Value of thoracic computed tomography in the first assessment of severely injured patients with blunt chest trauma: results of a prospective study

OBJECTIVE: The aim of this prospective study was to evaluate whether early thoracic computed tomography (TCT) is superior to routine chest x-ray (CXR) in the diagnostic work-up of blunt thoracic trauma and whether the additional information influences subsequent therapeutic decisions on the early management of severely injured patients. PATIENTS AND METHODS: In a prospective study of 103 consecutive patients with clinical or radiologic signs of chest trauma (94 multiple injured patients with chest trauma, nine patients with isolated chest trauma), an average Injury Severity Score of 30 and an average Abbreviated Injury Scale thorax score of 3, initial CXR and TCT were compared after initial assessment in our emergency department of a Level I trauma center. RESULTS: In 67 patients (65%) TCT detected major chest trauma complications that have been missed on CXR (lung contusion (n = 33), pneumothorax (n = 27), residual pneumothorax after chest tube placement (n = 7), hemothorax (n = 21), displaced chest tube (n = 5), diaphragmatic rupture (n = 2), myocardial rupture (n = 1)). In 11 patients only minor additional pathologic findings (dystelectasis, small pleural effusion) were visualized on TCT, and in 14 patients CXR and TCT showed the same pathologic results. Eleven patients underwent both CXR and TCT without pathologic fundings. The TCT scan was significantly more effective than routine CXR in detecting lung contusions (p < 0.001), pneumothorax (p < 0.005), and hemothorax (p < 0.05). In 42 patients (41%) the additional TCT findings resulted in a change of therapy: chest tube placement, chest tube correction of pneumothoraces or large hemothoraces (n = 31), change in mode of ventilation and respiratory care (n = 14), influence on the management of fracture stabilization (n = 12), laparotomy in cases of diaphragmatic lacerations (n = 2), bronchoscopy for atelectasis (n = 2), exclusion of aortic rupture (n = 2), endotracheal intubation (n = 1), and pericardiocentesis (n = 1). To evaluate the efficacy of all those therapeutic changes after TCT the rates of respiratory failure, adult respiratory distress syndrome, and mortality in the subgroup of patients with Abbreviated Injury Scale thorax score of > 2 were compared with a historical control group, consisting of 84 patients with multiple trauma and with blunt chest trauma Abbreviated Injury Scale thorax score of > 2, prospectively studied between 1986 and 1992. Age (38 vs. 39 years), average Injury Severity Score (33 vs. 38), and the rate of respiratory failure (36 vs. 56%) were not statistically different between the two groups, but the rates of adult respiratory distress syndrome (8 vs. 20%; p < 0.05) and mortality (10 vs. 21%; p < 0.05) were significantly reduced in the TCT group. CONCLUSIONS: TCT is highly sensitive in detecting thoracic injuries after blunt chest trauma and is superior to routine CXR in visualzing lung contusions, pneumothorax, and hemothorax. Early TCT influences therapeutic management in a significant number of patients. We therefore recommend TCT in the initial diagnostic work-up of patients with multiple injuries and with suspected chest trauma because early and exact diagnosis of all thoracic injuries along with sufficient therapeutic consequences may reduce complications and improve outcome of severely injured patients with blunt chest trauma.     

Differential performance of TRISS-like in early and late blunt trauma deaths

OBJECTIVES: (1) To independently validate the Trauma and Injury Severity Score-Like (TRISS-Like) model derived by Offner et al. (Revision of TRISS for intubated patients. J Trauma. 1992;32:32-35) in a population of Canadian blunt trauma victims, and (2) to compare the ability of this model to predict mortality in early and late trauma deaths. STUDY POPULATION: Prospective cohort of blunt trauma cases with Injury Severity Score > 12 identified from the Ontario Trauma Registry over a 5-year period. STUDY DESIGN: The TRISS-Like model consisting of age, Injury Severity Score, systolic blood pressure, and best motor response of the Glasgow Coma Scale was evaluated as to its ability to predict mortality by determining the sensitivity, specificity, and the area under the receiver operating characteristic curve. The sample was then divided into early (< or = 7 days) and late mortality subgroups in which model performance was evaluated with respect to time of death. RESULTS: A total of 7,703 patients were included in this analysis. The overall mortality was 12.3%. The TRISS-Like model allowed for assessment of an additional 23% of patients than would standard TRISS and performed with a sensitivity of 97.1%, specificity of 39.8% and an area under the receiver operating characteristic curve of 0.873. Analysis of mortality with respect to time demonstrated that 75% of deaths occurred by day 7. The specificity and receiver operating characteristic area increased in the early (< or = 7 days) subgroup, 46.5% and 0.935, respectively, compared with 20.8% and 0.778 in the late mortality group. CONCLUSIONS: TRISS-Like demonstrated similar performance to that reported with the standard TRISS model but with the additional advantage that it is more generalizable because it can be applied to intubated patients. TRISS-Like demonstrated substantially superior performance in early trauma deaths compared with those that occurred late. This differential performance may be because the model does not include risk factors for late mortality.     

