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A rapid computed tomography technique or "trauma scan" (TS) provides high-resolution studies of the head, cervical spine, chest, abdomen, and pelvis. We sought to determine whether TS has decreased missed injuries. A previous study of TS found a 3% missed rate.After institutional review board approval, trauma patients from January 2001 through December 2008 were reviewed for delayed diagnosis (DD) of injury to the head, cervical spine, chest, abdomen, or pelvis. Missed extremity injuries were excluded. Injury Severity Score, length of stay, type of injury, outcomes, and days to detection were captured.Of 26,264 patients reviewed, 90 patients had DD, with an incidence of 0.34%. DD most commonly presented on day 2. Injuries included 16 bowel/mesentery, 12 spine, 11 pelvic, 8 spleen, 6 diaphragm, 5 clavicle, 4 scapula, 4 cervical spine, 4 intracranial, 4 sternum, 3 maxillofacial, 3 liver, 2 heart/aorta, 2 vascular, 2 urethra/bladder, 2 pneumothorax, and 2 pancreas/common bile duct. DD resulted in 1 death, 6 prolonged intensive care unit stays, 19 operative interventions, and 38 additional interventions.TS is an effective way of evaluating trauma patients for intracranial, cervical spine, chest, abdomen, and pelvic injuries that have the potential to impact morbidity and mortality. The incidence of injuries missed in these crucial areas has been reduced at our institution by the use of this radiographic modality. The most common missed injury remains bowel, and so a high index of suspicion and the tertiary survey must remain a mainstay of therapy.

Minimally invasive surgery has found many applications in general surgery. The role of laparoscopy in trauma has been debated as a diagnostic, as well as therapeutic, tool in hemodynamically stable patients. This study evaluated laparoscopy in the trauma population. A retrospective review of all laparoscopies performed in hemodynamically stable trauma patients from 1996 until 2006 was conducted. Mechanisms of injury, perioperative data, and demographic variables were analyzed using descriptive statistics and Student's t test. Exploratory diagnostic laparoscopy was performed on 102 patients. Laparoscopy was negative for 65 per cent of patients; 12 per cent of these were converted to laparotomy due to adhesions, hemoperitoneum, or surgeon preference. None of the conversions revealed intra-abdominal injury at laparotomy. An injury was diagnosed at laparoscopy in the remaining 35 per cent, with 55 per cent conversion rate to repair the injury. Therapeutic laparoscopy included serosal repair, hemorrhage control, diaphragmatic repair, and other standard laparoscopic treatments. No patient required re-exploration, there were no missed injuries or other complications, and no patient died in this study. Laparoscopy has an important diagnostic and therapeutic role in selected hemodynamically stable trauma patients. Using a minimally invasive approach can reduce the potential morbidity of negative laparotomy.

Trauma during pregnancy places two lives at risk. Knowledge of risk factors for trauma during pregnancy may improve outcomes.We reviewed the charts of 188 such patients admitted to a Level I trauma center from 1996 to 2004. A comparison was made of injury severity and outcome from a cohort of nonpregnant female trauma patients selected with a similar temporal occurrence and age range.Motor vehicle collisions comprised 160 cases, 67 using a restraint device. Of 84 patients tested, 45 tested positive for intoxicants, 16 positive for 2 or more intoxicants. A significant trend toward less testing through the study period was observed (p = 0.0002). Injury severity was assessed by Revised Trauma Score (RTS). RTS11 or admission to operating room or intensive care units (OR/ICU) classified patients as severely injured. The six maternal fatalities had an RTS11 or OR/ICU disposition. Fetal outcomes included 155 live in utero, 18 live births, and 15 fatalities correlating with injury severity by either criteria (p0.0001). Of the fetal fatalities, 7 occurred with RTS = 12, but only 3 fatalities occurred in the 147 cases not admitted to OR/ICU. Gestational age correlated (p0.0001) with fetal outcomes. The 18 live births had mean gestational ages of 35 +/- 4 weeks as compared with fetal fatalities at 20 +/- 9 weeks, and fetuses alive in utero at 22 +/- 9 weeks gestation. Coagulation tests prothrombin time (PT), international normalized ratio (INR) (both p0.008), and partial thromboplastin time (PTT) (p0.0001) correlated with maternal outcome. A matched cohort of nonpregnancy trauma cases during the same time frame indicated that, despite a significantly higher percentage of severely injured patients, fewer fatalities occurred. This might reflect a greater risk for the pregnant trauma patient.This study of trauma in pregnancy cases revealed a high percentage with risk behaviors. There was a significant trend toward less intoxicant testing in recent years. Coagulation tests were the most predictive of outcomes. Lower gestational age correlated with fetal demise.

