US in blunt abdominal trauma: need to be there 24 hours a day!

Purpose: To evaluate the utility of routine abdominal ultrasound (US) as first diagnostic imaging method 24 h a day in a series of patients admitted with blunt abdominal trauma to our level II trauma center. Methods: Two thousand four hundred and eleven consecutive patients admitted after blunt abdominal trauma over 12 months were prospectively evaluated using abdominal US. The examinations were performed within 25 min after admission. An experienced senior radiologist was available on site 24 h a day (including holidays) to perform all the US examinations. The US examination included a full abdominal exploration. The US results were compared to findings at computed tomography (n = 115), clinical follow-up (n = 2244), or surgery (n = 47). Results: Overall, 2411 US abdominal studies were performed. In 5/2411 (0.2 %) patients, the US examinations were incomplete or indeterminate because of patient obesity and were therefore excluded from the study. Of the remaining 2406 US studies, 265 (11 %) were performed between 0 and 6 a.m., 770 (32 %) were performed between 6 a.m. and 12 midday, 673 (28 %) were performed between 12 midday. and 6 p.m., and the remaining 698 (29 %) were performed between 6 and 12 p.m. At US, the following post-traumatic injuries were correctly detected: 67 splenic lesions, 62 liver injuries, 13 renal contusions, 2 bowel lacerations, and 1 pancreatic injury. Nineteen patients had a sonogram with negative findings followed by CT with positive findings, while 18 patients had a sonogram with positive findings followed by CT with negative findings. The following rates were calculated for the US studies: true negative = 2224; true positive = 145; false positive = 18; false negative = 19; sensitivity = 88.4 %; specificity = 99.2 %; diagnostic accuracy = 98.2 %; positive predictive index = 88.9 %; negative predictive index = 99.1 %. Conclusion: Abdominal US provides a highly accurate, noninvasive imaging evaluation in patients who have sustained blunt abdominal trauma. This can be obtained particularly if a team of senior radiologists can perform the examination to provide high quality sonograms and be on site 24 h a day.     

Focused abdominal US in patients with trauma

PURPOSE: To evaluate the accuracy of focused abdominal ultrasonography (US) in detecting abdominal injuries that require in-hospital patient treatment in the setting of blunt abdominal trauma. MATERIALS AND METHODS: One thousand ninety patients with blunt abdominal trauma were assessed with focused abdominal US within 30 minutes of arrival at the hospital. Focused abdominal US results were positive if intra- or retroperitoneal fluid was detected. Patients with negative US results and no other major injuries were observed in the emergency department for 12 hours before discharge. Patients who deteriorated clinically after negative initial US underwent repeat US and/or emergency abdominopelvic computed tomography (CT). Patients with positive or indeterminate US results underwent emergency abdominopelvic CT. RESULTS: Nine hundred seventy-four (89%) patients had negative focused abdominal US results; eight of these underwent CT. Sixty-six (6%) had positive US results. Four (0.4%) had false-negative and 19 (1.7%) had false-positive US results. Twenty-seven (2.5%) had indeterminate US results; of these, five (18.5%) had positive CT results. One hundred twenty-four (11.4%) required emergency CT. After indeterminate cases were excluded, focused abdominal US had 94% sensitivity, 98% specificity, 78% positive predictive value, 100% negative predictive value, and 95% accuracy. CONCLUSION: Focused abdominal US has a high negative predictive value for major abdominal injury in patients with blunt abdominal trauma.     

Splenic echography in blunt abdominal trauma

Eighty emergency US exams of the spleen for blunt abdominal trauma were performed in 1988-1989 to evaluate US accuracy and reliability. A real-time scanner with convex probes (3.5 and 5 MHz) was employed. The results were confirmed at surgery and/or clinics and instrumental examinations. Nineteen patients were positive at US (1 false-positive); US patterns were: 16 focal lesions of the spleen--6 of them isolated, 7 associated with endoabdominal effusion, and 3 with increased splenic size and endoabdominal effusion--and 3 with isolated hemoperitoneum. Splenectomy was performed on 16/80 patients (20%): 13 of them were positive at US, while in 3 patients splenic lesions were not demonstrated. Five patients were followed with clinical and instrumental examinations to complete remission. Our results [85.7% sensitivity (18/21) and 71.4% specificity (15/21)] confirm US reliability in the evaluation of splenic lesions in blunt abdominal traumas.     