A comparison of artificially-depleted, lyophilized coumarin and fresh coumarin plasmas in thromboplastin calibration. European Concerted Action on Anticoagulation

BACKGROUND/PURPOSE: Pediatric truncal vascular injuries are rare, but the reported mortality rate is high (35% to 55%), and similar to that in adults (50% to 65%). This report examines the demographics, mechanisms of injury, associated trauma, and results of treatment of pediatric patients with noniatrogenic truncal vascular injuries. METHODS: A retrospective review (1986 to 1996) of a pediatric (< or = 17 years old) trauma registry database was undertaken. Truncal vascular injuries included thoracic, abdominal, and neck wounds. RESULTS: Fifty-four truncal vascular injuries (28 abdominal, 15 thoracic, and 11 neck injuries) occurred in 37 patients (mean age, 14+/-3 years; range, 5 to 17 years); injury mechanism was penetrating in 65%. Concomitant injuries occurred with 100% of abdominal vascular injuries and multiple vascular injuries occurred in 47%. Except for aortic and one SMA injury requiring interposition grafts, these wounds were repaired primarily or by lateral venorrhaphy. Nonvascular complications occurred more frequently in patients with abdominal injuries who were hemodynamically unstable (systolic blood pressure [BPS] <90) on presentation (19 major complications in 11 patients versus one major complication in five patients). Thoracic injuries were primarily blunt rupture or penetrating injury to the thoracic aorta (nine patients). Thoracic aortic injuries were treated without bypass, using interposition grafts. In patients with thoracic aortic injuries, there were no instances of paraplegia related to spinal ischemia (clamp times, 24+/-4 min); paraplegia occurred in two patients with direct cord and aortic injuries. Concomitant injuries occurred with 83% of thoracic injuries and multiple vascular injuries occurred in 25%. All patients with thoracic vascular injuries presenting with BPS of less than 90 died (four patients), and all with BPS 90 or over survived (eight patients). There were 11 neck wounds in 9 patients requiring intervention, and 8 were penetrating. Overall survival was 81%; survival from abdominal vascular injuries was 94%, thoracic injuries 66%, and neck injuries 78%. CONCLUSIONS: Survival and subsequent complications are related primarily to hemodynamic status at the time of presentation, and not to body cavity or vessel injured. Primary anastomosis or repair is applicable to most nonaortic wounds. The mortality rate in pediatric abdominal vascular injuries may be lower than previously reported.     

Expression of inducible nitric oxide synthase in the brains of scrapie-infected mice

Thoracic trauma in the elderly population constitutes a major challenge for both thoracic and trauma surgeons as their presentation and outcomes differ from the adult population in addition to their high morbidity and mortality. One hundred and one patients, 60 years of age or older, with thoracic trauma were treated at Dicle University School of Medicine during a 6-year period. Eighty-five per cent were male and 15% were female with a mean age of 64.5 years. The cause of thoracic injury was blunt in 77.2% and penetrating in 22.8% of the patients. Sixty-two patients (61.4%) had isolated thoracic injuries. The median Injury Severity Score (ISS) was 23. The morbidity rate was 23.8%. The mortality rate was 16.8%. Seven of 10 patients (70%) who had an ISS greater than 25 died, whereas six of 24 (25%) patients with an ISS between 17 and 25, and four of 67 (5.9%) patients with an ISS less than 16 died. In the elderly the morbidity and mortality rates were higher for blunt trauma compared with penetrating trauma. For ISS greater than 25 the mortality rate was 71.4% for blunt and 66.6% for penetrating trauma. As the morbidity and mortality rate are significantly higher in the elderly patients the approach to these patients should include recognition of their high risk for morbidity and mortality, especially for those who had an ISS greater than 25.     