Although it may be apocryphal, it is said that the Chinese have a curse that states, “May you live in interesting times.” We live in interesting times. Hospitals across the country are facing financial difficulty and trauma centers are the first area examined for closure. Trauma centers in Pennsylvania, West Virginia, and Las Vegas have closed, at least temporarily, because of problems with specialist coverage. The insurance crisis in many of our states has created a situation where even physicians who are willing to care for trauma patients cannot get professional liability coverage, forcing them to either move to more physician friendly states, to come up with new alternatives such as physician or specialty owned carriers, or even to go bare. A flaw in the Medicare reimbursement formula has lead to a 10% decrease in physician payments over two years. And, even though Medicare does not pay a large role in trauma reimbursement, we all know that as Medicare does, other carriers rapidly follow. Leapfrog and other consumer groups are demanding “quality care” and are determining what that quality is, whether we agree with it or not. This quest for quality has lead to the 80 hour workweek for residents, which leads us to wonder how we will do the work we need to do and says nothing of how we will educate residents with these limitations. Finally, despite these restrictions, we still face the issue that medical students are not choosing surgical residencies as they did before, and surgical residents are not choosing trauma fellowships for training. How can trauma surgery and trauma surgeons survive in the current economic environment of medicine? Surely there have never been such interesting (and dangerous) times for our field? As most presidents do in preparing their presidential addresses, I went back and reviewed the addresses of my predecessors to gain historical perspective and to reexamine their wisdom. In doing that, I learned once again that there are no new problems in medicine—whatever problems appear new at the time have almost certainly been considered in the past, even if the tools were not available to address them. This also applies to the problems I am considering today. Our first president, Kimball Maull, talked about the disconnect between the public perception of trauma and the actual problem that trauma presents to society. Our second president, Burton Harris, talked about the problems of the redefinition of surgery and the surgical specialties, the lack of interest of many surgeons in doing trauma, and most fearsome of all, the evil effects of business on the field of medicine. Len Jacobs talked about the forces of diversification and specialization which were affecting trauma care and noted that “Uncompensated trauma care and maldistribution of trauma centers Submitted for publication May 7, 2003. Accepted for publication May 12, 2003. Copyright © 2003 by Lippincott Williams & Wilkins, Inc. From the Division of Trauma/Critical Care, University of Tennessee Medical Center, Knoxville, Tennessee. Presidential address presented at the 16th Annual Scientific Assembly of the Eastern Association for the Surgery of Trauma, January 15–18, 2003, Ft. Myers, Florida. Address for correspondence: Blaine L. Enderson, MD, MBA, FACS, FCCM, Professor of Surgery and Chief, Division of Trauma/Critical Care, University of Tennessee Medical Center at Knoxville, Department of Surgery, University Memorial Hospital, 1924 Alcoa Highway, Knoxville, Tennessee, 37920-6999; email: benderso@utk.edu.

Purpose: The surgical resident experience with trauma has changed. Many residents are exposed to predominantly nonoperative patient care experiences while on trauma rotations. Data from a large multicenter study were analyzed to estimate surgical resident exposure to trauma laparotomy, diagnostic peritoneal lavage (DPL), and focused abdominal sonography for trauma (U/S). Methods: Centers completed a self-report questionnaire on their institutional demographics, admissions, and procedure for a 2-year period (1998-1999). Results: A total of 82 trauma centers that provide resident teaching were included. The included centers represent over 247,000 trauma admissions. The majority of trauma centers (65.9%) had > 80% blunt injury. Although all centers performed laparotomies, other results were more variable. For U/S, 24.2% performed none at all and 47.0% performed fewer than two U/S examinations per month. For DPLs, 3.8% performed none and 66.7% performed fewer than two per month. Assuming 1 night of 4 on call, the average surgical resident training at a trauma center performing > 80% blunt trauma has the potential to participate in only 15 trauma laparotomies, 6 diagnostic peritoneal lavages, and 45 ultrasound examinations per year. In addition, the resident will care for an average of 500 blunt trauma patients before performing a splenectomy or liver repair. Conclusion: Surgical resident experience on most trauma services is heavily weighted to nonoperative management, with a relatively low number of procedures, little experience with DPL, and highly variable experience with ultrasound. These data have serious implications for resident training and recruitment into the specialty.

Background: Proinflammatory eicosanoids formed from arachidonic acid (AA) by lipoxygenase (LO) and cyclooxygenase (COX) pathways have been shown to inhibit apoptosis in certain cell types. This study determined whether inhibition of LO and COX increased apoptosis in AA-treated HL-60 cells in vitro. Methods: HL-60 cells were incubated with 50 μmol/L AA and an enzyme inhibitor (1-10 μmol/L) for COX, LO, 12-LO, and 5-LO for 12 hours. Flow cytometry was used to assess viability, apoptosis, and necrosis. Apoptosis was further assessed using terminal dUTP nick end-labeling and DNA fragmentation. Results: The highest concentration of LO inhibitors, but not COX inhibitors, decreased viability and increased apoptosis and necrosis in the presence of exogenous AA. Conclusion: These results suggest that disruption of the metabolism of AA by LO, in particular 5-LO, decreases cell survival and increases apoptosis. Thus, downstream metabolic processing of AA by LO but not COX plays a critical role in the regulation of HL-60 cell apoptosis.

Enteral nutrition with eicosapentaenoic acid (EPA; 20:5 n-3) and gamma-linolenic acid (GLA; 18:3 n-6) decreased pulmonary inflammation by reducing neutrophil counts and chemotactic factors in bronchoalveolar lavage fluid during acute respiratory distress syndrome (ARDS). We hypothesize that the anti-inflammatory effects of EPA and GLA may be due, in part, to induction of neutrophil apoptosis. The purpose of this study was to determine whether EPA and GLA, alone or in combination, trigger apoptotic cell death in the human promyelocytic leukemia HL-60 cell line. HL-60 cells were incubated with 10, 20, 50, and 100 micromol/L EPA, GLA, or various combinations of EPA and GLA for 2, 4, 8, 12, and 24 hs. Oleic acid (18:1 n-9) was used as a fatty acid control. Flow cytometry using dual staining with propidium iodide and annexin V-FITC assessed apoptosis, necrosis, and viability. Apoptosis was verified by DNA fragmentation as assessed by agarose gel electrophoresis. EPA, GLA, and various combinations of EPA and GLA significantly induced apoptosis and reduced cell viability in HL-60 cells. Viability was significantly reduced to the same extent with the combination of 50 micromol/L EPA\20 micromol/L GLA compared with 100 micromol/L EPA. These data indicate that EPA and GLA, alone or in combination, reduce cell survival by induction of apoptosis. Thus, induction of apoptosis by select dietary n-3 (EPA) and n-6 (GLA) polyunsaturated fatty acids may be the mechanism of the resolution of pulmonary inflammation in ARDS.