The role of imaging studies in pancreatic injury due to blunt abdominal trauma in children

BACKGROUND: The role imaging studies play in the choice of treatment in traumatic pancreas damage remains unclear. This study was performed to gain insight into the role of radiological studies in children 16 years of age or younger admitted to our hospital with pancreatic damage due to a blunt abdominal trauma. METHOD: Retrospectively, the radiological as well as patient clinical records were reviewed of all children admitted to our hospital between 1975 and 2003 with a pancreatic lesion due to blunt abdominal trauma. RESULTS: Thirty-four children with ages ranging from 3 to 14 years old were admitted with traumatic pancreas damage. Initially 33 children were treated conservatively for the pancreatic damage and only one had immediate surgery of the pancreas with a Roux-y pancreaticojejunostomy. Five other children had immediate surgery for other reasons. Overall, five children proved to have a pancreas transection on CT scans or during laparotomy. One child had a pancreas hematoma and 28 a pancreas contusion. In total 15 children developed a pseudocyst (44%), nine of which resolved spontaneously while six were treated by intervention. None of the children had residual morbidity, and there were no deaths. Considering the pancreas, the 11 available CT's were re-evaluated by two radiologists independently. Grade 3 pancreas damage (distal transection of the pancreatic duct) was diagnosed in five patients by radiologist A and four patients by radiologist B (80% match); Grade 1 was diagnosed in, respectively six and one patients (15% match). An US was performed on 19 children with 82 follow-up examinations, mostly for follow-up of the pseudocysts. CONCLUSION: Traumatic pancreas damage is a rare and difficult diagnosis. There is no straightforward answer for diagnostic imaging in blunt abdominal trauma in children. The diagnostic relevance of CT is limited. CT in combination with MRCP may be a better option for exclusion of pancreatic duct lesions.     

Blunt abdominal trauma: screening us in 2,693 patients

PURPOSE: To evaluate the accuracy of screening abdominal ultrasonography (US) in patients with blunt abdominal trauma. MATERIALS AND METHODS: Patients with blunt abdominal trauma underwent US. The abdomen and pelvis were scanned for free fluid, the visceral organs were assessed for heterogeneity, and duplex US was performed if necessary. Empty bladders were filled with 200-300 mL of sterile saline through a Foley catheter. US findings were considered positive if free fluid was present or if parenchymal abnormalities that could be consistent with trauma were detected. Screening US results were compared with findings of diagnostic peritoneal lavage, repeat US, computed tomography (CT), cystography, surgery, and/or autopsy and/or the clinical course. RESULTS: Findings from 2,693 US examinations were evaluated and were positive in 145 of 172 patients with injuries (sensitivity, 84%) and 64 (89%) of 72 patients who ultimately underwent laparotomy with surgical repair of injuries. False-negative findings were retroperitoneal injury, bowel injury, and intraperitoneal solid organ injury without hemoperitoneum. No patient with false-negative findings died. Specificity of US was 96% (2,429 of 2,521 patients), and overall accuracy was 96% (2,574 of 2,693 patients). Positive predictive value was 61% (145 of 237 patients), and negative predictive value was 99% (2,429 of 2,456 patients). CONCLUSION: Abdominal US is useful in screening for injury in patients with blunt abdominal trauma, and its use represents a notable change in institutional practice. Diagnostic peritoneal lavage is rarely performed, and CT is used when screening US findings are positive, when injury is clinically suspected despite negative US findings, or when US is not available.     

Computed tomography in blunt abdominal trauma: an analysis of clinical management and radiological findings.