Quantification of traumatic hemomediastinum using transesophageal echocardiography: impact on patient management

STUDY OBJECTIVES: To determine whether the quantitative evaluation of hemomediastinum using transesophageal echocardiography (TEE) is predictive of the presence of a traumatic disruption of the thoracic aorta (TDA) or its branches in patients who have sustained severe blunt chest trauma. DESIGN: Retrospective study. SETTING: ICU of a tertiary referral teaching hospital. PATIENTS: Forty-one patients sustaining severe blunt chest trauma (32 men, nine women; mean age, 43+/-16 years; mean Injury Severity Score, 39+/-22) who underwent a TEE study were divided into two groups, patients with (group TDA+, n=15) or without (group TDA-, n=26) major vascular injury diagnosed using an alternative method such as aortography, surgery, or necropsy. The control group included 41 age- and sex-matched patients with an unremarkable TEE study performed to rule out an intracardiac source of emboli. INTERVENTIONS: The presence of hemomediastinum was quantitatively assessed by measuring the distances between the esophageal scope and anteromedial aortic wall (distance 1), and between the posterolateral aortic wall and left visceral pleura (distance 2) at the level of the aortic isthmus. An observer who was unaware of both medical history and final diagnosis measured the distances. MEASUREMENTS AND RESULTS: In group TDA+, TEE demonstrated aortic injuries in 13 patients, revealed an isolated hemomediastinum in one patient (ruptured intercostal arteries), and was unremarkable in the remaining patient, who sustained a disrupted right subclavian artery. No associated major vessel injuries were diagnosed in the group TDA- (normal aortograms). When compared to the control group, mean distances were greater in patients with chest trauma (distance 1=5.5+/-4.4 mm vs 2.7+/-0.8 mm, p=0.001; distance 2=3.8+/-5.0 mm vs 1.2+/-0.3 mm, p=0.02). The corresponding distances were even greater in group TDA+ when compared with group TDA- (distance 1=8.6+/-5.9 mm vs 3.7+/-1.5 mm, and distance 2=7.1+/-7.0 mm vs 2.0+/-1.7; for both differences, p<0.01). A threshold value of 5.5 mm for distance 1 or 6.6 mm for distance 2 had a sensitivity of 80%, a specificity of 92%, a positive and negative predictive value of 86% and 89%, respectively, for the diagnosis of underlying major vascular injury. CONCLUSIONS: TEE allows quantitative assessment of traumatic hemomediastinum. The presence of a large hemomediastinum requires further evaluation by aortography, even if the thoracic aorta appears normal during the TEE examination, in order to rule out an underlying major vascular injury which may be outside the field of view of the echocardiographer.     

Delayed surgical fixation of femur fractures is a risk factor for pulmonary failure independent of thoracic trauma

A recent retrospective analysis of femur fractures concluded that early surgical fixation in patients who have sustained blunt thoracic trauma (AIS score for Thorax > or = 2) was a risk factor for postoperative pulmonary failure. We conducted a review of all femur fractures admitted to a level I trauma center from November, 1988 to May, 1993. Inclusion criteria were ISS > or = 18, mid-shaft femur fractures treated with reamed intramedullary fixation, and no mortalities secondary to head trauma or hemorrhagic shock. One hundred thirty-eight patients met these criteria. Four patient groups were created: N1--no thoracic trauma (AIS score for thorax < 2), and early surgical fixation (< 24 hours after injury, n = 49); N2--no thoracic trauma and delayed fixation (> or = 24 hours, n = 8); T1--thoracic trauma (AIS score for Thorax > or = 2) and early fixation (n = 56); T2--thoracic trauma and delayed fixation (n = 25). There were no significant differences in age, Injury Severity Score, or Glasgow Coma Scale score between the four groups. Mortality rate, length of stay (LOS), LOS in the TICU, and duration of mechanical ventilation tended to be greater in patients with delayed fracture fixation, however, this was not statistically significant. The N2 patients had a pneumonia rate of 38% compared with 10% in group N1 (p = 0.07). The T2 patients had a pneumonia rate of 48% compared with 14% in group T1 (p = 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)     

Computed tomographic grading is useful in the selection of patients for nonoperative management of blunt injury to the spleen

