Influence of routine computed tomography on predicted survival from blunt thoracoabdominal trauma

Current Standards for and Clinical Impact of Emergency Radiology in Major Trauma

In industrialized countries, high energy trauma represents the leading cause of death and disability among people under 35 years of age. The two leading causes of mortality are neurological injuries and bleeding. Clinical evaluation is often unreliable in determining if, when and where injuries should be treated. Traditionally, surgery was the mainstay for assessment of injuries but advances in imaging techniques, particularly in computed tomography (CT), have contributed in progressively changing the classic clinical paradigm for major traumas, better defining the indications for surgery. Actually, the vast majority of traumas are now treated nonoperatively with a significant reduction in morbidity and mortality compared to the past. In this sense, another crucial point is the advent of interventional radiology (IR) in the treatment of vascular injuries after blunt trauma. IR enables the most effective nonoperative treatment of all vascular injuries. Indications for IR depend on the CT evidence of vascular injuries and, therefore, a robust CT protocol and the radiologist's expertise are crucial. Emergency and IR radiologists form an integral part of the trauma team and are crucial for tailored management of traumatic injuries.

Whole body CT versus selective radiological imaging strategy in trauma: an evidence-based clinical review

BACKGROUND

Trauma patients often present with injuries requiring resuscitation and further evaluation. Many providers advocate for whole body computed tomography (WBCT) for rapid and comprehensive diagnosis of life-threatening injuries.

OBJECTIVE

Evaluate the literature concerning mortality effect, emergency department (ED) length of stay, radiation, and incidental findings associated with WBCT.

DISCUSSION

Physicians have historically relied upon history and physical examination to diagnose life-threatening injuries in trauma. Diagnostic imaging modalities including radiographs, ultrasound, and computed tomography have demonstrated utility in injury detection. Many centers routinely utilize WBCT based on the premise this test will improve mortality. However, WBCT may increase radiation and incidental findings when used without considering pre-test probability of actionable traumatic injuries. Studies supporting WBCT are predominantly retrospective and incorporate trauma scoring systems, which have significant design weaknesses. The recent REACT-2 trial randomized trauma patients with high index of suspicion for actionable injuries to WBCT versus selective imaging and found no mortality difference. Additional prospective trials evaluating WBCT in specific trauma subgroups (e.g. polytrauma) are needed to evaluate benefit. In the interim, the available data suggests clinicians should adopt a selective imaging strategy driven by history and physical examination.

CONCLUSIONS

While observational data suggests an association between WBCT and a benefit in mortality and ED length of stay, randomized controlled data suggests no mortality benefit to this diagnostic tool. The literature would benefit from confirmatory studies of the use of WBCT in trauma sub-groups to clarify its impact on mortality for patients with specific injury patterns.

Torso Computed Tomography Can be Bypassed after Thorough Trauma Bay Examination of Patients who Fall from Standing

Reliance on CT imaging in the evaluation of low-impact blunt trauma is a major source of radiation exposure, cost, and resource utilization. This study sought to determine if torso (chest and abdomen) CT could be avoided in patients with ground level falls. This was a retrospective chart review of patients admitted to the trauma service between January 2013 and April 2014. The mechanism of injury was ground level fall or fall from sitting. Patient demographics, physical examination (PE) findings, imaging results, length of stay, and complications were reviewed. History and physical data were based on chief resident or attending documentation. A significant thoracic injury was defined as a hemothorax, a pneumothorax, greater than three rib fractures, or aortic injury. A significant abdominal injury was defined as a solid organ injury, an intra-abdominal hematoma, a hollow viscus injury, aortic injury, or a urologic injury. The trauma service evaluated 156 patients. Nine patients were excluded for intubation or Glasgow Coma Scale (GCS) < 13. Of the 147 remaining, mean age was 69 years, mean GCS was 14.8. A chest CT was obtained in 111 (76%). Eight (7%) had a significant thoracic injury. All patients with significant thoracic injury had positive examination findings. No patient with a normal PE was found to have a significant thoracic injury (negative predictive value of 100%). An abdominal CT was obtained in 86 (59%). Five (6%) were found to have a significant abdominal injury. All patients who had a significant radiographic injury had an abnormal PE (negative predictive value of 100%). In conclusion, thorough history and physical in the trauma bay allow the clinician to obtain selective torso CT imaging. Routine torso CT warrants re-evaluation in low-impact injury mechanisms as there appears to be little benefit compared with the resource utilization and expense.

Split bolus technique in polytrauma: a prospective study on scan protocols for trauma analysis

BACKGROUND

For the evaluation of severely injured trauma patients a variety of total body computed tomography (CT) scanning protocols exist. Frequently multiple pass protocols are used. A split bolus contrast protocol can reduce the number of passes through the body, and thereby radiation exposure, in this relatively young and vitally threatened population.

PURPOSE

To evaluate three protocols for single pass total body scanning in 64-slice multidetector CT (MDCT) on optimal image quality.

MATERIAL AND METHODS

Three total body CT protocols were prospectively evaluated in three series of 10 consecutive trauma patients. In Group A unenhanced brain and cervical spine CT was followed by chest-abdomen-pelvis CT in portovenous phase after repositioning of the arms. Group B underwent brain CT followed without arm repositioning by a one-volume contrast CT from skull base to the pubic symphysis. Group C was identical to Group A, but the torso was scanned with a split bolus technique. Three radiologists independently evaluated protocol quality scores (5-point Likert scale), parenchymal and vascular enhancement and artifacts.

RESULTS

Overall image quality was good (4.10) in Group A, more than satisfactory (3.38) in Group B, and nearly excellent (4.75) in Group C (P < 0.001). Interfering artifacts were mostly reported in Group B in the liver and spleen.