We have retrospectively assessed the computed tomography (CT) findings in 92 patients suffering severe blunt abdominal trauma. Surgical findings and clinical follow-up were correlated with the CT findings. In nine patients CT was first used after emergency surgery and provided baseline data which was useful for further management. In two patients CT did not demonstrate small hepatic lacerations seen during previous surgery. No deaths were recorded. In 16 patients surgery followed CT within 24 h; there was good correlation between the CT and operative findings in 10 patients. However, CT failed to detect significant solid organ injury in five patients and was misleading (false positive) in another patient. There were two deaths amongst these 16 patients. Sixty-seven haemodynamically stable patients were initially managed non-operatively. Fifteen of these 67 patients had normal CT examinations; only one had subsequent laparotomy (for reasons unconnected with the trauma) where no injury was detected; there were no deaths. Of the 52 patients with an abnormal CT examination, 43 were successfully managed non-operatively. There were three deaths, including one where an injury missed at CT contributed to the demise of the patient. After an initial trial of non-operative management, the remaining six patients went to surgery where there was good concordance with the CT findings except for one missed renal injury. Active non-operative management of blunt abdominal trauma is widely accepted in haemodynamically stable patients and this report shows how CT supports this policy of surgical restraint in such cases. However, on review CT missed 13 injuries in nine patients overall; stricter attention to technique and better equipment may lead to improved results in the future.     

Gallbladder blunt trauma: comparison between radiologic and anatomo-surgical findings

PURPOSE: To assess the diagnostic accuracy and the possible role of ultrasonography (US) and Computed Tomography (CT) in a small group of patients who had a blunt abdominal trauma involving the gallbladder. MATERIAL AND METHODS: We retrospectively reviewed the US and CT findings of five patients with surgically confirmed post-traumatic gallbladder injury. The whole series consisted of 196 consecutive patients submitted to laparotomy for blunt abdominal trauma in the past 7 years. The following US and CT findings were considered at least suggestive of a possible post-traumatic gallbladder injury: pericholecystic fluid collection, ill-defined wall margin, collapsed lumen, high intraluminal density. RESULTS: At surgery, the following findings were observed: gallbladder hematoma (1 case), acute colecystitis (1 cases), gallbladder tear (3 cases), gallbladder tear associated with post-traumatic hepatic injuries (2 cases), duodenal tear (2 cases), hemoperitoneum alone (2 cases), hemoperitoneum associated with choleperitoneum (1 case), choleperitoneum alone (1 case). The US and CT findings were pericholecystic fluid collections (4 cases), ill-defined gallbladder wall margins (3 cases), collapsed lumen with intraluminal high density (1 case) and free intraperitoneal fluid collections (4 cases). They were suggestive of a possible post-traumatic gallbladder injury in all the five patients. CONCLUSIONS: The radiologic findings of our five patients were suggestive of a gallbladder damage but did not permit to distinguish minor from major injuries, the latter requiring surgical treatment. US proves to be a useful screening tool which can also help timing surgery in these patients. CT confirmed the US suspicions and also permitted accurate assessment of associated post-traumatic injuries to the liver and duodenum. Nevertheless, the clinical presentation was the most important factor as to the therapeutic management of these blunt abdominal trauma patients.     

Diagnostic performance of trauma US in identifying abdominal or pelvic free fluid and serious abdominal or pelvic injury