Although nonoperative management of blunt splenic injury (NMBSI) has an established role in the overall management of adult patients with blunt splenic injury, the criteria by which patients are selected continue to be debated. The purpose of this study is to establish the effectiveness of a defined set of criteria that includes CT grading for the selection of patients for NMBSI by examining the outcomes of patients managed in this manner 1 year before with those 1 year after the implementation of this specific set of selection criteria. All patients hospitalized at St. Joseph Mercy Hospital over the time period April 1994 through July 1996 with blunt splenic injury were included. Patients who died in the Emergency Department were excluded. Patients admitted from April 1994 through April 1995 composed Group I, those treated before the specific selection criteria, whereas those admitted from July 1995 through July 1996 composed Group II, those treated after the implementation of selection criteria. The two groups were compared with respect to demographic parameters, Injury Severity Score, mechanism of injury and length of stay. Outcomes were compared between these two groups. Those patients successfully managed without operation were further compared with those for whom NMBSI was unsuccessful. A total of 57 patients met the criteria for study entry, 28 from Group I and 29 from Group II. There were no significant differences between these two groups with respect to age, sex, mechanism of injury, Injury Severity Score, or length of stay. Nine of 27 in Group I required immediate operation; 19 were initially managed nonoperatively. Four of 19 required delayed laparotomy for bleeding, and all required splenectomy. Between patients successfully managed nonoperatively and those requiring delayed operation, the only significant difference was CT grade (1.47 vs 3.5; P = 0.0001). In Group II, after the implementation of selection criteria that included CT grade, no patient required delayed operation. Eleven underwent immediate operation, whereas 18 were successfully managed nonoperatively. We conclude that, in the hemodynamically stable patient without clinical indication for laparotomy, CT grading of the splenic injury is a reliable criterion by which patients may be selected for nonoperative management.     

Malformations of neocortical development: magnetic resonance imaging correlates

BACKGROUND: The objective of this study was to assess the diagnostic and therapeutic effectiveness of videothoracoscopy in thoracic trauma patients. METHODS: The design was a retrospective review. The setting was a major trauma center at an urban county hospital. Forty-one hemodynamically stable patients sustaining thoracic trauma were reviewed (34 penetrating and 7 blunt injuries). In the acute setting (< 24 h), videothoracoscopy was used for continued bleeding(6) and suspected diaphragmatic injury(17). Thoracoscopy was used in delayed settings (> 24 h) for treatment of thoracic trauma complications(18) including clotted hemothorax(14), persistent air leak(1), widened mediastinum(1), and suspected diaphragmatic injury(2). RESULTS: The average Injury Severity Score (ISS) of these patients was 18.9 +/- 10.0. Three of 6 patients (50%) with continued bleeding were successfully treated thoracoscopically. Nine of 10 (90%) diaphragmatic injuries were confirmed by thoracoscopy, and 7 of these 9 patients (77%) were repaired thoracoscopically. Thirteen of 14 patients (93%) with clotted hemothoraces and one with a persistent air leak were treated successfully using thoracoscopy. An aortic injury was ruled out in one patient. CONCLUSIONS: Videothoracoscopy is a safe, accurate, minimally invasive, and potentially cost-effective method for the diagnosis and therapeutic management of thoracic trauma patients.     

The dissected aorta: percutaneous treatment of ischemic complications--principles and results

PURPOSE: Describe the principles and results of percutaneous treatment of ischemic complications of aortic dissection. MATERIALS AND METHODS: Twenty-four patients with aortic dissection complicated by ischemic compromise of the liver or bowel (n = 15), kidney (n = 18), or lower extremity (n = 13) were evaluated by means of aortography, intravascular ultrasound, and manometry, and were treated percutaneously. Visceral arteries were classified as obstructed or nonobstructed. Obstruction was classified as static, in which the dissecting hematoma extended into and narrowed the lumen of a branch artery, or dynamic, in which the dissection flap prolapsed into the vessel origin or narrowed the true lumen (TL) above it. Treatment consisted of vascular stents alone (n = 4), or balloon fenestration (n = 20) without (n = 8) or with (n = 12) vascular stents. RESULTS: Obstruction was present in 77 arteries and was static in 12 arteries, dynamic in 45 arteries, static and dynamic in 17 arteries, and indeterminate in three arteries. Percutaneous treatment did not alter false lumen (FL) pressure, but reduced the peak systolic interluminal pressure gradient from 28 mm Hg to 2 mm Hg and restored flow in 71 of 77 arteries (92%). Six patients died within 30 days (25% operative mortality), none as a result of the procedure. Two additional patients died in follow-up from complications of an expanding FL. Technical complications in two patients due to altered hemodynamics after initial intervention were recognized and corrected percutaneously during the same procedure. CONCLUSIONS: Percutaneous fenestration and endovascular stent deployment are indicated to restore blood flow to arteries compromised by aortic dissection. The prognosis of patients is related to the ischemic injury sustained prior to the percutaneous interventional procedure and, in patients with acute type I dissection who have not undergone surgery, to the preoperative stability of the FL.     