BACKGROUND There is a dearth of clinical data regarding the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on long-bone fracture (LBF) healing in the acute trauma setting. The orthopedic community believes that the use of NSAIDs in the postoperative period will result in poor healing and increased infectious complications. We hypothesized that, first, NSAID use would not increase nonunion/malunion and infection rates after LBF. Second, we hypothesized that tobacco use would cause higher rates of these complications. METHODS A retrospective study of all patients with femur, tibia, and/or humerus fractures between October 2009 and September 2011 at a Level 1 academic trauma center was performed . In addition to nonunion/malunion and infection rates, patient records were reviewed for demographic data, mechanism of fracture, type of fracture, tobacco use, Injury Severity Score (ISS), comorbidities, and medications given. RESULTS During the 24-month period, 1,901 patients experienced LBF; 231 (12.1%) received NSAIDs; and 351 (18.4%) were smokers. The overall complication rate including nonunion/malunion and infection was 3.2% (60 patients). Logistic regression analysis with adjusted odds ratios were calculated on the risk of complications given NSAID use and/or smoking, and we found that a patient is significantly more likely to have a complication if he or she received an NSAID (odds ratio, 2.17; 95% confidence interval, 1.15-4.10; p < 0.016) in the inpatient postoperative setting. Likewise, smokers are significantly more likely to have complications (odds ratio, 3.19; 95% confidence interval, 1.84-5.53; p < 0.001). CONCLUSION LBF patients who received NSAIDs in the postoperative period were twice as likely and smokers more than three times likely to suffer complications such as nonunion/malunion or infection. We recommend avoiding NSAID in traumatic LBF. LEVEL OF EVIDENCE Epidemiologic & therapeutic study; level II.

Background: The differentiation of duodenal perforation from duodenal hematoma is not always possible with computed tomography (CT). Our diagnostic guideline has included duodenography to investigate CT findings of periduodenal fluid or wall thickening. However, the utility of duodenography as a diagnostic study in blunt abdominal trauma is not defined. We evaluated duodenography as a diagnostic test in patients with suspected blunt duodenal injuries (BDIs). Methods: During a 10-year period, 96 patients out of 25,608 trauma admissions had CT findings of possible BDI and underwent duodenography. Demographic and clinical data, diagnostic methods, and management were derived from prospectively collected data. CT and duodenography studies were reviewed and correlated with surgical findings and outcome. All CT scans were obtained with intravenous contrast; oral contrast was used in 32 patients. Duodenography was analyzed using the 2 x 2 method and Bayes theorem. Results: Indications for duodenography included periduodenal fluid without extravasation (76%), abnormal duodenal wall thickening (16%), and retroperitoneal extraluminal gas (5%). Eighty-six duodenography studies were reported as normal, six were consistent with hematoma, one was indeterminate, and only three revealed extravasation. Two of these three patients with duodenal perforation had retroperitoneal extraluminal air. Only one patient underwent exploration on the basis of duodenography. No blunt duodenal perforation was diagnosed by CT. Overall, duodenography had sensitivity of 54% and specificity of 98%. For BDIs requiring repair, duodenography sensitivity was only 25%; the false-negative rate was also 25%. Retroperitoneal extraluminal air was a useful sign of duodenal perforation, occurring in two of three patients with BDI and only in one without BDI (p < 0.001). Conclusion: Duodenography has a low sensitivity in patients with suspected BDI by CT findings and is of minimal utility in diagnostic evaluation. Retroperitoneal extraluminal air seen on CT is an important sign of BDI requiring surgical repair.

Background . Tracheobronchial injuries are encountered with increasing frequency because of improvements in prehospital care and early initiation of the Advanced Trauma Life Support protocol. We review our experience with these injuries with the hypothesis that the leading determinant of patient outcome is the time interval to diagnosis. Methods . Patients with tracheobronchial injury were identified from the registry of our level 1 trauma center during a 10-year period ending December 1997. Clinical presentation, diagnostic evaluation, surgical management, and outcome were reviewed. Results . Twenty patients with ten cervical tracheal injuries and ten intrathoracic tracheobronchial injuries were treated. The mechanism of injury involved blunt trauma in 11 and penetrating trauma in 9. All patients underwent surgical debridement and primary repair. Patients with isolated airway injuries were discharged home after a mean hospital stay of 6 days and had no early complications. Three patients had delayed diagnosis (> 24 hours), and all sustained complications including death (1 patient) and multiorgan system failure (2 patients). The overall mortality rate was 15%. Conclusions . Operative management of tracheobronchial injuries can be achieved with acceptable mortality. Independent of mechanism or anatomic location of injury, delay in diagnosis is the single most important factor influencing outcome. Early recognition of tracheobronchial injury and expedient institution of appropriate surgical intervention are essential in these potentially lethal injuries.

A previous report from the authors' institution reported the effectiveness of hepatic packing with absorbable fine mesh (AFMP) for the control of hemorrhage in an animal model with an otherwise lethal hepatic injury. The technique has subsequently been applied to 12 abdominal trauma patients with hemodynamic instability and actively hemorrhaging hepatic injuries. Two patients expired in the operating room owing to uncontrolled hemorrhage from hepatic and associated injuries for a mortality of 16.7%. AFMP was successful in controlling hemorrhage in the remaining 10 patients. Hepatic injuries ranged from grade II to grade V, and all were actively hemorrhaging at the time of exploration. None of the surviving 10 patients experienced early or late recurrent bleeding attributable to the hepatic injuries, and there were no intraabdominal abscesses or late deaths. Liver function studies returned to normal prior to discharge in all surviving patients. Follow-up included serial computed tomographic scans, which demonstrated fibrosis incorporating the mesh packing. Complete resolution of injury and mesh appears to proceed over approximately a 6-month period. AFMP is a safe, effective method for controlling hepatic hemorrhage. It is easy to perform in the operating room, offers an excellent matrix for hemostasis, provides tamponade of bleeding sites, and does not require reoperation for removal of packing material, as is necessary with conventional, nonabsorbable packing techniques.