RATIONALE AND OBJECTIVES: This study assessed the ability of a six-point trauma ultrasound (US) evaluation (a) to identify the presence of free fluid in the abdomen or pelvis, with computed tomography (CT) and laparotomy used as diagnostic standards and (b) to predict the presence of abdominal or pelvic injury, particularly injury requiring surgical intervention. MATERIALS AND METHODS: Of 156 patients who underwent US evaluation for free fluid after sustaining blunt and penetrating trauma, 147 were entered into the prospective study and underwent follow-up CT and/or laparotomy (n = 79), in-hospital observation, or outpatient examination. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of US for identifying abdominal or pelvic free fluid were 69%, 100%, 100%, 95%, and 95%, respectively. The corresponding values for predicting abdominal and pelvic injury on the basis of free fluid status alone were 57%, 99%, 80%, 96%, and 95%, respectively. Performing repeated US examinations in patients with deteriorating clinical status decreased the false-negative rate by 50%, increasing the sensitivity for free fluid detection to 85% and the negative predictive value to 97%. Similarly, the sensitivity and negative predictive value for detection of injury increased to 71% and 97%, respectively. A learning curve was also observed, with 67% of the false-negative findings occurring in the first 3 months of the 19-month study. CONCLUSION: A six-point trauma US evaluation can reliably identify abdominal and pelvic free fluid, which can be a reliable indicator of abdominal or pelvic injury. Scanning conditions must be optimized, and the approach to clinical management must be cautious.     

Screening US for blunt abdominal trauma: a retrospective study

PURPOSE: To assess the accuracy of screening US in patients with blunt abdominal trauma first admitted in the trauma centre of our general hospital. MATERIALS AND METHODS: The reports of 864 abdominal US examinations of primary trauma patients (139 with major and 725 with minor injuries) obtained with standard protocols were retrieved. For each case, US reports were reviewed and compared to the best available reference standard. The accuracy of US was assessed by evaluating the method's overall ability to distinguish negative from positive cases by showing at least one of the lesions documented by the reference standard and its specific ability to depict injuries separately and independently. RESULTS: US exhibited a satisfactory overall ability to distinguish negative from positive patients (91.5% sensibility and 97.5% specificity in major trauma patients vs. 73.3% sensibility and 98.1% specificity in minor trauma patients) and a satisfactory specific ability to depict injuries separately and independently in major trauma patients. Of the 21/864 false negative reports (5 in patients with major and 16 in cases with minor trauma), only one affected patient management, a major trauma case, by delaying an emergency laparotomy. CONCLUSIONS: Its satisfactory accuracy for major trauma suggests that US could be employed not only to screen cases for emergency laparotomy but also as an alternative to screening CT. However, since major traumatic injuries generally carry an imperative indication for CT, especially as regards neurological, thoracic and skeletal evaluation, US has the not secondary task of performing a prompt preliminary examination using a simplified technique in the emergency room simultaneously with resuscitation.     

Cost reduction using ultrasound in blunt abdominal trauma

Ultrasound (US) provides a rapid, portable, and noninvasive method for evaluating the blunt trauma patient. In 1993, US was introduced into the workup of blunt abdominal trauma (BAT) at our institution and has rapidly become the modality of choice over computed tomography (CT) and diagnostic peritoneal lavage (DPL). In this study, the cost effectiveness of utilizing US in BAT was evaluated.We compared the number of DPLs and CTs performed during the 6-month period in 1993 preceding the incorporation of US with the number of CTs, DPLs, and USs performed during the last 6 months of 1994. Costs were determined by the finance department based on actual expenditures by the hospital, excluding physician fees, in 1994 U.S. dollars.Six hundred twenty-six patients were evaluated for BAT during the 6-month period in 1993. In this group, 450 patients had CT examinations, 160 had DPL, and 16 had both. This resulted in a cost of $254,316. During the last 6 months in 1994,564 patients were evaluated for BAT, including 470 USs, 175 CTs, and 11 DPLs. The cost for this group was $133,077, with a decrease in hospital expenditure of $170 per patient.We conclude that utilizing US in the evaluation of BAt leads to a significant cost reduction. Extrapolated over 1 year, with 1100 blunt abdominal trauma patients, the cost savings would be over $187,000.     

Gas in the sternoclavicular joints of patients with blunt chest trauma: significance and frequency of CT findings.