Solid viscus injury predicts major hollow viscus injury in blunt abdominal trauma

BACKGROUND: As nonoperative management of blunt abdominal trauma has become more popular, reliable models for predicting the likelihood of concomitant hollow viscus injury in the hemodynamically stable patient with a solid viscus injury are increasingly important. METHODS: The Pennsylvania Trauma Systems Foundation registry was reviewed for the period from January 1992 to December 1995 for all adult (age > 12 years) patients with blunt trauma and an Abbreviated Injury Scale (AIS) score > or = 2 for a solid viscus (kidney, liver, pancreas, spleen). Patients with an initial systolic blood pressure < 90 mm Hg were excluded. Hollow viscus injuries included only lacerations or perforations of the gallbladder, gastrointestinal tract, or urinary tract. RESULTS: In the 4-year period, 3,089 patients sustained solid viscus injuries, 296 of whom had a hollow viscus injury (9.6%). The mean age was 35.6 years, mean Injury Severity Score was 22.2, and mean Revised Trauma Score was 7.3; 63.3% of the patients were male. A solitary solid viscus injury occurred in 2,437 patients (79%), 177 of whom (7.3%) had a hollow viscus injury. The frequency of hollow viscus injury increased with the number of solid organs injured: 15.4% of patients with two solid viscus injuries (n = 547) and 34.4% of patients with three solid viscus injuries (n = 96) suffered a concomitant hollow viscus injury (p < 0.001 vs. one organ). A hollow viscus injury was 2.3 times more likely for two solid viscus injuries and 6.7 times more likely for three solid viscus injuries compared with a solitary solid viscus injury. For solitary solid viscus injury, the frequency of hollow viscus injury varied little with increasing AIS score (AIS score 2, 6.6%; AIS score 3, 8.2%; AIS score 4, 9.2%; AIS score 5, 6.2%) (p = 0.27 between groups), suggesting that the incidence of hollow viscus injury is related more to the number of solid visceral injuries than the severity of individual organ injury. Also, when the sum of the AIS scores for solid viscus injuries was <6, the mean rate of hollow viscus injury was 7.8%. This increased to 22.8% when the sum of the AIS scores for solid viscus injury was > or =6 (p < 0.001). A pancreatic injury in combination with any other solid viscus injury had a rate of hollow viscus injury of >33%. CONCLUSION: A model of organ injury scaling predicted hollow viscus injury. Multiple solid viscus injuries, particularly pancreatic, or abdominal solid viscus injuries with an AIS score > or = 6, were predictive of hollow viscus injury. Identification of these injury patterns should prompt consideration for early operative intervention.     

Blunt traumatic disruption of the thoracic aorta: a rare injury in children

Rupture of the thoracic aorta secondary to blunt chest trauma is an exceedingly uncommon injury in pediatric patients. We present a case of blunt traumatic aortic disruption in a 10-year-old child who was successfully managed by primary aortic repair using partial cardiopulmonary bypass. The epidemiology and pathophysiology of this injury, with particular reference to children, is reviewed. The ongoing controversies regarding the diagnosis and operative management of this injury are summarized.     

Trauma in pregnancy: the role of interpersonal violence

OBJECTIVE: Our purpose was to determine what role interpersonal violence as intentional injury plays in the pregnant trauma victim. STUDY DESIGN: We performed a retrospective review of medical records. RESULTS: During a 9-year period in a single university medical and trauma center, 203 pregnant women were treated for a physically traumatic event. Sixty-four women (31.5%) were victims of intentional injury, in most cases by the husband or boyfriend. Although the mean Injury Severity Score was higher in women with fetal death than in women with successful pregnancy outcomes (7.25 vs 1.74, respectively; p < 0.01), 5 of the 8 women with fetal losses incurred these despite an apparent absence of physical injury (maternal Injury Severity Score = 0). CONCLUSIONS: Interpersonal violence during pregnancy is a frequent and increasingly common cause of maternal injury. The inconsistent relationship between Injury Severity Score and serious fetal injury or death is underscored by the loss of 5 fetuses despite an Injury Severity Score of 0.     

