Derivation and validation of two decision instruments for selective chest CT in blunt trauma: a multicenter prospective observational study (NEXUS Chest CT)

ACR Appropriateness Criteria® Workup of Pleural Effusion or Pleural Disease

Pleural effusions are categorized as transudative or exudative, with transudative effusions usually reflecting the sequala of a systemic etiology and exudative effusions usually resulting from a process localized to the pleura. Common causes of transudative pleural effusions include congestive heart failure, cirrhosis, and renal failure, whereas exudative effusions are typically due to infection, malignancy, or autoimmune disorders. This document summarizes appropriateness guidelines for imaging in four common clinical scenarios in patients with known or suspected pleural effusion or pleural disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Pulmonary Contusion-An Unusual Clinical and Radiological Presentation: Case Report

Pulmonary contusion (PC), defined as damage to the lung parenchyma with edema and hemorrhage, has classically been associated with acceleration-deceleration injuries. It is a frequent pathology in clinical practice. However, its clinical presentation and imaging findings are nonspecific. Patients with this entity can present with findings that can range from mild dyspnea to life-threatening respiratory failure and hemodynamic instability. We present the case of a 61-year-old man, a former smoker, who presented to the emergency department after suffering blunt chest trauma. On admission, he complained of only mild shortness of breath, and his vital signs were typical. Initial imaging identified asymmetric pulmonary infiltrates and mediastinal lymphadenopathy; this was suspicious for additional pathology in addition to PC. After an exhaustive evaluation, a neoplastic or infectious disease process was ruled out. Even though the patient presented with a clinical deterioration of respiratory function compatible with secondary acute respiratory distress syndrome, there was a complete recovery after supportive measures and supplemental oxygen. In conclusion, the nonspecific clinical and imaging findings in patients with pulmonary contusion warrant a complete evaluation of these cases. An early diagnosis is essential to establish adequate support and monitoring to prevent possible complications that could worsen the patient's prognosis.

Accuracy of physician gestalt in prediction of significant abdominal and pelvic injury in adult blunt trauma patients

OBJECTIVE

Focusing on potential missed injury rates and sensitivity of low-risk of injury predictions, we sought to evaluate the accuracy of physician gestalt in predicting clinically significant injury (CSI) in the abdomen and pelvis among blunt trauma patients presenting to the emergency department (ED).

METHODS

We collected gestalt data on physicians caring for adult blunt trauma patients who received abdominal/pelvic computed tomography (CT) at three Level I and one Level II trauma centers. The primary outcome of CSI was defined as injury on abdominal/pelvic CT requiring hospitalization or intervention. Physicians evaluating trauma patients estimated the likelihood of CSI prior to abdominal/pelvic CT review (response choices: <2%, 2%-10%, 11%-20%, 21%-40%, >40%). We evaluated potential missed injury rates (prevalence of CSI) and sensitivity for prediction categories, as well as calibration and area under the receiver operating characteristic (AUROC) curve for overall physician gestalt.

RESULTS

Of 2030 patients, 402 (20%) had an injury on abdominal/pelvic CT and 270 (13%) had CSI. The <2% risk of CSI gestalt cutoff had a potential missed injury rate of 5.6% and a sensitivity of 95.2% (95% confidence interval [CI] 91.7%-97.3%). The 0%-10% cutoff of CSI gestalt had a potential missed injury rate of 6.3% (95% CI, 5.0%-7.9%) and a sensitivity of 75.2% (95% CI 69.5%-80.1%). With an overall AUROC of 0.699 (95% CI 0.679-0.719), physician gestalt was moderately accurate and calibrated for the midranges of predicted risk but poorly calibrated at the extremes.

CONCLUSIONS

Physician gestalt for the prediction of adult abdominal and pelvic CSI is moderately accurate and calibrated. However, the potential missed CSI rate and low sensitivity of the low perceived risk of injury cutoffs indicate that gestalt by itself is insufficient to direct selective abdominal/pelvic CT use in adult blunt trauma patient evaluation.

CT angiography of non-aortic thoracic arterial trauma

While aortic injury is the most commonly cited thoracic arterial injury, non-aortic arterial injuries represent an uncommon but significant source of morbidity and mortality in blunt and penetrating thoracic trauma patients. Knowledge of the spectrum of vascular injury and anatomic considerations that dictate patterns of associated thoracic hemorrhage will assist the radiologist in the accurate and efficient diagnosis of these injuries. This article provides a review of anatomy, pertinent clinical exam and CT angiography findings, as well as therapeutic options for non-aortic thoracic arterial trauma.

High risk and low prevalence diseases: Blast injuries

INTRODUCTION

Blast injury is a unique condition that carries a high rate of morbidity and mortality, often with mixed penetrating and blunt injuries.

OBJECTIVE

This review highlights the pearls and pitfalls of blast injuries, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Explosions may impact multiple organ systems through several mechanisms. Patients with suspected blast injury and multisystem trauma require a systematic evaluation and resuscitation, as well as investigation for injuries specific to blast injuries. Blast injuries most commonly affect air-filled organs but can also result in severe cardiac and brain injury. Understanding blast injury patterns and presentations is essential to avoid misdiagnosis and balance treatment of competing interests of patients with polytrauma. Management of blast victims can also be further complicated by burns, crush injury, resource limitation, and wound infection. Given the significant morbidity and mortality associated with blast injury, identification of various injury patterns and appropriate management are essential.

CONCLUSIONS

An understanding of blast injuries can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

A novel, evidence-based, comprehensive clinical decision support system improves outcomes for patients with traumatic rib fractures

BACKGROUND

Traumatic rib fractures are associated with high morbidity and mortality. Clinical decision support systems (CDSS) have been shown to improve adherence to evidence-based (EB) practice and improve clinical outcomes. The objective of this study was to investigate if a rib fracture CDSS reduced hospital length of stay (LOS), 90-day and 1-year mortality, unplanned ICU transfer, and the need for mechanical ventilation. The independent association of two process measures, an admission EB order set and a pain-inspiratory-cough score early warning system, with LOS were investigated.

METHODS

The CDSS was scaled across nine US trauma centers. Following multiple imputation, multivariable regression models were fit to evaluate the association of the CDSS on primary and secondary outcomes. As a sensitivity analysis, propensity score matching was also performed to confirm regression findings.

RESULTS

Overall, 3,279 patients met inclusion criteria. Rates of EB practices increased following implementation. On risk-adjusted analysis, in-hospital LOS preintervention versus postintervention was unchanged (incidence rate ratio [IRR], 1.06; 95% confidence interval [CI], 0.97-1.15, p = 0.2) but unplanned transfer to the ICU was reduced (odds ratio, 0.28; 95% CI, 0.09-0.84, p = 0.024), as was 1-year mortality (hazard ratio, 0.6; 95% CI, 0.4-0.89, p = 0.01). Provider utilization of the admission order bundle was 45.3%. Utilization was associated with significantly reduced LOS (IRR, 0.87; 95% CI, 0.77-0.98; p = 0.019). The early warning system triggered on 34.4% of patients; however, was not associated with a significant reduction in hospital LOS (IRR, 0.76; 95% CI, 0.55-1.06; p = 0.1).