OBJECTIVE: In trauma patients, gas (vacuum phenomenon) in the sternoclavicular joints could represent sequelae of significant distraction forces and thus serve as a potential marker for severe intrathoracic injury. We evaluated the significance and frequency of the finding of gas in the sternoclavicular joints on chest CT of patients with blunt trauma. SUBJECTS AND METHODS: We prospectively studied all chest CT examinations performed at our institution over a 14-week period for the finding of gas in the sternoclavicular joints. Chest CT examinations (n = 267) were performed in 234 patients. We excluded data from follow-up CT examinations (n = 33), limiting our evaluation to the initial CT examination for each patient. Of the study population, 103 patients (83 men and 20 women) who ranged in age from 14 to 79 years (mean, 40 years) had sustained blunt chest trauma. For all trauma patients, we recorded the mechanism of injury and the associated thoracic injuries. RESULTS: CT revealed gas in the sternoclavicular joints in 47 patients (21%). Gas was unilateral in 27 patients and bilateral in 20 patients. Sternoclavicular joint gas was seen in 39 (38%) of the 103 trauma patients but was found in only eight (6%) of the 131 nontrauma patients (p < .0001). In the 39 trauma patients with sternoclavicular joint gas, associated thoracic injuries were seen in 17 patients (44%); either a sternal fracture or a retrosternal hematoma was seen in three patients. Radiographically evident thoracic injury was revealed in 20 (31%) of the 64 trauma patients who had no gas in the sternoclavicular joint; however, 10 of these 20 patients had either a sternal fracture or a mediastinal hematoma. CONCLUSION: Although gas in the sternoclavicular joints is more frequently seen in patients with blunt chest trauma than in patients undergoing chest CT for other indications, this finding does not indicate a greater risk of significant mediastinal or thoracic injury.     

Visceral injury without hemoperitoneum: A limitation of screening abdominal sonography for trauma

Abdominal sonography for the detection of hemoperitoneum has become increasingly popular as a screening test for visceral injury after blunt trauma. The purpose of this study was to determine the frequency, severity, and clinical significance (outcome) of abdominal organ injuries that occur without hemoperitoneum on the initial evaluation of blunt abdominal trauma patients.During a 12-month period, 3392 blunt trauma patients were admitted to our center. Sonographic studies were performed as an initial screening evaluation to determine the presence of hemoperitoneum in 772 (22.7%) of these patients. Abdominal visceral injuries were verified by computed tomography (CT) or surgery in 196 (5.8%) of all blunt trauma admissions. Sonography, CT, and operative findings were reviewed to determine the presence or absence of hemoperitoneum in patients with abdominal injury. Patients with abdominal visceral injury without hemoperitoneum were further analyzed to identify the type of injury and the management required.A total of 246 abdominal injuries were identified in 196 patients. Fifty (26%) patients with abdominal visceral injuries diagnosed by admission CT scan had no evidence of hemoperitoneum. Admission sonography performed in 15 (30%) of these 50 patients also showed no evidence of hemoperitoneum. Visceral injuries detected by CT in the patients without hemoperitoneum included 22 of 100 splenic injuries (22%), 18 of 91 hepatic injuries (20%), 12 of 26 renal injuries (46%), and 1 of 9 mesenteric injuries (11%). Surgery was required to manage injuries in 10 of these patients.Up to 26% of blunt trauma patients with abdominal visceral injuries do not have associated hemoperitoneum identified on admission abdominal CT or sonography. Dependence on hemoperitoneum as the sole criterion of abdominal visceral injury after blunt trauma will result in falsely negative examinations and will miss potentially significant injuries.     