Mortality and neurologic morbidity after repair of traumatic aortic disruption

BACKGROUND: Traumatic disruption of the thoracic aorta frequently results in death before operative repair. The determinants of mortality after repair, however, are uncertain. In addition, intraoperative strategies for reducing the incidence of spinal cord injury remain controversial. METHODS: The records of 45 consecutive patients undergoing repair of traumatic disruption of the thoracic aorta at a single institution during a 9-year period were reviewed in a retrospective fashion. Patient age ranged from 15 to 81 years (mean age, 33.9 years). Twenty-two patients (49%) had multiple associated injuries, and 8 (18%) had isolated aortic injuries. Nine patients (20%) experienced preoperative hypotension (systolic blood pressure of less than 90 mm Hg). Repair was performed with partial bypass in 22 patients, a heparinized shunt in 2, and no distal perfusion (clamp and sew technique) in 21. RESULTS: Nine patient (20%) died after operation. Multivariate logistic regression analysis of preoperative and intraoperative variables identified advancing age and preoperative hypotension as independent predictors of operative death. The presence of associated injuries was not an independent predictor of operative death. All 4 patients with injuries proximal to the aortic isthmus died. Ten patients were excluded from analysis of spinal cord injury either because of preoperative neurologic deficit or because of death before postoperative evaluation. Six (17%) of the remaining 35 patients had development of paraplegia: 5 of the 15 patients having the clamp and sew technique, 1 of the 2 with a shunt, and 0 of the 18 patients with bypass (p < 0.05, clamp and sew versus bypass). In the clamp and sew group, patients in whom paraplegia developed had significantly longer aortic clamp times than those without neurologic injury (40.6 +/- 4.4 minutes versus 28.7 +/- 2.9 minutes, respectively; p < 0.05). CONCLUSIONS: Advancing age, preoperative hypotension, and perhaps injury location are important determinants of death after repair of traumatic disruption of the thoracic aorta. Adjunctive perfusion with partial bypass should be used during repair to reduce the incidence of spinal cord injury.     

Popliteal artery trauma. Systemic anticoagulation and intraoperative thrombolysis improves limb salvage

OBJECTIVE: This study was conducted to evaluate those factors associated with popliteal artery injury that influence amputation, with emphasis placed on those that the surgeon can control. SUMMARY BACKGROUND DATA: Generally accepted factors impacting amputation after popliteal artery injury include blunt trauma, prolonged ischemic times, musculoskeletal injuries, and venous disruption. Amputation ultimately results from microvascular thrombosis and subsequent tissue necrosis, predisposed by the paucity of collaterals around the knee. METHODS: Patients with popliteal artery injuries over the 10-year period ending November 1995 were identified from the trauma registry. Preoperative (demographics, mechanism and severity of injury, vascular examination, ischemic times) and operative (methods of arterial repair, venous repair-ligation, anticoagulation-thrombolytic therapy, fasciotomy) variables were studied. Severity of extremity injury was quantitated by the Mangled Extremity Severity Score (MESS). Amputations were classified as primary (no attempt at vascular repair) or secondary (after vascular repair). After univariate analysis, logistic regression analysis was performed to identify the independent risk factors for limb loss. RESULTS: One hundred two patients were identified; 88 (86%) were males and 14 (14%) were females. Forty injuries resulted from blunt and 62 from penetrating trauma. There were 25 amputations (25%; 11 primary and 14 secondary). Patients with totally ischemic extremities (no palpable or Doppler pulse) more likely were to be amputated (31% vs. 13%; p < 0.04). All requiring primary amputations had severe soft tissue injury and three had posterior tibial nerve transection; the average MESS was 7.6. Logistic regression analysis identified independent factors associated with secondary amputation: blunt injury (p = 0.06), vein injury (p = 0.06), MESS (p = 0.0001), heparin-urokinase therapy (p = 0.05). There were no complications with either heparin or urokinase. CONCLUSIONS: Minimizing ischemia is an important factor in maximizing limb salvage. Severity of limb injury, as measured by the MESS, is highly predictive of amputation. Intraoperative use of systemic heparin or local urokinase or both was the only directly controllable factor associated with limb salvage. The authors recommend the use of these agents to maximize limb salvage in association with repair of popliteal artery injuries.     