BACKGROUND Trauma physician reimbursement at many trauma centers is based on an academic or employed model. However, private practice is also used, especially at community-based trauma centers. Commercial insurance companies acknowledge that trauma care should be reimbursed at a higher rate than elective practice, but they often lack the ability to separate these lines of business. Federal law also prevents groups that are not integrated from shared negotiation. The objective of this study was to develop a model for private practice billing that provides increased reimbursement for trauma line of business. METHODS The hospital created a trauma contracting organization. This organization contracted with the hospital and insurance companies to deliver trauma care. It obtained fee schedules for trauma care that were greater than for elective surgical care. It then contracted with trauma physicians to deliver trauma care using those fee schedules and its provider number. Data from 2009 were evaluated to determine the impact. RESULTS Reimbursement rates were evaluated for multiple carriers and compared between the trauma contracting organization and the standard practice. Rate of reimbursement for self-pay patients and government carriers (Medicare, Medicaid, and Champus) were the same for both: 7% of charges for self-pay and 25% of charges for government carriers. Commercial carriers provided increased reimbursement for the trauma line of business, averaging 7% to 10% more return on charges. The annualized impact was over $300,000 more reimbursement on over $5,000,000 in charges. CONCLUSION This model can provide a means to increase reimbursement for trauma care in a private practice environment.

The multiply injured trauma patient presents a diagnostic and therapeutic challenge: that of discovering all injuries while simultaneously proceeding with resuscitation and maintaining life. Many factors involved in the initial resuscitation of the multiply injured patient, such as altered level of consciousness, hemodynamic instability, or inexperience and diagnostic oversight, may lead to missed injuries. Injuries may be missed at any stage of the management of the trauma patient, including intraoperatively, and may involve all regions of the body. Established protocols in the initial management of the multiply injured patient, such as the primary and secondary surveys of the Advanced Trauma Life Support Course, will minimize the chance of missing immediately life-threatening injuries in the emergency department. A careful intraoperative approach must be used in all patients, but especially in those with hemodynamic instability, so that all areas are examined for possible injury, rather than concentrating simply on what is known to be injured. Use of the tertiary survey, a careful re-examination of the multiply injured trauma patient, especially when he or she awakes, will help detect injuries missed during the initial evaluation. Injuries will be missed. Rather than dismissing these as occurrences that happen only to the inexperienced or incompetent, one should approach the multiply injured trauma patient with both special alertness and the humility necessary to search for diagnostic oversights. This approach will lead to early discovery of missed injuries and will minimize the consequences.

Background Neutrophil apoptosis is an important physiological process in the resolution of pulmonary inflammation. Previous studies have shown that eicosapentaenoic acid (EPA; 20:5n-3) increases the rate of apoptosis in a concentration- and time-dependent manner in HL-60 cells. However, it is not known if the EPA-induced apoptosis involves the lipoxygenase (LO) and cyclooxygenase (COX) enzymes or the downstream metabolic products of these enzymes. Thus, the objective of this study was to determine the effects of inhibitors LO and COX enzymes on apoptosis, viability, and necrosis in EPA-treated HL-60 cells. Materials and methods Cells were incubated with 50 μ m EPA in the presence of an enzyme inhibitor (1–10 μ m ) for 12 h. Compounds were used to inhibit COX 1 and 2 (ibuprofen), 5-, 12-, 15-LO (NDGA), 12-LO (baicalein), 5-LO (AA-861), and 5-LO activating protein (MK-886). Eicosanoid (0.001–1.0 μ m ) add-back experiments were also conducted; LTB 4 and 5-HETE with 5-LO inhibition and 12-HETE with 12-LO inhibition. Flow cytometry was used to assess apoptosis. Results Inhibition of COX 1 and 2 had no effect on apoptosis. Inhibition of 5-LO and 12-LO significantly increased apoptosis in EPA-treated HL-60 cells. Addition of LTB 4 reduced apoptosis to levels significantly lower than in HL-60 cells treated with EPA alone; 5-HETE and 12-HETE also lowered apoptosis to control levels. Conclusions These data indicate that inhibition of LO, particularly 5-LO, increased apoptosis in EPA-treated HL-60 cells. Furthermore, this study demonstrated that the products of the LO enzymes, particularly LTB 4 , are critical in the regulation of apoptosis in EPA-treated HL-60 cells.

Background: The purpose of this study was to examine the contribution of age and gender to outcome after treatment of blunt splenic injury in adults. Methods: Through the Multi-Institutional Trials Committee of the Eastern Association for the Surgery of Trauma (EAST), 1488 adult patients from 27 trauma centers who suffered blunt splenic injury in 1997 were examined retrospectively. Results: Fifteen percent of patients were 55 years of age or older. A similar proportion of patients ≥ 55 went directly to the operating room compared with patients < 55 (41% vs. 38%) but the mortality for patients ≥ 55 was significantly greater than patients < 55 (43% vs. 23%). Patients ≥ 55 failed nonoperative management (NOM) more frequently than patients < 55 (19% vs. 10%) and had increased mortality for both successful NOM (8% vs. 4%, p < 0.05) and failed NOM (29% vs. 12%, p = 0.054). There were no differences in immediate operative treatment, successful NOM, and failed NOM between men and women. However, women ≥ 55 failed NOM more frequently than women < 55 (20% vs. 7%) and this was associated with increased mortality (36% vs. 5%) (both p < 0.05). Conclusion: Patients ≥ 55 had a greater mortality for all forms of treatment of their blunt splenic injury and failed NOM more frequently than patients < 55. Women ≥ 55 had significantly greater mortality and failure of NOM than women < 55.