CONCLUSION

A novel, user-centered, comprehensive CDSS improves adherence to EB practice and is associated with a significant reduction in unplanned ICU admissions and possibly mortality, but not hospital LOS.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Comparative study of National Emergency X-Radiography Utilization Study (NEXUS) chest algorithm and extended focused assessment with sonography for trauma (E-FAST) in the early detection of blunt chest injuries in polytrauma patients

Introduction

Chest imaging plays a prominent role in the assessment of patients with blunt trauma. Selection of the right approach at the right time is fundamental in the management of patients with blunt chest trauma.[1] A reliable, economic, bedside, and rapidly accomplished screening test can be pivotal. [2].

Objective

The aim of this study was to compare the accuracy of extended- focused assessment with sonography for trauma (E-FAST) to that of the National Emergency X-Radiography Utilisation Study (NEXUS) chest algorithm in detecting blunt chest injuries.

Methods

This descriptive cross-sectional study included 50 polytrauma patients with blunt chest trauma from the emergency centre of Suez Canal University Hospital. E-FAST and computed tomography (CT) were conducted, followed by reporting of NEXUS criteria for all patients. Blinding of the E-FAST performer and CT reporter were confirmed. The results of both the NEXUS algorithm and E-FAST were compared with CT chest results.

Results

The NEXUS algorithm had 100% sensitivity and 15.3% specificity, and E-FAST had 70% sensitivity and 96.7% specificity, in the detection of pneumothorax.In the detection of hemothorax, the sensitivity and specificity of the NEXUS algorithm were 90% and 7.5%, respectively, whereas E-FAST had a lower sensitivity of 80% and a higher specificity of 97.5%.

Conclusion

E-FAST is highly specific for the detection of hemothorax, pneumothorax, and chest injuries compared with the NEXUS chest algorithm, which demonstrated the lowest specificity. However, the NEXUS chest algorithm showed a higher sensitivity than E-FAST and hence can be used effectively to rule out thoracic injury.

Effect of the Extended Focused Assessment With Sonography for Trauma on the Screening Performance of the National Emergency X-Radiography Utilization Study Chest Decision Instrument

STUDY OBJECTIVE

Developed to decrease unnecessary thoracic computed tomography use in adult blunt trauma patients, the National Emergency X-Radiography Utilization Study (NEXUS) Chest clinical decision instrument does not include the extended Focused Assessment with Sonography in Trauma (eFAST). We assessed whether eFAST improves the NEXUS Chest clinical decision instrument's diagnostic performance and may replace the chest radiograph (CXR) as a predictor variable.

METHODS

We performed a secondary analysis of prospective data from 8 Level I trauma centers from 2011-2014. We compared performance of modified clinical decision instruments that (1) added eFAST as a predictor (eFAST-added clinical decision instrument), and (2) replaced CXR with eFAST (eFAST-replaced clinical decision instrument), in screening for blunt thoracic injuries.

RESULTS

One thousand nine hundred fifty-seven patients had documented computed tomography, CXR, clinical NEXUS criteria, and adequate eFAST; 624 (31.9%) patients had blunt thoracic injuries, and 126 (6.4%) had major injuries. Compared to the NEXUS Chest clinical decision instrument, the eFAST-added clinical decision instrument demonstrated unchanged screening performance for major injury (sensitivity 0.98 [0.94 to 1.00], specificity 0.28 [0.26 to 0.30]) or any injury (sensitivity 0.97 [0.95 to 0.98], specificity 0.21 [0.19 to 0.23]). The eFAST-replaced clinical decision instrument demonstrated unchanged sensitivity for major injury (sensitivity 0.93 [0.87 to 0.97], specificity 0.31 [0.29 to 0.34]) and decreased sensitivity for any injury (0.93 [0.91 to 0.951] versus 0.97 [0.953 to 0.98]).

CONCLUSION

In our secondary analysis, adding eFAST as a predictor variable did not improve the diagnostic screening performance of the original NEXUS Chest clinical decision instrument; eFAST cannot replace the CXR criterion of the NEXUS Chest clinical decision instrument.

Value of NEXUS chest rules in assessment of traumatic chest injuries; a systematic review and a meta-analysis

BACKGROUND

Although many studies have evaluated the diagnostic value of the National Emergency X-ray Utilization Studies (NEXUS) chest rules in assessment of traumatic chest injuries, there still is no consensus on this subject matter. Therefore, this systematic review and meta-analysis aims to review the current existing literature in order to evaluate the diagnostic value of NEXUS chest rules for assessment of traumatic chest injuries.

METHOD

Databases of Medline, Embase, Scopus and Web of Science were searched until August 20th, 2022. Two independent reviewers screened the articles related to the diagnostic value of NEXUS chest radiography, NEXUS chest CT-all and NEXUS chest-Major.

RESULTS

Data of 6 studies, on 23,741 patients, were included in this review. Since only one article assessed the value of NEXUS chest CT scan, the meta-analysis was performed only on NEXUS chest radiography rule. Pooled analysis on the results of 5 articles showed that the AUC of NEXUS chest radiography rule in assessment of traumatic chest injuries was 0.98 (95% CI: 0.96 to 0.99), with a sensitivity and specificity of 0.99 (95% CI: 0.98 to 0.99) and 0.32 (95% CI: 0.17 to 0.52), respectively. Positive and negative likelihood ratio of NEXUS chest radiography rule were 1.46 (95% CI: 1.12 to 1.90) and 0.04 (95% CI: 0.03 to 0.06). Overall diagnostic odds ratio was calculated to be 36.67 (95% CI: 19.17 to 70.16).

CONCLUSION

Our findings indicate that NEXUS chest radiography rule is a sensitive decision rule for assessment of traumatic chest injuries, but its specificity was found to be low. However, few articles have investigated the diagnostic value of NEXUS chest rules, especially the NEXUS chest CT scan, and more studies need to be done in order to strengthen the currently provided results.

CT as a first-line modality in elderly patients with stable blunt chest trauma

PURPOSE

Blunt thoracic injuries are common among elderly patients and may be a common cause of morbidity and death from blunt trauma injuries. We aimed to examine the impact of chest CT on the diagnosis and change of management plan in elderly patients with stable blunt chest trauma. We hypothesized that chest CT may play an important role in providing optimal management to this subgroup of trauma patients.