Management of blunt liver trauma in children

INTRODUCTION: Management of liver trauma in childhood represents a rare but formidable challenge. METHODS: Clinical presentation, grade of liver injury and Injury Severity Score (ISS) were studied in 11 cases of blunt liver trauma to examine factors influencing outcome. RESULTS: Seven of the 11 children were injured severely and had an ISS greater than 16. Seven who were haemodynamically stable were treated without operation, but four required surgery for grade III, IV and V liver injuries. Two children had primary repair of hepatic lacerations. Perihepatic packing was employed in two other cases (grade IV and V injury) for uncontrollable haemorrhage. Delayed debridement and thrombectomy plus vena cava repair with suturing of liver lacerations in these patients obviated heroic efforts at primary repair. Nine children survived. There were two deaths from head and neck trauma. DISCUSSION: Selected children with liver trauma can be managed non-operatively using established trauma guidelines. Perihepatic packing is recommended in unstable patients with complex injuries, followed by delayed definitive repair.     

Reoperations after operation on the thoracic aorta: etiology, surgical techniques, and prevention

Recurrent aortic aneurysms, persistent or new dissection, new onset of valvular and coronary artery disease, graft infection, and prosthetic endocarditis are not rare after thoracic aortic operations; they can be difficult to diagnose and represent a formidable surgical challenge. Between 1977 and 1991, 876 operations were performed on the thoracic aorta in our institution: 340 in dissections, 299 in true aneurysms, 150 for aortic remodeling and external wall support during aortic valve replacement, and 87 for miscellaneous causes. During the same period, there were 193 additional reoperations. Vascular reoperations on abdominal aorta and peripheral arteries accounted for 73 cases and are not further discussed in this study. The reasons for reoperation (n = 130) in 120 patients were: failure of biologic valves (n = 23); aneurysm recurrence in a proximal or distal aortic segment (n = 21); pseudoaneurysm formation at suture lines (n = 13); new dissection or dilatation involving ascending aorta (n = 11), aortic arch (n = 13), and descending aorta (n = 10); aneurysm after aortic remodeling (n = 13); new onset of valvular disease (n = 5); and new onset of coronary disease (n = 5). Infected aortic graft and prosthetic endocarditis accounted for 10 reoperations, and a planned two-staged procedure was performed in 6 patients. Omitting the failed biologic valves, reoperations were performed on the aortic segment previously operated on in 69.3% of the cases and on other thoracic segments in 30.7%. Overall hospital mortality rate after reoperation was 5.8%. A significant decrease in operative mortality was observed in the most recent period (3.0% between 1989 and 1991). Reoperations are technically demanding, and some of them are preventable; therefore (1) graft inclusion technique should be abandoned in ascending aortic operation due to formation of false aneurysms; (2) in patients with Marfan syndrome, complete repair of the diseased aorta should be attempted during the initial operation; (3) aortic arch dissection should be repaired definitively during the first operation in low-risk patients; (4) biological valves should be avoided in aneurysm operations; and (5) homograft replacement is the treatment of choice in prosthetic endocarditis or in infected composite graft after an aortic valve or ascending aortic operation.     

Avoiding false positives in colony PCR

BACKGROUND: The Injury Severity Score (ISS) does not take into account multiple injuries in the same body region, whereas a New ISS (NISS) may provide a more accurate measure of trauma severity by considering the patient's three greatest injuries regardless of body region. The purpose of this study was to evaluate the ISS and NISS in patients with blunt trauma. METHODS: Consecutive individuals treated from January of 1992 to September of 1996 at one institution were included if they had sustained blunt trauma and satisfied triage standards (n = 2,328). For each patient, we computed the ISS and the NISS to determine how often the two scores were identical or discrepant. Discrepant cases were then further analyzed using receiver operating characteristic curves to determine which score better predicted short-term mortality. RESULTS: The mean ISS was 25 +/- 13, and the mean NISS was 33 +/- 18. The two predictive scores were identical in 32% of patients and discrepant in 68% of patients. Patients with identical scores had a lower mortality rate than patients with discrepant scores (10% vs. 13%; p < 0.02). In patients with discrepant scores, the area under the receiver operating characteristic curves was greater for the NISS than the ISS (0.852 vs. 0.799; p < 0.001), and greater amounts of discrepancy were associated with increasing rates of mortality (p < 0.001). CONCLUSIONS: The NISS often increases the apparent severity of injury and provides a more accurate prediction of short-term mortality. The benefit associated with using the NISS rather than the ISS must be weighed against the disadvantages of changing a scoring system and the potential for still greater improvements.     