CONCLUSION

In single pass total body CT scanning a split bolus technique reached the highest overall image quality compared to conventional total body CT and one-volume contrast CT.

Evidence-based guidelines are equivalent to a liberal computed tomography scan protocol for initial patient evaluation but are associated with decreased computed tomography scan use, cost, and radiation exposure

BACKGROUND

We hypothesized that trauma patient evaluations using evidence-based treatment guidelines (evidence-based group [EBG]), which include serial examinations and limited computed tomography (CT) scans in an established trauma center, would be associated with equivalent outcomes but with decreased CT scan usage, decreased cost, and less radiation exposure compared with a liberal CT scan approach (conventional group [CONV]).

METHODS

Fifteen evidence-based treatment guidelines were developed using published literature and in collaboration with other institutional departments. These were implemented on July 1, 2010. Prospectively collected data during a 4-month period were compared with a similar period in 2008 when CONV was used.

RESULTS

In 2010 (EBG), there were 611 patients compared with 612 in 2008 (CONV). Their average Injury Severity Score was 11.93 versus 8.77 (p < 0.0001), and the total CT scans were 757 and 1194, respectively (p < 0.001). The average APACHE II and hospital length of stay did not significantly vary. No missed or delayed injuries were identified. Estimated CT scan charges were $1,842,534 versus $2,935,024. The average number of scans per patient were 1.2 (EBG) versus 1.9 (CONV). Regarding radiation dosimetry, the estimated average computed tomography dose index (CTDI) per patient were 36.7 versus 53.31 mGy, and the estimated average dose-length product per patient were 889.91 versus 1364.11 mGy·cm.

CONCLUSION

EBG, including serial examinations, provided equivalent diagnostic data to CONV for initial workup but reduced CT scan usage, CT scan charges, and average radiation exposure per patient. This strategy may be beneficial in institutions where serial monitoring can be assiduously provided.

LEVEL OF EVIDENCE

Case management study, level IV.

Accuracy of single-pass whole-body computed tomography for detection of injuries in patients with major blunt trauma

BACKGROUND

Contrast-enhanced whole-body computed tomography (also called "pan-scanning") is considered to be a conclusive diagnostic tool for major trauma. We sought to determine the accuracy of this method, focusing on the reliability of negative results.

METHODS

Between July 2006 and December 2008, a total of 982 patients with suspected severe injuries underwent single-pass pan-scanning at a metropolitan trauma centre. The findings of the scan were independently evaluated by two reviewers who analyzed the injuries to five body regions and compared the results to a synopsis of hospital charts, subsequent imaging and interventional procedures. We calculated the sensitivity and specificity of the pan-scan for each body region, and we assessed the residual risk of missed injuries that required surgery or critical care.

RESULTS

A total of 1756 injuries were detected in the 982 patients scanned. Of these, 360 patients had an Injury Severity Score greater than 15. The median length of follow-up was 39 (interquartile range 7-490) days, and 474 patients underwent a definitive reference test. The sensitivity of the initial pan-scan was 84.6% for head and neck injuries, 79.6% for facial injuries, 86.7% for thoracic injuries, 85.7% for abdominal injuries and 86.2% for pelvic injuries. Specificity was 98.9% for head and neck injuries, 99.1% for facial injuries, 98.9% for thoracic injuries, 97.5% for abdominal injuries and 99.8% for pelvic injuries. In total, 62 patients had 70 missed injuries, indicating a residual risk of 6.3% (95% confidence interval 4.9%-8.0%).

INTERPRETATION

We found that the positive results of trauma pan-scans are conclusive but negative results require subsequent confirmation. The pan-scan algorithms reduce, but do not eliminate, the risk of missed injuries, and they should not replace close monitoring and clinical follow-up of patients with major trauma.

Accuracy of single-pass whole-body computed tomography for detection of injuries in patients with major blunt trauma

BACKGROUND

Contrast-enhanced whole-body computed tomography (also called "pan-scanning") is considered to be a conclusive diagnostic tool for major trauma. We sought to determine the accuracy of this method, focusing on the reliability of negative results.

METHODS

Between July 2006 and December 2008, a total of 982 patients with suspected severe injuries underwent single-pass pan-scanning at a metropolitan trauma centre. The findings of the scan were independently evaluated by two reviewers who analyzed the injuries to five body regions and compared the results to a synopsis of hospital charts, subsequent imaging and interventional procedures. We calculated the sensitivity and specificity of the pan-scan for each body region, and we assessed the residual risk of missed injuries that required surgery or critical care.

RESULTS

A total of 1756 injuries were detected in the 982 patients scanned. Of these, 360 patients had an Injury Severity Score greater than 15. The median length of follow-up was 39 (interquartile range 7-490) days, and 474 patients underwent a definitive reference test. The sensitivity of the initial pan-scan was 84.6% for head and neck injuries, 79.6% for facial injuries, 86.7% for thoracic injuries, 85.7% for abdominal injuries and 86.2% for pelvic injuries. Specificity was 98.9% for head and neck injuries, 99.1% for facial injuries, 98.9% for thoracic injuries, 97.5% for abdominal injuries and 99.8% for pelvic injuries. In total, 62 patients had 70 missed injuries, indicating a residual risk of 6.3% (95% confidence interval 4.9%-8.0%).

INTERPRETATION

We found that the positive results of trauma pan-scans are conclusive but negative results require subsequent confirmation. The pan-scan algorithms reduce, but do not eliminate, the risk of missed injuries, and they should not replace close monitoring and clinical follow-up of patients with major trauma.