METHODS

A retrospective analysis was performed on all the admitted adult blunt trauma patients between January 2014 and December 2018. Stable blunt chest trauma patients with abbreviated injury severity (AIS) < 3 for extra-thoracic injuries confirmed with chest X-ray (CXR) and chest CT on admission or during hospitalization were included in the study. The AIS is an international scale for grading the severity of anatomic injury following blunt trauma. Primary outcome variables were occult injuries, change in management, need for surgical procedures, missed injuries, readmission rate, intensive care unit (ICU) and length of hospital stay.

RESULTS

There are 473 patients with blunt chest trauma included in the study. The study patients were divided into two groups according to the age range: group 1: 289 patients were included and aged 18-64 years; group 2: 184 patients were included and aged 65-99 years . Elderly patients in group 2 more often required ICU admission (11.4% vs. 5.2%), had a longer length of ICU stay (days) (median 11 vs. 6, p = 0.01), and the length of hospital stay (days) (median 14 vs. 6, p = 0.04). Injuries identified on chest CT has led to a change of management in 4.4% of young patients in group 1 and in 10.9% of elderly patients in group 2 with initially normal CXR. Chest CT resulted in a change of management in 12.8% of young patients in group 1 and in 25.7% of elderly patients in group 2 with initially abnormal CXR.

CONCLUSION

Chest CT led to a change of management in a substantial proportion of elderly patients. Therefore, we recommend chest CT as a first-line imaging modality in patients aged over 65 years with isolated blunt chest trauma.

Screening performance of the chest X-ray in adult blunt trauma evaluation: Is it effective and what does it miss?

BACKGROUND

Although chest x-ray (CXR) is often used as a screening tool for thoracic injury in adult blunt trauma assessment, its screening performance is unclear. Using chest CT as the referent standard, we sought to determine the screening performance of CXR for injury.

METHODS

We analyzed data from the NEXUS Chest CT study, in which we prospectively enrolled blunt trauma patients older than 14 years who received chest imaging as part of their evaluation at nine level I trauma centers. For this analysis, we included patients who had both CXR and chest CT. We used CT as the referent standard and categorized injuries as clinically major or minor according to an a priori expert panel classification.

RESULTS

Of 11,477 patients enrolled, 4501 had both CXR and chest CT; 1496 (33.2%) were found to have injury, of which 256 (17%) were classified as major injury. CXR missed injuries in 818 patients (54.7%), of which 63 (7.7%) were classified as major injuries. For injuries of major clinical significance, CXR had a sensitivity of 75.4% (95% confidence interval [CI] 69.6-80.4%), specificity of 86.2% (95% CI 85.1-87.2%), negative predictive value of 98.3 (95%CI 97.9-98.6%), and positive predictive value of 24.7 (95%CI 22.9-26.7%). For any injury CXR had a sensitivity of 45.3% (95% CI 42.8-47.9%), specificity of 96.6% (95% CI 95.9-97.2%), negative predictive value of 78% (95% CI 77.2-78.8%), and positive predictive value of 86.9% (95% CI 84.5-89.0%). The most common missed major injuries were pneumothorax (30/185; 16.2%), spinal fractures (19/39; 48.7%), and hemothorax (8/70; 11.4%). The most common missed minor injuries were rib fractures (381/836; 45.6%), pulmonary contusion (203/462; 43.9%), and sternal fractures (153/229; 66.8%).

CONCLUSIONS

When used alone, without other trauma screening criteria, CXR has poor screening performance for blunt thoracic injury.

Blunt Traumatic Aortic Injury in the Pan-scan Era

BACKGROUND

In the era of frequent head-to-pelvis computed tomography (CT) for adult blunt trauma evaluation, we sought to update teachings regarding aortic injury by determining 1) the incidence of aortic injury; 2) the proportion of patients with isolated aortic injury (without other concomitant thoracic injury); 3) the clinical implications of aortic injury (hospital mortality, length of stay [LOS], and rate of surgical interventions); and 4) the screening value of traditional risk factors/markers (such as high-energy mechanism and widened mediastinum on chest x-ray [CXR]) for aortic injury, compared to newer criteria from the recently developed NEXUS Chest CT decision instrument (DI).

METHODS

We conducted a preplanned analysis of patients prospectively enrolled in the NEXUS Chest studies at 10 Level I trauma centers with the following inclusion criteria: age > 14 years, blunt trauma within 6 hours of ED presentation, and receiving chest imaging during ED trauma evaluation.

RESULTS

Of 24,010 enrolled subjects, 42 (0.17%, 95% confidence interval [CI] = 0.13% to 0.24%) had aortic injury. Most patients (79%, 95% CI = 64% to 88%) had an associated thoracic injury, with rib fractures, pneumothorax/hemothorax, and pulmonary contusion occurring most frequently. Compared to patients without aortic injury this cohort had similar mortality (9.5%, 95% CI = 3.8% to 22.1% vs. 5.8%, 95% CI = 5.4% to 6.3%), longer median hospital LOS (11 days vs. 3 days, p < 0.01), and higher median Injury Severity Score (29 vs. 5, p < 0.001). High-energy mechanism and widened mediastinum on CXR had low sensitivity for aortic injury (76% [95% CI = 62% to 87%] and 33% [95% CI = 21% to 49%], respectively), compared to the NEXUS Chest CT DI (sensitivity 100% [95% CI = 92% to 100%]).

CONCLUSIONS

Aortic injury is rare in adult ED blunt trauma patients who survive to receive imaging. Most ED aortic injury patients have associated thoracic injuries and survive to hospital discharge. Widened mediastinum on CXR and high-energy mechanism have relatively low screening sensitivity for aortic injury, but the NEXUS Chest DI detected all cases.

Clinical predictors of abnormal chest CT scan findings following blunt chest trauma: A cross-sectional study

PURPOSE

Some surgeons believe that chest computed tomography (CT) scan should be used more prudently in management of blunt chest trauma patients. This study aimed to evaluate the clinical predictors of abnormal chest CT scan findings in trauma patients.

METHODS

This cross-sectional study was conducted on blunt chest trauma patients aged ≥18 years who were referred to the emergency departments of two educational hospitals and underwent chest CT scan. These patients were enrolled in the study using a non-probability sampling method. The exclusion criteria included: class III or IV hemodynamic shock, need for immediate surgical or neurosurgical interventions, penetrating trauma, lack of required information, and pregnancy. Demographic factors, accident details, trauma mechanism, vital signs, and level of consciousness in predicting abnormal chest CT scan findings were evaluated. Analysis was performed using IBM SPSS statistics 21.