Second-generation sonographic contrast agents in the evaluation of renal trauma

PURPOSE: The purpose of this study was to define the indications, diagnostic accuracy and limitations of second-generation sonographic contrast agents in the evaluation of patients with renal trauma. MATERIALS AND METHODS: Between March 2004 and April 2005, 277 patients with blunt abdominal trauma were evaluated. Twenty-eight out of 277 patients had renal lesions, the severity of which was graded according to the organ injury severity scale of the American Association for the Surgery of Trauma (AAST). All the patients enrolled in the study had minor trauma and were evaluated with baseline ultrasound (US), contrast-enhanced US after injection of a second-generation contrast agent (SonoVue) and, if positive, with multiphasic multidetector computed tomography (MDCT). RESULTS: Five out of 28 traumatic parenchymal lesions with perirenal fluid collection were identified at baseline US. All 28 renal parenchymal lesions, with or without perirenal or retroperitoneal haematoma, were identified at contrast-enhanced US. Multiphase MDCT confirmed all the cases that were positive at contrast-enhanced US and demonstrated the integrity of the urinary tract in the delayed phase. CONCLUSIONS: Our experience confirmed the diagnostic accuracy of second-generation sonographic contrast material both for diagnosis and for appropriate patient management. In particular, contrast-enhanced sonography proved to be a reliable technique for the evaluation and follow-up of low-grade renal injuries. Its main advantage is reduced radiation exposure, as fewer MDCT examinations are needed, whereas its limitation is the high cost of the technique if used in unselected patients.     

Screening US for blunt abdominal trauma: objective predictors of false-negative findings and missed injuries

PURPOSE: To determine the risk for missed injury in patients with blunt abdominal trauma and negative findings at screening ultrasonography (US) and with coexistent hematuria or fracture of the sixth through 12th ribs, lumbar spine, or pelvis. MATERIALS AND METHODS: From a database of 4,000 patients screened with US for blunt abdominal trauma at a level 1 trauma center, the 3,679 patients with negative US findings were retrospectively classified by consensus of two authors into high-risk (n = 494) and low-risk (n = 3,185) groups based on the presence of hypothetical predictors of missed injury: hematuria (n = 96) or fracture of the sixth through 12th ribs (n = 216), lumbar spine (n = 105), or pelvis (n = 174). Outcome in each patient was determined by the same two authors consensually after retrospective review of the trauma registry and all radiologic, surgical, and autopsy reports. The risk for missed abdominal injury was determined for each patient risk group and for each hypothetical predictor. Risks were statistically compared by using the Pearson chi2, Fisher exact, or Fisher-Freeman-Halton exact test, depending on expected frequencies. RESULTS: High-risk patients were 24 times more likely to have abdominal injuries after negative US findings (30 [6.1%] of 494) than were low-risk patients (eight [0.25%] of 3,185) (P <.001). Among high-risk patients, the absolute risks for missed abdominal injury associated with specific predictors were 15.6% (15 of 96 patients) for hematuria, 6.0% (13 of 216) for lower rib fractures, 7.6% (eight of 105) for lumbar spine fractures, and 5.2% (nine of 174) for pelvic fractures. Each of these risks was significantly higher for patients in the high-risk group than for those in the low-risk group (P <.001). CONCLUSION: Hematuria and fracture of the lower ribs, lumbar spine, or pelvis are objective predictors of missed abdominal injury in patients with blunt abdominal trauma and negative US findings, and such patients may benefit from additional screening with computed tomography.     

The collapsed inferior vena cava: CT evidence of hypovolemia

In a review of 100 patients undergoing abdominal CT for blunt abdominal trauma, seven had flattening of the infrahepatic inferior vena cava at multiple levels. In six of these patients, emergency surgery was required to control major hemorrhage. Three patients had hypotension documented during or shortly after abdominal CT. Five patients had major intraabdominal injuries, and one patient had massive hemorrhage from facial lacerations. The severity of the blood loss was not fully appreciated clinically in five of the six patients before CT. The seventh patient had no clinical evidence of significant blood loss; in this case the flattened inferior vena cava probably was related to a normal variant. In a group of 100 patients scanned for nonacute conditions, none had flattening of the infrahepatic inferior vena cava at multiple levels. Presence of a collapsed inferior vena cava may be CT evidence of significant hypovolemia from major blood loss and should prompt careful hemodynamic and central venous pressure monitoring.     