The purpose of this study was to define the period of time after which delays in management incurred by investigations cause increased morbidity and mortality. The outcome study is intended to correlate time with death from esophageal causes, overall complications, esophageal related complications, and surgical intensive care unit length of stay.This was a retrospective multicenter study involving 34 trauma centers in the United States, under the auspices of the American Association for the Surgery of Trauma Multi-institutional Trials Committee over a span of 10.5 years. Patients surviving to reach the operating room (OR) were divided into two groups: those that underwent diagnostic studies to identify their injuries (preoperative evaluation group) and those that went immediately to the OR (no preoperative evaluation group). Statistical methods included Fisher's exact test, Student's T test, and logistic regression analysis.The study involved 405 patients: 355 male patients (86.5%) and 50 female patients (13.5%). The mean Revised Trauma Score was 6.3, the mean Injury Severity Score was 28, and the mean time interval to the OR was 6.5 hours. There were associated injuries in 356 patients (88%), and an overall complication rate of 53.5%. Overall mortality was 78 of 405 (19%). Three hundred forty-six patients survived to reach the OR: 171 in the preoperative evaluation group and 175 in the no preoperative evaluation group. No statistically significant differences were noted in the two groups in the following parameters: number of patients, age, Injury Severity Score, admission blood pressure, anatomic location of injury (cervical or thoracic), surgical management (primary repair, resection and anastomosis, resection and diversion, flaps), number of associated injuries, and mortality. Average length of time to the OR was 13 hours in the preoperative evaluation group versus 1 hour in the no preoperative evaluation group (p0.001). Overall complications occurred in 134 in the preoperative evaluation group versus 87 in the no preoperative evaluation group (p0.001), and 74 (41%) esophageal related complications occurred in the preoperative evaluation group versus 32 (19%) in the no preoperative evaluation group (p = 0.003). Mean surgical intensive care unit length of stay was 11 days in the preoperative evaluation group versus 7 days in the no preoperative evaluation group (p = 0.012). Logistic regression analysis identified as independent risk factors for the development of esophageal related complications included time delays in preoperative evaluation (odds ratio, 3.13), American Association for the Surgery of Trauma Organ Injury Scale grade2 (odds ratio, 2.62), and resection and diversion (odds ratio, 4.47).Esophageal injuries carry a high morbidity and mortality. Increased esophageal related morbidity occurs with the diagnostic workup and its inherent delay in operative repair of these injuries. For centers practicing selective management of penetrating neck injuries and transmediastinal gunshot wounds, rapid diagnosis and definitive repair should be made a high priority.

Background: Efficacy of chest radiograph protocol after tube thoracostomy tube (CT) removal. Methods: Retrospective review (July of 1995 to July of 1996) of 141 patients with CT followed throughout their hospitalization. Excluded patients died (23 patients) or had thoracotomy (13 patients) before CT removal. Results: A total of 105 patients had 113 CT removed (mean age, 36.9 years; Injury Severity Score = 23.4; CT duration, 5.0 days). Protocol chest radiographs were performed on average at 7.9 and 22.1 hours. Recurrent pneumothorax (RHPTX = new interpleural air) occurring in 12 patients (11%) and persistent pneumothorax (PHPTX = same volume of interpleural air) occurring in 13 patients (12%) caused no clinical problems and were treated without tube replacement. Three patients had symptoms after removal; none had RHPTX. Two patients had clinical signs; one reaccumulated a hemothorax requiring CT replacement, the other improved without replacement. Conclusions: Clinically significant RHPTX/PHPTX after CT removal is infrequent. Signs not symptoms detect CT removal complications. At our institution, chest radiographs are obtained in a delayed manner from protocol and offer no benefit over clinical assessment.

We measured D-dimer and plasminogen activator inhibitor-1 (PAI-1) activity in 45 trauma patients to assess their efficacy in predicting the post-traumatic hemostatic perturbations. We found the correlation between D-dimer measured by Simpli Red test and ELISA to be highly significant (p=0.0001). The D-dimer ELISA indicated that the serial changes of D-dimer after trauma were variable. However, the increases of D-dimer were associated with clinical conditions of the patient, such as trauma surgery, infections, or thrombotic complications. A significant correlation was found for D-dimer levels measured by ELISA versus the injury severity score (ISS) in all the trauma patients on day 1 (p=0.0153) and on day 2 (p=0.0495). The PAI-1 activity was increased at admission and showed a progessive decline from day 2 onward, and the correlation for the daily decline of PAI-1 was highly significant (p=0.0001). The PAI-1 activity and plasminogen activator activity showed a significant negative correlation on days 1, 2, and 3. PAI-1 activity correlated moderately with D-dimer level only on day 1 (p=0.0569). Three out of forty-five patients developed thrombotic complications: one patient who died from pulmonary embolism and two patients who developed adult respiratory distress syndrome (ARDS). In summary: 1) PAI-1 activity and D-dimer exhibited contrasting serial changes after trauma. 2) There was also a negative correlation between PAI-1 activity and PA activity. 3) A significant correlation of D-dimer with ISS confirms, as might be anticipated, that there is increased activation of the coagulation mechanism in severe injury, and suggests that D-dimer levels may prove useful to screen for patients at strong risks of thrombotic complications.