RESULTS

A total of 977 patients (male 51.5%, female 48.5%) with the mean age of (41.71 ± 14.24) years, range 18-88 years were studied; 34.2% of them with high energy trauma mechanism. With 334 (34.2%) patients had abnormal findings on chest X-ray (CXR) and 332 (34.0%) cases had an abnormal findings on chest CT scan (agreement rate was 99.4%). There was a significant correlation between male gender (p < 0.0001), GCS<15 (p < 0.0001), high energy trauma mechanism (p < 0.0001), unstable hemodynamics (p < 0.01), and clinical signs and symptoms (p < 0.0001) with chest CT findings. Chest wall deformity (odds = 8; p < 0.0001), generalized tenderness (odds = 6.6, p < 0.0001), and decreased cardiac sound (odds = 3.8, p < 0.0001) were the important and independent clinical predictors of abnormal chest CT scan findings.

CONCLUSION

Based on the findings, chest wall deformity, generalized tenderness, decreased cardiac sound, distracting pain, chest wall tenderness, high energy trauma mechanism, male gender, respiratory rate > 20 breathes/min, decreased pulmonary sound, and chest wall crepitation were independent clinical predictors of abnormal chest CT scan findings following blunt trauma.

Thoracic Spine Fracture in the Panscan Era

STUDY OBJECTIVE

In the current era of frequent chest computed tomography (CT) for adult blunt trauma evaluation, many minor injuries are diagnosed, potentially rendering traditional teachings obsolete. We seek to update teachings in regard to thoracic spine fracture by determining how often such fractures are observed on CT only (ie, not visualized on preceding trauma chest radiograph), the admission rate, mortality, and hospital length of stay of thoracic spine fracture patients, and how often thoracic spine fractures are clinically significant.

METHODS

This was a preplanned analysis of prospectively collected data from the NEXUS Chest CT study conducted from 2011 to 2014 at 9 Level I trauma centers. The inclusion criteria were older than 14 years, blunt trauma occurring within 6 hours of emergency department (ED) presentation, and chest imaging (radiography, CT, or both) during ED evaluation.

RESULTS

Of 11,477 enrolled subjects, 217 (1.9%) had a thoracic spine fracture; 181 of the 198 thoracic spine fracture patients (91.4%) who had both chest radiograph and CT had their thoracic spine fracture observed on CT only. Half of patients (49.8%) had more than 1 level of thoracic spine fracture, with a mean of 2.1 levels (SD 1.6 levels) of thoracic spine involved. Most patients (62%) had associated thoracic injuries. Compared with patients without thoracic spine fracture, those with it had higher admission rates (88.5% versus 47.2%; difference 41.3%; 95% confidence interval 36.3% to 45%), higher mortality (6.3% versus 4.0%; difference 2.3%; 95% confidence interval 0 to 6.7%), and longer length of stay (median 9 versus 6 days; difference 3 days; P<.001). However, thoracic spine fracture patients without other thoracic injury had mortality similar to that of patients without thoracic spine fracture (4.6% versus 4%; difference 0.6%; 95% confidence interval -2.5% to 8.6%). Less than half of thoracic spine fractures (47.4%) were clinically significant: 40.8% of patients received thoracolumbosacral orthosis bracing, 10.9% had surgery, and 3.8% had an associated neurologic deficit.

CONCLUSION

Thoracic spine fracture is uncommon. Most thoracic spine fractures are associated with other thoracic injuries, and mortality is more closely related to these other injuries than to the thoracic spine fracture itself. More than half of thoracic spine fractures are clinically insignificant; surgical intervention is uncommon and neurologic injury is rare.

Hemothorax: A Review of the Literature

Hemothorax is a collection of blood in the pleural cavity usually from traumatic injury. Chest X-ray has historically been the imaging modality of choice upon arrival to the hospital. The sensitivity and specificity of point-of-care ultrasound, specifically through the Extended Focal Assessment with Sonography in Trauma (eFAST) protocol has been significant enough to warrant inclusion in most Level 1 trauma centers as an adjunct to radiographs.^1,2 If the size or severity of a hemothorax warrants intervention, tube thoracostomy has been and still remains the treatment of choice. Most cases of hemothorax will resolve with tube thoracostomy. If residual blood remains within the pleural cavity after tube thoracostomy, it is then considered to be a retained hemothorax, with significant risks for developing late complications such as empyema and fibrothorax. Once late complications occur, morbidity and mortality increase dramatically and the only definitive treatment is surgery. In order to avoid surgery, research has been focused on removing a retained hemothorax before it progresses pathologically. The most promising therapy consists of fibrinolytics which are infused into the pleural space, disrupting the hemothorax, allowing for further drainage. While significant progress has been made, additional trials are needed to further define the dosing and pharmacokinetics of fibrinolytics in this setting. If medical therapy and early procedures fail to resolve the retained hemothorax, surgery is usually indicated. Surgery historically consisted solely of thoracotomy, but has been largely replaced in non-emergent situations by video-assisted thoracoscopy (VATS), a minimally invasive technique that shows considerable improvement in the patients' recovery and pain post-operatively. Should all prior attempts to resolve the hemothorax fail, then open thoracotomy may be indicated.

CT scanning in blunt chest trauma: validation of decision instruments

ABSTRACT Objective: to perform an external validation of two clinical decision instruments (DIs) - Chest CT-All and Chest CT-Major - in a cohort of patients with blunt chest trauma undergoing chest CT scanning at a trauma referral center, and determine if these DIs are safe options for selective ordering of chest CT scans in patients with blunt chest trauma admitted to emergency units. Methods: cross-sectional study of patients with blunt chest trauma undergoing chest CT scanning over a period of 11 months. Chest CT reports were cross-checked with the patients’ electronic medical record data. The sensitivity and specificity of both instruments were calculated. Results: the study included 764 patients. The Chest CT-All DI showed 100% sensitivity for all injuries and specificity values of 33.6% for injuries of major clinical significance and 40.4% for any lesion. The Chest CT-Major DI had sensitivity of 100% for injuries of major clinical significance, which decreased to 98.6% for any lesions, and specificity values of 37.4% for injuries of major clinical significance and 44.6% for all lesions. Conclusion: both clinical DIs validated in this study showed adequate sensitivity to detect chest injuries on CT and can be safely used to forego chest CT evaluation in patients without any of the criteria that define each DI. Had the Chest CT-All and Chest CT-Major DIs been applied in this cohort, the number of CT scans performed would have decreased by 23.1% and 24.6%, respectively, resulting in cost reduction and avoiding unnecessary radiation exposure.

A case of fatal trauma evaluated using a portable X-ray system at the scene

Objective: To demonstrate the use of a portable X-ray system at the scene.