Bioavailability of iron in cottonseed meal, ferric sulfate, and two ferrous sulfate by-products of the galvanizing industry

BACKGROUND: The aim of this study was to compare the outcome of severe blunt trauma in children receiving prehospital care from either physician-staffed advanced life support (ALS) units, or from basic life support (BLS) units staffed by emergency medical technicians. METHODS: The records of 288 children with severe blunt trauma who required intensive care in the regional level 1 trauma center or who died from their injuries were analyzed retrospectively. Patients were excluded if resuscitation at the scene was not attempted, if the level of prehospital care was unspecified, or if arrival at the level 1 trauma center was delayed beyond 150 minutes. Seventy-two patients met the inclusion criteria of BLS-, and 49 the criteria of ALS-prehospital care. RESULTS: A reduced mortality rate (22.4% v 31.9%) was seen in the ALS group, which was more apparent in a "salvageable but high-risk" subgroup, characterized by Glasgow Coma of Scale 4 through 8, Pediatric Trauma Score of 0 through 5, and Injury Severity Score (ISS) of 25 through 49. However, a statistically significant difference was only seen when trauma severity was evaluated by the ISS. CONCLUSION: An improved outcome in children with severe blunt trauma has been demonstrated when prehospital care is provided by physician-staffed ALS units compared with BLS units.     

Preferential benefit of implementation of a statewide trauma system in one of two adjacent states

BACKGROUND: Implementation of Oregon's trauma system was associated with a reduction in the risk of death for hospitalized injured patients. An alternative explanation for improved outcome, however, is favorable concurrent temporal trends, e.g., new technologies and treatments. PATIENTS AND METHODS: To control for temporal trends, seriously injured hospitalized patients in Oregon and Washington were compared before either state had a trauma system (1985-1988) and when only the Oregon trauma system had been implemented (1990-1993). The study group consisted of hospitalized injured patients aged 16 to 79 years with one or more index injuries in six body regions, i.e., head, chest, spleen/liver, femur or pelvis fracture, and burns. Hospital discharge claims data were analyzed, converting International Classification of Diseases, Ninth Revision, Clinical Modification, discharge diagnosis codes to Abbreviated Injury Scale scores and Injury Severity Scores using a conversion algorithm. Multivariate logistic regression models were used to estimate the differential risk-adjusted odds of death in Oregon compared with Washington after adjustment for demographics, injury type, and injury severity. RESULTS: Findings indicated no difference in the risk-adjusted odds of death between Oregon and Washington while both states functioned under an ad hoc trauma system (1985-1988). A significant reduction in the risk of death, however, was noted in Oregon for patients with an index injury and an Injury Severity Score > 15 compared with Washington (adjusted odds ratio (OR) = 0.80, 95% confidence interval (CI) = 0.70-0.91) after trauma system implementation in Oregon (1990-1993). Specifically, reductions in the risk of death were demonstrated for patients with head injuries (adjusted OR = 0.70, 95% CI = 0.59-0.82) or liver/spleen injuries (adjusted OR = 0.73, 95% CI = 0.54-0.99). CONCLUSION: Assuming that the two states demonstrated similar concurrent temporal trends, the findings support the conclusion that improved outcomes among injured patients in Oregon may be attributed to the institution of a statewide trauma system.     

Review of liver trauma management in Tasmania: an analysis of risk factors for mortality and morbidity

A review of liver trauma treated by the major trauma care facilities of Tasmania in the 5 year period between 1989 and 1993 is presented. The aim of this retrospective review was to provide an audit of the management of liver trauma in the island of Tasmania and to analyse the risk factors contributing to mortality and major morbidity. Thirty-seven patients were treated with a median Injury Severity Score (ISS) of 14 (range 9-34). The overall mortality rate of this series was 5.8%. Age, mechanism of injury (blunt or penetrating), delay prior to hospital presentation and modality of treatment (operative or non-operative) were not significant risk factors for mortality and morbidity; however, transfusion requirement of over 10 units of blood (P < 0.005), ISS score of over 20 (P < 0.0005), haemodynamic instability at presentation (P < 0.05) and a Hepatic Injury Score (HIS) grade of 3 or more (P < 0.05) were statistically significant risk factors.