Multidetector CT: detection of active hemorrhage in patients with blunt abdominal trauma

OBJECTIVE: The aim of this study was to determine the imaging findings and the prevalence of active hemorrhage on contrast-enhanced multidetector CT in patients with blunt abdominal trauma. MATERIALS AND METHODS: Contrast-enhanced multidetector CT images of 165 patients with blunt abdominal trauma were reviewed for the presence of extravasated contrast agent, a finding that represents active hemorrhage. The site and appearance of the hemorrhage were noted on multidetector CT images. These findings were compared with surgical and angiographic results or with clinical follow-up. RESULTS: On multidetector CT images, active hemorrhage was detected in 22 (13%) of 165 patients with a total of 24 bleeding sites (14 intraperitoneal sites and 10 extraperitoneal sites). Active hemorrhage was visible most frequently as a jet of extravasated contrast agent (10/24 bleeding sites [42%]). Diffuse or focal extravasation was less frequently seen (nine [37%] and five [21%] bleeding sites, respectively). CT attenuation values measured in the aorta (mean, 199 H) were significantly higher than those measured in extravasated contrast material (mean, 155 H) (p < 0.001). Sixteen (73%) of 22 patients with active bleeding on multidetector CT images underwent immediate surgical or angiographic intervention. One patient received angiographic therapy 10 hr after undergoing multidetector CT, and five patients died between 1 and 3 hr after multidetector CT examination. CONCLUSION: Active hemorrhage in patients after blunt abdominal trauma is most frequently visible as a jet of extravasated contrast agent on multidetector CT. When extravasation is detected, immediate surgical or angiographic therapy is required.     

Blunt abdominal injury in the pregnant patient: detection with US

PURPOSE: To determine the accuracy of ultrasonography (US) for the detection of blunt intraabdominal injury in pregnant patients and to compare differences between pregnant and nonpregnant patients of childbearing age. MATERIALS AND METHODS: A retrospective review of results of all consecutive emergency blunt trauma US examinations performed at a level I trauma center from January 1995 to June 2002 was conducted. Data on demographics, free fluid location, and patient outcome were collected. Injuries were determined on the basis of results of computed tomography and/or laparotomy. The Student t test was used to detect differences between continuous variables, and chi(2) analysis was used to evaluate differences between proportions. RESULTS: A total of 2319 US examinations for blunt trauma were performed in girls and women between the ages of 10 and 50 years. There were 328 pregnant patients, 23 of whom had intraabdominal injury. The mean age of the pregnant patients was 24.7 years +/- 6.1 (standard deviation) (age range, 14-42 years). In pregnant patients, the sensitivity of US was 61% (14 of 23 patients), the specificity was 94.4% (288 of 305 patients), and the accuracy was 92.1% (302 of 328 patients). Pregnant patients were significantly more likely to have sustained injuries from assault (odds ratio: 2.6, P < .001). The most common pattern of free fluid accumulation detected at US in pregnant patients was that of fluid in the left and right upper quadrants and pelvis (n = 4, 29%); the second most common pattern was one of isolated pelvic fluid (n = 3, 21%). CONCLUSION: For detection of intraabdominal injury, US was less sensitive in pregnant patients than in nonpregnant patients but was highly specific in both subgroups. The sensitivity of US was highest in pregnant patients during the first trimester.     

The role of follow-up imaging in paediatric blunt abdominal trauma

AIM: To assess the role of follow-up imaging in paediatric blunt abdominal trauma. METHOD: All children who underwent CT scanning of their abdomen at our institution following acute blunt injury between January 1997 and December 2000 were included in the study. Case notes where researched for details regarding mechanism of injury, initial clinical presentation, acute management, complications and follow-up until discharge. Reports of imaging investigations were retrieved from the RIS database. RESULTS: In the study period 75 children underwent CT scanning of their abdomen as a primary investigation for acute blunt abdominal trauma. Of these, 12 were normal, 52 showed evidence of intra-abdominal organ injury and 11 showed findings other than abdominal organ injury. Of the 52 children that sustained intra-abdominal organ injury, 48 (92 percent) were treated conservatively. 4 (8 percent) underwent emergency surgery, 3 for bowel injury and 1 for renal trauma. Of the 48 that were treated conservatively, 9 had a complicated clinical course with 7 showing complications on follow-up imaging. The remaining 39 children had an uneventful clinical course with follow-up imaging by CT or US in 34. None showed complications that required a change in management. CONCLUSION: In our series, follow-up imaging did not contribute to further management in children with an uncomplicated clinical course following blunt abdominal trauma.     