Background: Blunt aortic injury is a major cause of death from blunt trauma. Evolution of diagnostic techniques and methods of operative repair have altered the management and posed new questions in recent years. Methods: This study was a prospectively conducted multicenter trial involving 50 trauma centers in North America under the direction of the Multi-institutional Trial Committee of the American Association for the Surgery of Trauma. Results: There were 274 blunt aortic injury cases studied over 2.5 years, of which 81% were caused by automobile crashes. Chest computed tomography and transesophageal echocardiography were applied in 88 and 30 cases, respectively, and were 75 and 80% diagnostic, respectively. Two hundred seven stable patients underwent planned thoracotomy and repair. Clamp and sew technique was used in 73 (35%) and bypass techniques in 134 (65%). Overall mortality was 31%, with 63% of deaths being attributable to aortic rupture; mortality was not affected by method of repair. Paraplegia occurred postoperatively in 8.7%. Logistic regression analysis demonstrated clamp and sew (p = 0.002) and aortic cross clamp time of 30 minutes (p = 0.01) to be associated with development of postoperative paraplegia. Conclusions: Rupture after hospital admission remains a major problem. Although newer diagnostic techniques are being applied, at this time aortography remains the diagnostic standard. Aortic cross clamp time beyond 30 minutes was associated with paraplegia; bypass techniques, which provide distal aortic perfusion, produced significantly lower paraplegia rates than the clamp and sew approach.

Objective: To determine if cytokine responses and lung injury induced by intravenous (iv) lipopolysaccharide (LPS) at 4 hr were enhanced in rats that had been previously subjected to 30 min of total liver ischemia (Pringle's maneuver) followed by 24 hr or 3 days of reperfusion. Background: Many patients with liver trauma require occlusion of hepatic blood flow to control hemorrhage and facilitate repair. A significant number of these patients subsequently develop the systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction (MOD) characterized by the release of cytokines and tissue neutrophil influx. Macrophages, including Kupffer cells, may be activated by ischemic injury and dysregulation of their response to LPS may contribute to the development of SIRS and acute respiratory distress syndrome. Methods: Adult male Sprague–Dawley rats were randomly divided into six groups: three groups received total hepatic ischemia for 30 min and three groups had a sham procedure. Twenty-four hours or 3 days after hepatic ischemia/reperfusion injury, rats were treated with LPS (5 mg/kg) or saline and monitored for 4 hr. We collected serum, bronchoalveolar lavage (BAL) fluid, and lung tissue. Results: Serum and BAL cytokine concentrations were significantly increased by iv LPS; however, hepatic ischemia/reperfusion injury 24 hr or 3 days before iv LPS ameliorated this cytokine response. The LPS-induced pulmonary neutrophil influx and histopathological changes were similar in sham and hepatic ischemia/reperfusion-injured groups. Conclusions: Hepatic ischemia/reperfusion injury significantly attenuated the serum and BAL cytokine concentrations, but did not change pulmonary neutrophil influx or histopathological alterations in response to iv LPS.

We have shown that an enteral nutrition formula containing eicosa-pentaenoic acid (20:5n-3; EPA) provided beneficial antiinflammatory effects in critically ill patients with acute lung injury. The use of diets enriched with stearidonic acid (18:4n-3; SDA) may provide a novel means to increase EPA content in tissue phospholipids and to provide the health benefits typically associated with n-3 fatty acids from fish oil. There is little known about the effects of increased consumption of SDA on tissue phospholipid fatty acid composition. We examined whether diets supplemented with SDA can be used as a precursor to increase EPA content in liver phospholipids and to determine the effectiveness of SDA in increasing tissue EPA content as compared with dietary EPA in rats. Male Long--Evans rats ( n = 10) were randomly divided into three dietary groups and fed a modified US-17 diet providing 200 kcal/kg/day and containing either 2% oleic acid (OA, 18:1 n-9) ( n = 4), 1% EPA /1% OA ( n = 3), or 1% SDA/1% OA ( n = 3) for 2 weeks. Dietary fatty acid composition was controlled by substituting the ethyl esters of EPA and SDA for OA; thus changes in phospholipid fatty acid composition would be the result of dietary changes of these fatty acids. The fatty acid compositions (mol %) of liver phospholipids were determined by gas chromatography. There was a small reduction, although not significant, in AA content with EPA and SDA as compared with OA. SDA resulted in an increase in EPA content in liver phospholipids that was approximately 50% of that for EPA. There was a smaller increase in tissue DPA content with SDA than EPA as compared with OA. There was no significant increase in DHA content with either EPA or SDA as compared with OA. These results indicate that dietary SDA can be used to increase EPA content in liver phospholipids and the relative effectiveness of SDA conversion to EPA and incorporation into tissue phospholipids was equivalent to one-half of dietary EPA. TABLE—ABSTRACT P77 . Fatty acid OA EPA SDA 20:4 n-6 (AA) 28.3 ± 1.02 a 25.1 ± 0.42 a 26.6 ± 0.30 a 20:5 n-3 (EPA) 0.02 ± 0.06 a 1.21 ± 0.43 b 0.66 ± 0.04 a,b 22:5 n-3 (DPA) 0.16 ± 0.04 a 1.65 ± 0.33 b 1.01 ± 0.04 c 22:6 n-3 (DHA) 6.49 ± 0.26 a 6.39 ± 0.004 a 6.67 ± 0.43 a Note. Values with different superscripts are significantly different ( P ≤ 0.05).

