clinical consultant who is expected to help the referring physician help his patients. How is this best accomplished? In a recent paper, 1 Dr. Max Ritvo of Boston discussed this topic in what amounted to a whirlwind tour of diagnostic radiology, its past, its present, its accomplishments, its future. Accomplishments were emphasized. If there is some truth in the playful but painful confession we make to our students at graduation time, that about half of what we taught them is untrue—but we cannot tell which half—Dr. Ritvo was charitably silent about it. But he also discussed some of the limitations of roentgen diagnosis. Ordinarily, little is said about this, yet knowledge of the limitations of one's method is important knowledge. Owen H. Wangensteen once wrote that "the limitation of a method constitutes no reflection upon its user, save in so far as he fails to

To the Editor:— The article by L. E. Harris and associates on the early diagnosis of congenital dislocation of the hip in The Journal, May 21, page 229, and the letter of F. K. Alexander questioning the wisdom of this work because it involved roentgenologic examination of many infants, in The Journal, Aug. 6, page 1616, raise questions of medicine, language, logic, and moral philosophy, all fascinating in different ways.Congenital dislocation of the hip is a crippling disease, difficult to understand and often difficult to diagnose. The results of treatment are often gratifying but cannot be predicted. How effective therapy is no-one knows since there is no general agreement on what constitute "early" or "minimal" or "slight subluxation" cases. Caffey and his group at Babies Hospital, Columbia University, have shown that traditional criteria used in predicting dislocation are unreliable (Pediatrics17:632 [May] 1956); asymmetrical gluteal folds, limitation of

To the Editor:— To know is to foresee and to write is to teach; to give percentages in a medical paper is to do all of these. When one reads that "of 16 patients with carcinoma of the pancreas 6.3% exhibited bone metastases" one expects 6.3% of the next 100 patients with carcinoma of the pancreas to exhibit the same phenomenon; this is what the author must have meant. From his 16 patients he knows what will happen to the next 100 (this is what the term per centum implies; it is a forecast), and he goes out of his way to save his reader the trouble of figuring. The reader is actually being uncooperative by doing the calculations again to find that 6.3% of 16 patients is one patient. The author may want to help the reader make comparisons by saying that the x-ray examination was correct in 60%

Teaching medicine is a profession and a pleasure, a vocation and an avocation. It is also, as current research convincingly shows, a form of behavior that can be studied, measured, and modified under controlled conditions.1-3 General educational research has an active and growing national organization, the American Educational Research Association (AERA), which produces informative reviews of current work through theReview of Educational Research, has developed anEncyclopedia of Educational Research, and, in theHandbook of Research on Teaching, has created what is "likely to be voted the most influential educational book of the half century."4 Research in medical education is a relatively new field of endeavor. Although the Association of American Medical Colleges has supported such systematic study for more than a decade, educational research is formally represented in the organizational pattern of only seven medical schools; the oldest of these programs was established in 1959. Other

To the Editor:— The emphatic views of Dr. Sidney Bolter on "The Misuse of Sympathy" (Medicine at Work, J. A. M. A. 172 :335 [Jan. 23] 1960) appear to be entirely original; I know no other doctor who feels that sympathy has little place in the practice of medicine. Dr. Bolter writes as a psychiatrist, but reading his paper ( J. Michigan M. Soc. 57 :1708, 1958) leaves one with the impression that he has the entire practice of medicine in mind when he writes: "Unfortunately sympathy is not a scientific instrument. It cannot be dispensed in any measurable amount, kill bacteria, remove or alter the function of diseased organs, immunize against ill health, and, above all, it cannot foster psychological growth and maturation. Under the psychiatric microscope, sympathy can only be viewed as being saprophytic, feeding on emotional decay." Medicine has long been held back in its development by people