CT detection of serious internal and skeletal injuries in patients with pelvic fractures

RATIONALE AND OBJECTIVES: The purpose of this study was to determine the percentage of patients with known pelvic fractures who have additional findings of intraabdominal injury, as diagnosed at abdominal computed tomography (CT), and to determine if patients with specific types or patterns of fractures are more likely to have additional injuries. MATERIALS AND METHODS: The authors reviewed the medical records of 200 consecutive patients (125 women, 75 men; age range, 4-86 years) who had been admitted to a level 1 trauma center with osseous pelvic injury secondary to blunt trauma and who had undergone abdominal CT examinations. Abdominal CT findings in these patients were classified as negative, positive, or minimal and correlated with mechanism of pelvic fracture. RESULTS: Sixty-five (32%) of the 200 patients had negative CT findings, 43 (22%) had findings attributable to the trauma but required no follow-up, and 92 (46%) had positive findings that required nonsurgical management or exploratory laparotomy. Additional pelvic fractures were identified in 63 (32%) patients. The highest prevalence of additional injuries was in patients with Malgaigne fractures (four of 15, 27%) or bilateral pubic rami fractures (six of 18, 33%). CONCLUSION: CT examinations revealed that 135 (68%) of 200 patients with pelvic fractures secondary to blunt trauma had concomitant internal or skeletal injuries and that 92 (46%) patients had injuries severe enough to require nonsurgical management or exploratory laparotomy. Patients with bilateral pubic rami fractures or Malgaigne fractures were particularly prone to additional injuries; therefore, abdominal CT examinations are recommended in these patients.     

Blunt abdominal trauma: clinical value of negative screening US scans

PURPOSE: To assess clinical and surgical outcomes in patients with blunt abdominal trauma and negative screening ultrasonographic (US) scans. MATERIALS AND METHODS: From a database of 4,000 patients who underwent screening US for suspected blunt abdominal trauma at a level 1 trauma center, the authors retrospectively identified 3,679 patients with negative US findings. In these patients, outcome was determined by means of retrospective review of the trauma registry and all radiologic, surgical, and autopsy reports. In patients with false-negative findings at screening US, all imaging studies and medical charts were also reviewed. Proportions were statistically compared by means of the Pearson chi(2) and Fisher exact tests. Monte Carlo estimation was applied when expected frequencies were low. RESULTS: Among the 3,679 patients with negative findings at screening US, 99.9% (n = 3,641) had no injuries (true-negative findings). Differences in true-negative rates as a function of year (P >.5) or time of day (P >.3) were not significant. Among the 3,641 patients with true-negative findings, 93.6% (n = 3,407) required no additional tests and 6.4% (n = 234) underwent computed tomography or other tests. The percentage of patients who underwent additional tests was significantly higher in the 1st year of the study (19.2%) than in subsequent years (all comparisons, P <.001). Thirty-eight patients had false-negative US findings for abdominal injury. The injuries that were missed in 24 patients were nonsurgical (those that were treated successfully without intervention or were considered minor at autopsy) and those in 14 patients were surgical (required surgical intervention). Cumulatively, 65 injuries were missed. The six most common injuries included retroperitoneal hematoma (n = 13) and injuries in the spleen (n = 10), liver (n = 9), kidney (n = 8), adrenal gland (n = 8), and small bowel (n = 7). Twenty-five of the 38 patients had no or trace hemoperitoneum. Mean diagnostic delay until recognition of missed injury was 16.8 hours +/- 4.3 (standard error of the mean). The missed injury was identified within 12 hours in 19 of the 38 patients and within 24 hours in 34. CONCLUSION: The combination of negative US findings and negative clinical observation virtually excludes abdominal injury in patients who are admitted and observed for at least 12-24 hours.