Hospital-based helicopter services from a German (GER) and an American (AMR) university-affiliated trauma center were reviewed. All patients with multiple injuries transported via helicopter from the scene to the trauma centers during a 1-year period were included. The patients were comparable regarding mechanism of injury, age, flight times, mean ISS, ISS distribution, and number of severe injuries per body region (patients with AIS score > 3 for head, thorax, and abdomen). Overall mortality was 21 of 221 (9.5%) for GER and 21 of 186 (11.3%) for AMR (NS). Survivor-based TRISS analysis yielded Z statistics of +2.459 for GER (p < 0.025) and +1.049 for AMR (NS). M statistics were 0.89 for GER, 0.874 for AMR; the W statistic +1.35 for GER. There were nine unexpected survivors (Ps < 0.50) for GER and six for AMR. There was a significantly higher (p < 0.01) number of early deaths (< 6 hours) in AMR (12; ISS = 56) than in GER (four; ISS = 64). Analysis of the prehospital data demonstrated significant differences in the mean volume of IV fluids infused: 1800 mL, GER; 825 mL, AMR (p < 0.05); rate of intubation: 82 of 221 (37.1%) GER; 24 of 186 (13.4%) AMR (p < 0.001); and thoracic decompressions: 20 of 221 (9.1%) GER; 1 of 186 (0.5%) AMR (p < 0.001). Prehospital care in the GER system is directed on scene by a trauma surgeon member of the flight crew compared with a nurse/paramedic team with remote medical control in the AMR system.(ABSTRACT TRUNCATED AT 250 WORDS)

Pathologic thrombosis, in the form of pulmonary embolism (PE) and deep venous thrombosis (DVT), causes significant morbidity and mortality in trauma patients and presents a diagnostic and therapeutic challenge because of associated conditions in these patients. This study examines the measurement of D-dimer crosslinked fibrin degradation products (D-dimer XDPs) as an indicator of hypercoagulability that places a trauma patient at risk of developing pathologic thrombosis. The time course of changes in D-dimer values after trauma normally involves an initial increase with a rapid decrease of D-dimer XDP levels to normal. Patients who then demonstrate a second rise in D-dimer values are at risk for pathologic thrombosis. Forty-one trauma patients were studied, in two groups, to evaluate the potential use of D-dimer XDP levels in evaluating the risk of pathologic thrombosis. A secondary increase in D-dimer XDP levels was found to occur in patients with PE, although sepsis and adult respiratory distress syndrome can also cause a late increase. However, D-dimer determinations appear to provide an easy, relatively inexpensive means of evaluating trauma patients for the risk of pathologic thrombosis.

Changes in the fibrinolytic system may lead to coagulation disorders in acute trauma patients. This study examined fibrin degradation by measuring D-dimer crosslinked fibrin degradation products (indicates hypercoagulability), plasminogen activators (fibrinolysis), and antithrombin III in 42 adult trauma patients and correlated these data with injury severity, types of injury, complications, and clinical tests of coagulation. Hypercoagulability and suppression of fibrinolysis were seen in most patients and were not correlated with severity of injury. These changes appeared most severe in patients with nervous system injury. Several patients with less severe injuries but evidence of hypercoagulability developed clinical evidence of pathologic thrombosis. Latex agglutination of D-dimer provides a rapid test of fibrinolysis that may be clinically useful in the management of trauma patients who cannot be easily studied for thrombosis.

Severity of injury, patient age and preexisting medical conditions, time from injury to treatment, and quality of care rendered are generally recognized as major determinants of outcome after trauma. In a retrospective review, we compared 456 elderly patients (age greater than or equal to 65 years) with traumatic injuries to 985 younger patients (age less than 65). We compared cause of injury, injury severity score (ISS), seven risk factors indicating preexisting disease, complications, length of stay, and mortality. Overall mortality was 6.0% for patients aged less than 65 years and 8.6% for those older than 65. The injury severity score at which the probability of death was 10% was 17.3 in the older group and 24.9 in the younger group. Factors associated with outcome included cause of trauma (P less than .001), ISS (P less than .001), and number of complication factors (P less than .01). Preexisting risk factors were not significantly associated with outcome. We conclude that trauma in the elderly causes higher mortality with less severe injury, and that the mortality is related to the cause and severity of the trauma and the number of complications, and not to pre-existing disease. Length of stay increases with the severity of injury, except in the severely injured, who die.

We measured D-dimer and plasminogen activator inhibitor-1 (PAI-1) activity in 45 trauma patients to assess their efficacy in predicting the post-traumatic hemostatic perturbations. We found the correlation between D-dimer measured by Simpli Red test and ELISA to be highly significant (p=0.0001). The D-dimer ELISA indicated that the serial changes of D-dimer after trauma were variable. However, the increases of D-dimer were associated with clinical conditions of the patient, such as trauma surgery, infections, or thrombotic complications. A significant correlation was found for D-dimer levels measured by ELISA versus the injury severity score (ISS) in all the trauma patients on day 1 (p=0.0153) and on day 2 (p=0.0495). The PAI-1 activity was increased at admission and showed a progessive decline from day 2 onward, and the correlation for the daily decline of PAI-1 was highly significant (p=0.0001). The PAI-1 activity and plasminogen activator activity showed a significant negative correlation on days 1, 2, and 3. PAI-1 activity correlated moderately with D-dimer level only on day 1 (p=0.0569). Three out of forty-five patients developed thrombotic complications: one patient who died from pulmonary embolism and two patients who developed adult respiratory distress syndrome (ARDS). In summary: 1) PAI-1 activity and D-dimer exhibited contrasting serial changes after trauma. 2) There was also a negative correlation between PAI-1 activity and PA activity. 3) A significant correlation of D-dimer with ISS confirms, as might be anticipated, that there is increased activation of the coagulation mechanism in severe injury, and suggests that D-dimer levels may prove useful to screen for patients at strong risks of thrombotic complications.