Patient: A 59-year-old man collapsed under a small power shovel and was discovered by his colleague. The fire department dispatched an ambulance and requested the dispatch of a doctor helicopter (DH) immediately after receiving the emergency call. When the staff of the DH used a portable X-ray system to assess the patient at the rendezvous point, he was found to have experienced a cardiac arrest with deformity of the face. Portable chest X-ray in the ambulance revealed decreased radiolucency of the lung fields without pneumothorax, and tracheal tube insertion was successful. Portable pelvic X-ray also showed no trauma. Portable cranial X-ray revealed orbital fracture. Although we urgently transported the patient to our hospital by the DH, he unfortunately died of circulatory arrest caused by his severe injuries. Based on the portable X-ray findings obtained at the scene, we suspected that the patient’s cardiac arrest had been caused by severe head and/or neck injuries.

Conclusion: This portable X-ray system may be able to change and facilitate the management of patients with trauma dramatically by simplifying prehospital diagnoses even in rural areas.

Added Value of Bone Suppression Image in the Detection of Subtle Lung Lesions on Chest Radiographs with Regard to Reader's Expertise

BACKGROUND

Chest radiographs (CXR) are the most commonly used imaging techniques by various clinicians and radiologists. However, detecting lung lesions on CXR depends largely on the reader's experience level, so there have been several trials to overcome this problem using post-processing of CXR. We investigated the added value of bone suppression image (BSI) in detecting various subtle lung lesions on CXR with regard to reader's expertise.

METHODS

We applied a software program to generate BSI in 1,600 patients in the emergency department. Of them, 80 patients with subtle lung lesions and 80 patients with negative finding on CXR were retrospectively selected based on the subtlety scores on CXR and CT findings. Ten readers independently rated their confidence in deciding the presence or absence of a lung lesion at each of 960 lung regions on the two separated imaging sessions: CXR alone vs. CXR with BSI.

RESULTS

The additional use of BSI for all readers significantly increased the mean area under the curve (AUC) in detecting subtle lung lesions (0.663 vs. 0.706; P < 0.001). The less experienced readers were, the more AUC differences increased: 0.067 (P < 0.001) for junior radiology residents; 0.064 (P < 0.001) for non-radiology clinicians; 0.044 (P < 0.001) for senior radiology residents; and 0.019 (P = 0.041) for chest radiologists. The additional use of BSI significantly increased the mean confidence regarding the presence or absence of lung lesions for 213 positive lung regions (2.083 vs. 2.357; P < 0.001) and for 747 negative regions (1.217 vs. 1.195; P = 0.008).

CONCLUSION

The use of BSI increases diagnostic performance and confidence, regardless of reader's expertise, reduces the impact of reader's expertise and can be helpful for less experienced clinicians and residents in the detection of subtle lung lesions.

Blunt traumatic scapular fractures are associated with great vessel injuries in children

BACKGROUND

Patients with stable blunt great vessel injury (GVI) can have poor outcomes if the injury is not identified early. With current pediatric trauma radiation reduction efforts, these injuries may be missed. As a known association between scapular fracture and GVI exists in adult blunt trauma patients, we examined whether that same association existed in pediatric blunt trauma patients.

METHODS

Bluntly injured patients younger than 18 years old were identified from 2012 to 2014 in the National Trauma Data Bank. Great vessel injury included all major thoracic vessels and carotid/jugular. Demographics of patients with and without scapular fracture were compared with descriptive statistics. The χ test was used to examine this association using SAS Version 9.4 (SAS Institute, Inc, Cary, NC).

RESULTS

We found a significant association between pediatric scapular fracture and GVI. Of 291,632 children identified, 1,960 had scapular fractures. Children with scapular fracture were 10 times more likely to have GVI (1.2%) compared to those without (0.12%, p < 0.0001). Most common GVI seen were carotid artery, thoracic aorta, and brachiocephalic or subclavian artery or vein. Children with both scapular fracture and GVI were most commonly injured by motor vehicles (57% collision, 26% struck).

CONCLUSIONS

Injured children with blunt scapular fracture have a 10-fold greater risk of having a GVI when compared to children without scapular fracture. Presence of blunt traumatic scapular fracture should have appropriate index of suspicion for a significant GVI in pediatric trauma patients.

LEVEL OF EVIDENCE

Epidemiologic and prognostic study, level III; Therapeutic, level IV.

Thoracolumbar Evaluation in the Low-Risk Trauma Patient: A Pilot Study Towards Development of a Clinical Decision Rule to Avoid Unnecessary Imaging in the Emergency Department

BACKGROUND

Thoracolumbar (TL) injury is a common finding in the severely injured multi-trauma patient. However, the incidence and pattern of TL injury in patients with milder trauma is unclear.

OBJECTIVE

The aim of this study was to collect and analyze evidence for the development of a clinical decision rule (CDR) to evaluate the TL spine in patients with non-severe blunt trauma and avoid dedicated imaging in low-risk cases.

METHODS

Adult patients with blunt trauma who presented to a major academic center (May 2016 to October 2017) and received dedicated imaging of the TL spine were included. Exclusion criteria consisted of any coexisting condition preventing the acquisition of history or examination. The primary endpoint is TL spine injury requiring orthopedic evaluation, bracing/orthosis, or surgery. Preliminary CDR derivation was performed with recursive partitioning.

RESULTS

Of 4612 patients screened, 1049 (22.7%) met inclusion criteria. Thirty-six (3.4%) patients were found to have TL spine injury, of which 88.9% received spinal bracing, orthosis, or surgery. Absence of midline tenderness conveyed the highest negative predictive value, followed by a non-severe mechanism of injury, lack of neurologic examination findings, and age < 65 years. No patients in this cohort with these four findings had a TL spine injury.

CONCLUSIONS

In certain lower-risk blunt trauma patients < 65 years of age, focused examination combined with mechanism of injury may be highly sensitive (100%) to rule out TL injury without the need for dedicated imaging. However, validation is necessary, given multiple study limitations. Potential instrument to screen for TL injury in minor trauma: TL injury is unlikely if all four of the following are present: 1) no midline back tenderness or deformity, 2) no focal neurologic signs or symptoms or altered mentation, 3) age < 65 years; and 4) lack of severe mechanism of injury, for example, fall greater than standing, motor-vehicle collision with rollover/ejection/pedestrian or unenclosed vehicle, and assault with a weapon.

An impact analysis of the NEXUS Chest CT clinical decision rule

BACKGROUND

The NEXUS Chest CT clinical decision rules (CDRs) have been proposed to safely guide selective chest CT use in blunt trauma evaluation. We conducted a cost-effectiveness analysis of the NEXUS Chest CT CDR to determine its impact on missed injuries, cost, and radiation exposure.

METHODS

We constructed a decision model comparing two strategies: implementation of the NEXUS Chest CDR vs. usual care in the evaluation of adults with blunt trauma. We derived probabilities, clinical outcomes, effective radiation dose (ERD) from the NEXUS Chest CT validation cohort and costs from the Charge-master at the primary study site. Our primary outcomes were cost and effective radiation dose (ERD) per missed clinically significant injury (CSI).