Occult pneumothorax is defined as a pneumothorax that is detected by abdominal computed tomographic (CT) scanning, but not routine supine screening chest roentgenograms. Forty trauma patients with occult pneumothorax were prospectively randomized to management with tube thoracostomy (n = 19) or observation (n = 21) without regard to the possible need for positive pressure ventilation, to test the hypothesis that tube thoracostomy is unnecessary in this entity. Eight of the 21 patients observed had progression of their pneumothoraces on positive pressure ventilation, with three developing tension pneumothorax. None of the patients with tube thoracostomy suffered major complications as a result of the procedure. Hospital and ICU lengths of stay were not increased by tube thoracostomy. Patients with occult pneumothorax who require positive pressure ventilation should undergo tube thoracostomy.

This study examined a mesh wrap technique that provides effective hepatic tamponade and clinical experience with the technique in 6 patients is reported. Technical feasibility and effectiveness were investigated in 8 miniature swine. The animals were divided into two groups: group A (n = 4), control animals; stellate liver lacerations without mesh wrap or other measures for hemostasis, and group B (n = 4); stellate liver laceration with synthetic absorbable mesh wrap applied for hepatic hemostasis. Except for mesh application, all variables were held constant for both groups. All animals in the control group died within 20 to 120 minutes (mean: 65 minutes). All animals in group B survived (p = 0.029). The livers were harvested for gross and microscopic examinations. No abscess, bile leak, or hematoma was noted. Clinically, total mesh wrapping was attempted in 6 patients with blunt exsanguinating liver injuries. The technique failed intraoperatively in two patients with juxtacaval lacerations and hepatic vein avulsion injuries. One patient with a bilobar gunshot wound died later of sepsis. In three patients with bursting injuries, the technique successfully controlled bleeding and resulted in long-term survival. In conclusion, the total hepatic mesh wrap (1) is geometrically, technically, and mechanically feasible, (2) was not associated with complications in this series, and (3) can effectively secure hemostasis following parenchymal liver injury.

The thermal-dye indicator dilution technique of measuring extravascular lung water (EVLW- TD ) correlates well with gravimetric measurement of lung water (EVLW- GR ) when no positive-end expiratory pressure (PEEP) is used in both normal and edematous lungs. PEEP is often used to raise arterial oxygen tension in acute respiratory failure. This study was designed to answer the question: Does PEEP have an effect on the accuracy of the EVLW measurement by thermal dye? Sixteen mongrel dogs were anesthetized and intubated. Arterial and PA catheters were placed. They were divided into three groups and ventilated at PEEP levels of 5, 10, or 15 cm H 2 O. Fluids were given to minimize decrease in cardiac output with institution of PEEP. They were maintained for 5 hr with measurement of vital signs made hourly and measurement of blood gases and EVLW-TD made at baseline, 1, 3, and 5 hr. After final measurements, gravimetric determination of EVLW was done. Correlation between EVLW TD and EVLW GR remained good when low levels of PEEP were used. At 5 cm H 2 O PEEP, EVLW TD was 7.5 ± 0.9 and EVLW GR was 5.4 ± .3. At 10 cm H 2 O PEEP, they were 10.0 ± 0.9 and 6.5 ± 0.3. The correlations were 0.87 and 0.97, respectively. However, at 15 cm H 2 O PEEP, EVLW TD was 11.4 ± 1.3 and EVLW GR was 7.5 ± 0.6, with a correlation of only 0.59. The correlation between the two techniques seems to break down with higher levels of PEEP in dogs with normal lungs.

INTRODUCTION Pulmonary edema, or increased lung water, adversely affects gas exchange and pulmonary compliance. Numerous safety factors exist to protect against pulmonary edema and alveolar flooding. The most important of these safety factors is thought to be the lymphatic system, which removes water and protein that filters out of the pulmonary capillaries into the interstitium of the lung [ 131. Controversy has existed with regard to how lymph is propelled through the lymphatic system and cleared from the lungs. Essentially, the question centers on whether extrinsic forces caused by movement of surrounding structures (such as muscles, arteries, heart, or lungs) propels the lymph or whether intrinsic forces (rhythmic contractions of smooth muscle in the lymph vessels) were involved. Hall et al. cannulated lymph vessels throughout the body and discovered that extrinsic forces were minor and superimposed on the major intrinsic pressure waves. This applied everywhere except in the central lymphatic system, where the pressures generated by lung expansion and contraction seemed to be the major force [4]. Respiratory movement has been felt by many to be of primary importance for pulmonary or central lymph flow [7, 11, 12, 151. However, Staub and others have felt that intrinsic forces are the most important [ 12, 141. A relatively recent ventilatory technique, high frequency ventilation (HFV), offers an opportunity to examine the importance of extrinsic respiratory tidal motion on the propulsion of lymph in the pulmonary system [2,3]. High frequency ventilation differs from conventional ventilation by using a much smaller tidal volume (often less than dead space) and higher frequencies. This technique involves minimal bulk flow of air and almost no chest wall motion. High frequency ventilation provides a way to maintain normal blood gases for extended periods of time, while maintaining a decreased or absent tidal movement. We asked the question, does marked reduction of tidal expansion and contraction of the lungs have an effect on the accumulation of EVLW in normal dogs over 48 hr?

High-frequency ventilators (HFV) use increased respiratory rates and decreased tidal volumes to achieve gas exchange similar to conventional mechanical ventilators (CMV). This reverses the relative importance of convection and diffusion to gas exchange. There are currently 3 major types of HFV. They differ from each other in how gas is delivered, how they work, and what physiological effects they have. Conclusions drawn using one type of HFV cannot necessarily be applied to the others. This review examines the different types of HFV as well as the studies that have been conducted using HFV. It stresses the role that HFV may play in the surgical intensive care unit. The one certain indication presently for HFV is in patients with a bronchopleural fistula. It may also be useful as an adjunct to endoscopy and in adult respiratory distress syndrome (ARDS). If the underlying lung disease cannot be reversed (i.e., end-stage fibrotic ARDS), HFV has little to offer.

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.