RESULTS

Using a hypothetical cohort of 1000 adults with blunt chest trauma in each arm, the base case model projected that the implementation of the CDR would result in 161 fewer chest CTs, 0.08 additional missed CSIs, a cost savings of $136,432 and a decrease in 1435 mSv, as compared to Usual Care. To detect one additional CSI, the Usual Care strategy would require 2015 more chest CTs with a cost of $1.8 million and 17,934 mSv more radiation.

CONCLUSIONS

Compared to usual care, implementation of the NEXUS Chest CT Major CDR in the evaluation of adults with blunt trauma would greatly reduce CT associated costs and radiation exposure with a slight increased risk of missed CSIs.

Ageing population has changed the nature of major thoracic injury

Introduction

An increasing proportion of the major trauma population are older persons. The pattern of injury is different in this age group and serious chest injuries represent a significant subgroup, with implications for trauma system design. The aim of this study was to examine trends in thoracic injuries among major trauma patients in an inclusive trauma system.

Methods

This was a retrospective review of all adult cases of major trauma with thoracic injuries of Abbreviated Injury Scale score of 3 or more, using data from the Victorian State Trauma Registry from 2007 to 2016. Prevalence and pattern of thoracic injury was compared between patients with multitrauma and patients with isolated thoracic injury. Poisson regression was used to determine whether population-based incidence had changed over the study period.

Results

There were 8805 cases of hospitalised major trauma with serious thoracic injuries. Over a 10-year period, the population-adjusted incidence of thoracic injury increased by 8% per year (incidence rate ratio [IRR] 1.08, 95% CI 1.07 to 1.09). This trend was observed across all age groups and mechanisms of injury. The greatest increase in incidence of thoracic injuries, 14% per year, was observed in people aged 85 years and older (IRR 1.14, 95% CI 1.09 to 1.18).

Conclusions

Admissions for thoracic injuries in the major trauma population are increasing. Older patients are contributing to an increase in major thoracic trauma. This is likely to have important implications for trauma system design, as well as morbidity, mortality and use of healthcare resources.

Pulmonary contusion

Lung contusion resulting from chest trauma may be present various clinical pictures. It quite often remains unrecognized and is only suspected later when severe complications have developed. Lung contusion may present in association with chest trauma but may also occur alone. It has to be emphasized, that lung contusion as a clinical identity does not necessarily require a blunt or penetrating chest to be in the background. Nowadays, as a result of traffic accidents, following high energy deceleration, lung contusion may present without an actual tissue damage in the chest wall as a condition initiating an independent, life-threatening generalised process. Although lung contusion shows similarities to blast injury of the lung with respect to clinical consequences, other factors play a role in its aetiology and pathology. Its description and recognition as an independent pathology is not simple. Several approaches exist: thoracic trauma, pulmonary contusion, pulmonary laceration, lung contusion; although these may show similar clinical signs, manifest in different pathologies. Pathologies with similar meaning and possibly similar clinical course cannot, actually, be differentiated; they may accompany other injuries to the trunk, skull or extremities, which, alone, are associated with high morbidity and mortality. Generally, it can be declared that besides high energy, blunt injuries affecting the trunk, lung contusion, has been an often neglected additional radiological finding attached to the main report, despite the fact, that its late consequences crucially determine the prospects of the injured.

Blunt Trauma Abdominal and Pelvic Computed Tomography Has Low Yield for Injuries in More Than One Anatomic Region

Introduction

Most trauma centers order abdominal and pelvic computed tomography (CT) as an automatically paired CT for adult blunt trauma evaluation. However, excessive CT utilization adds risks of excessive exposure to ionizing radiation, the need to work up incidental findings (leading to unnecessary and invasive tests), and greater costs. Examining a cohort of adult blunt trauma patients that received paired abdominal and pelvic (A/P) CT, we sought to determine the diagnostic yield of clinically significant injuries (CSI) in the following: 1) the abdomen alone; 2) the pelvis alone; 3) the lumbosacral spine alone; and 4) more than one of these anatomic regions concomitantly.

Methods

In this retrospective study, we reviewed the imaging and hospital course of a consecutive sample of blunt trauma activation patients older than 14 years of age who received paired A/P CT during their blunt trauma assessments at an urban Level I trauma center from April through October 2014. Categorization of CSI was determined according to an a priori, expert panel-derived classification scheme.

Results

The median age of the 689 patients who had A/P CT was 48 years old; 68.1% were male; 64.0% were admitted, and hospital mortality was 3.6%. CSI yields were as follows: abdomen 2.2% (95% confidence interval [CI] [1.3–3.6%]); pelvis 2.9% (95% CI [1.9–4.4%]); lumbosacral spine 0.6% (95% CI [0.2–1.5%]); both abdomen and pelvis 0.3% (95% CI [0.1–1.1%]); both the abdomen and lumbosacral spine 0.6% (0.2–1.5%); both the pelvis and lumbosacral spine 0.1% (0.0–0.8%); all three regions – abdomen, pelvis and lumbosacral spine – 0.1% (0.0–0.8%).

Conclusion

Automatic pairing of A/P CT has very low diagnostic yield for CSI in both the abdomen and pelvis. These data suggest a role for selective CT imaging protocols that image these regions individually instead of automatically as a pair.

Computed Tomography Window Blending: Feasibility in Thoracic Trauma

RATIONALE AND OBJECTIVES

This study aims to demonstrate the feasibility of processing computed tomography (CT) images with a custom window blending algorithm that combines soft-tissue, bone, and lung window settings into a single image; to compare the time for interpretation of chest CT for thoracic trauma with window blending and conventional window settings; and to assess diagnostic performance of both techniques.

MATERIALS AND METHODS

Adobe Photoshop was scripted to process axial DICOM images from retrospective contrast-enhanced chest CTs performed for trauma with a window-blending algorithm. Two emergency radiologists independently interpreted the axial images from 103 chest CTs with both blended and conventional windows. Interpretation time and diagnostic performance were compared with Wilcoxon signed-rank test and McNemar test, respectively. Agreement with Nexus CT Chest injury severity was assessed with the weighted kappa statistic.

RESULTS

A total of 13,295 images were processed without error. Interpretation was faster with window blending, resulting in a 20.3% time saving (P < .001), with no difference in diagnostic performance, within the power of the study to detect a difference in sensitivity of 5% as determined by post hoc power analysis. The sensitivity of the window-blended cases was 82.7%, compared to 81.6% for conventional windows. The specificity of the window-blended cases was 93.1%, compared to 90.5% for conventional windows. All injuries of major clinical significance (per Nexus CT Chest criteria) were correctly identified in all reading sessions, and all negative cases were correctly classified. All readers demonstrated near-perfect agreement with injury severity classification with both window settings.

CONCLUSIONS

In this pilot study utilizing retrospective data, window blending allows faster preliminary interpretation of axial chest CT performed for trauma, with no significant difference in diagnostic performance compared to conventional window settings. Future studies would be required to assess the utility of window blending in clinical practice.

Scapular Fractures in the Pan-scan Era

BACKGROUND

Scapular fractures have been traditionally taught to be associated with significant injuries and major morbidity. As we demonstrated with sternal fracture, pulmonary contusion, and rib fracture, increased chest computed tomography (CT) utilization and head-to-pelvis CT (pan-scan) protocols in blunt trauma evaluation, however, may diagnose minor, clinically irrelevant scapular fractures, possibly rendering previous teachings obsolete.

OBJECTIVES

The objectives were to determine the 1) percentages of scapular fractures seen on chest CT only (SOCTO) versus seen on both chest x-ray (CXR) and CT and of isolated scapular fracture (scapular fracture without other thoracic injuries); 2) frequencies of associated thoracic injury with scapular fracture; and 3) proportion of patients admitted, mortality, hospital length of stay, and injury severity scores (ISS), comparing four patient groups: scapular fracture, nonscapular fracture, scapular fracture SOCTO, and isolated scapular fracture.

METHODS

We conducted a preplanned analysis of patients prospectively enrolled in the NEXUS Chest CT study at nine Level I trauma centers with the following inclusion criteria: age > 14 years, blunt trauma within 6 hours of ED presentation, and receiving chest imaging during ED trauma evaluation.

RESULTS

Of 11,477 subjects, 4,501 (39.2%) patients who had both CXR and chest CT and 2.7% of these had scapular fractures; 60.3% of these were SOCTO and 23 (19.0%) were isolated scapular fracture. The most commonly associated thoracic injuries were rib fracture, pulmonary contusion, pneumothorax, and thoracic spine fracture and all injuries were more common in scapular fracture patients than nonscapular fracture patients. Although scapular fracture patients had higher admission rates (86.8% vs. 47.4%; difference in proportions = 39.4% [95% confidence interval {CI} = 32.8% to 44.1%]), ISS (21 vs. 5), and length of stay (9.2 days vs. 5.6 days; mean difference = 3.4 days [95% CI = 2.1 to 4.7 days]) than patients without scapular fracture, their hospital mortality was not significantly different (5.6% vs. 3.0%; difference in proportions = 2.6% [95% CI = -8.2% to 0.3%]; unadjusted odds ratio = 1.9 [95% CI = 0.9 to 4.2]). Patients with scapular fracture SOCTO and isolated scapular fracture had higher admission rates and median ISS than nonscapular fracture patients, but their mortality was similar.

CONCLUSIONS

Under current blunt trauma imaging protocols that commonly include chest CT, most scapular fractures are SOCTO and most are associated with other thoracic injuries. Although patients with scapular fracture SOCTO and isolated scapular fracture have higher admission rates and ISS than nonscapular fracture patients, their hospital mortality is similar.

Review of Interventions and Radiation Exposure from Chest Computed Tomography in Children with Blunt Trauma

OBJECTIVE

To determine the radiation risk to a child undergoing trauma evaluation with chest computed tomography (CCT) for every clinically actionable injury identified.

STUDY DESIGN

This observational, cross-sectional study included all blunt trauma patients under 18 years of age undergoing CCT in a single urban emergency department. Via a retrospective chart review, therapeutic interventions done exclusively for chest injuries identified on CCT scan were identified. Effective radiation from each CCT was calculated and averaged and the dose required to diagnose 1 management-changing chest injury was determined.

RESULTS

Of 209 children undergoing CCT over a 19-month period, 168 were victims of blunt trauma. Ten required an intervention specifically for a chest injury identified on CCT (suggesting development of 1 malignancy per 37 actionable injures identified). None required an intervention for an injury exclusively noted on CCT, as all 10 actionable injuries were apparent via other modalities (radiograph, ultrasound examination, clinical examination).

CONCLUSION

Although 10 uniquely actionable injuries were identified on CCT, none were found only on CCT. Because CCTs rarely modified management, the amount of radiation administered per management change was sufficiently high to recommend reconsideration of current imaging practice in this single-center study.

Low Yield of Paired Head and Cervical Spine Computed Tomography in Blunt Trauma Evaluation

BACKGROUND

With increased computed tomography (CT) utilization, clinicians may simultaneously order head and neck CT scans, even when injury is suspected only in one region.

OBJECTIVE

We sought to determine: 1) the frequency of simultaneous ordering of a head CT scan when a neck CT scan is ordered; 2) the yields of simultaneously ordered head and neck CT scans for clinically significant injury (CSI); and 3) whether injury in one region is associated with a higher rate of injury in the other.

METHODS

This was a retrospective study of all adult patients who received neck CT scans (and simultaneously ordered head CT scans) as part of their blunt trauma evaluation at an urban level 1 trauma center in 2013. An expert panel determined CSI of head and neck injuries. We defined yield as number of patients with injury/number of patients who had a CT scan.

RESULTS

Of 3223 patients who met inclusion criteria, 2888 (89.6%) had simultaneously ordered head and neck CT scans. CT yield for CSI in both the head and neck was 0.5% (95% confidence interval [CI] 0.3-0.8%), and the yield for any injury in both the head and neck was 1.4% (95% CI 1.0-1.8%). The yield for CSI in one region was higher when CSI was seen in the other region.

CONCLUSIONS

The yield of CT for CSI in both the head and neck concomitantly is very low. When injury is seen in one region, there is higher likelihood of injury in the other. These findings argue against paired ordering of head and neck CT scans and suggest that CT scans should be ordered individually or when injury is detected in one region.

Clinical Judgment Is Not Reliable for Reducing Whole-body Computed Tomography Scanning after Isolated High-energy Blunt Trauma

Background

The purpose of this study was to test the diagnostic performance of clinical judgment for the prediction of a significant injury with whole-body computed tomography scanning after high-energy trauma.

Methods

The authors conducted an observational prospective study in a single level-I trauma center. Adult patients were included if they had an isolated high-energy injury. Senior trauma leaders were asked to make a clinical judgment regarding the likelihood of a significant injury before performance of a whole-body computed tomography scan. Clinical judgments were recorded using a probability diagnosis scale. The primary endpoint was the diagnosis of a serious-to-critical lesion on the whole-body computed tomography scan. Diagnostic performance was assessed using receiver operating characteristic analysis.

Results

Of the 354 included patients, 127 patients (36%) had at least one injury classified as abbreviated injury score greater than or equal to 3. The area under the receiver operating characteristic curve of the clinical judgment to predict a serious-to-critical lesion was 0.70 (95% CI, 0.64 to 0.75%). The sensitivity of the clinical judgment was 82% (95% CI, 74 to 88%), and the specificity was 49% (95% CI, 42 to 55%). No patient with a strict negative clinical examination had a severe lesion (n = 19 patients). The sensitivity of the clinical examination was 100% (95% CI, 97 to 100%) and its specificity was 8% (95% CI, 5 to 13%).

Conclusions

Clinical judgment alone is not sufficient to reduce whole-body computed tomography scan use. In patients with a strictly normal physical examination, whole-body computed tomography scanning might be avoided, but this result deserves additional study in larger and more diverse populations of trauma patients.

Rib Fracture Diagnosis in the Panscan Era

STUDY OBJECTIVE

With increased use of chest computed tomography (CT) in trauma evaluation, traditional teachings in regard to rib fracture morbidity and mortality may no longer be accurate. We seek to determine rates of rib fracture observed on chest CT only; admission and mortality of patients with isolated rib fractures, rib fractures observed on CT only, and first or second rib fractures; and first or second rib fracture-associated great vessel injury.

METHODS

We conducted a planned secondary analysis of 2 prospectively enrolled cohorts of the National Emergency X-Radiography Utilization Study chest studies, which evaluated patients with blunt trauma who were older than 14 years and received chest imaging in the emergency department. We defined rib fractures and other thoracic injuries according to CT reports and followed patients through their hospital course to determine outcomes.

RESULTS

Of 8,661 patients who had both chest radiograph and chest CT, 2,071 (23.9%) had rib fractures, and rib fractures were observed on chest CT only in 1,368 cases (66.1%). Rib fracture patients had higher admission rates (88.7% versus 45.8%; mean difference 42.9%; 95% confidence interval [CI] 41.4% to 44.4%) and mortality (5.6% versus 2.7%; mean difference 2.9%; 95% CI 1.8% to 4.0%) than patients without rib fracture. The mortality of patients with rib fracture observed on chest CT only was not statistically significantly different from that of patients with fractures also observed on chest radiograph (4.8% versus 5.7%; mean difference -0.9%; 95% CI -3.1% to 1.1%). Patients with first or second rib fractures had significantly higher mortality (7.4% versus 4.1%; mean difference 3.3%; 95% CI 0.2% to 7.1%) and prevalence of concomitant great vessel injury (2.8% versus 0.6%; mean difference 2.2%; 95% CI 0.6% to 4.9%) than patients with fractures of ribs 3 to 12, and the odds ratio of great vessel injury with first or second rib fracture was 4.4 (95% CI 1.8 to 10.4).

CONCLUSION

Under trauma imaging protocols that commonly incorporate chest CT, two thirds of rib fractures were observed on chest CT only. Patients with rib fractures had higher admission rates and mortality than those without rib fractures. First or second rib fractures were associated with significantly higher mortality and great vessel injury.

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.

Selective chest imaging for blunt trauma patients: The national emergency X-ray utilization studies (NEXUS-chest algorithm)

Chest imaging plays a prominent role in blunt trauma patient evaluation, but indiscriminate imaging is expensive, may delay care, and unnecessarily exposes patients to potentially harmful ionizing radiation. To improve diagnostic chest imaging utilization, we conducted 3 prospective multicenter studies over 12years to derive and validate decision instruments (DIs) to guide the use of chest x-ray (CXR) and chest computed tomography (CT). The first DI, NEXUS Chest x-ray, consists of seven criteria (Age >60years; rapid deceleration mechanism; chest pain; intoxication; altered mental status; distracting painful injury; and chest wall tenderness) and exhibits a sensitivity of 99.0% (95% confidence interval [CI] 98.2-99.4%) and a specificity of 13.3% (95% CI, 12.6%-14.0%) for detecting clinically significant injuries. We developed two NEXUS Chest CT DIs, which are both highly reliable in detecting clinically major injuries (sensitivity of 99.2%; 95% CI 95.4-100%). Designed primarily to focus on detecting major injuries, the NEXUS Chest CT-Major DI consists of six criteria (abnormal CXR; distracting injury; chest wall tenderness; sternal tenderness; thoracic spine tenderness; and scapular tenderness) and exhibits higher specificity (37.9%; 95% CI 35.8-40.1%). Designed to reliability detect both major and minor injuries (sensitivity 95.4%; 95% CI 93.6-96.9%) with resulting lower specificity (25.5%; 95% CI 23.5-27.5%), the NEXUS CT-All rule consists of seven elements (the six NEXUS CT-Major criteria plus rapid deceleration mechanism). The purpose of this review is to synthesize the three DIs into a novel, cohesive summary algorithm with practical implementation recommendations to guide selective chest imaging in adult blunt trauma patients.

The clinical benefit of a follow-up thoracic computed tomography scan regarding parenchymal lung injury and acute respiratory distress syndrome in polytraumatized patients

PURPOSE

To evaluate the increase of parenchymal lung injury (PLI) volume between the initial and a follow-up computed tomography (CT) scan and to ascertain which of the 2 scans was more appropriate to predict acute respiratory distress syndrome (ARDS).

MATERIAL AND METHODS

From 2011 to 2015, polytraumatized patients (≥18 years; ISS ≥ 16) directly admitted to our level I trauma center were included in our prospective study if a follow-up CT scan was possible 24 to 48 hours after the trauma. The PLI volume was measured using volumetric analysis. Statistical calculations were performed to identify patients at risk for ARDS.

RESULTS

One hundred thirty patients (mean age, 41.3 years; mean ISS, 31.9) met the inclusion criteria. Median relative PLI volume was higher in the follow-up than in the initial CTs (9.65% vs 4.84%; P = .001). The ARDS developed in 42 patients (32.3%). Their initial PLI volume was higher compared with those without ARDS (11.23% vs 2.14%; P < .0001). The ARDS incidence increased with increasing initial PLI volume. Receiver operating characteristic statistics identified initial (area under the curve = 0.753) and follow-up relative PLI volume as a predictor for ARDS (area under the curve = 0.725).

CONCLUSIONS

The CT scans performed directly after admission are sufficient to define patients at risk for ARDS. Therefore, solely the incidence of PLI does not justify a routine follow-up CT scan.

Prevalence and Diagnostic Performance of Isolated and Combined NEXUS Chest CT Decision Criteria

OBJECTIVES

The use of chest computed tomography (CT) to evaluate emergency department patients with adult blunt trauma is rising. The NEXUS Chest CT decision instruments are highly sensitive identifiers of adult blunt trauma patients with thoracic injuries. However, many patients without injury exhibit one of more of the criteria so cannot be classified "low risk." We sought to determine screening performance of both individual and combined NEXUS Chest CT criteria as predictors of thoracic injury to inform chest CT imaging decisions in "non-low-risk" patients.

METHODS

This was a secondary analysis of data on patients in the derivation and validation cohorts of the prospective, observational NEXUS Chest CT study, performed September 2011 to May 2014 in 11 Level I trauma centers. Institutional review board approval was obtained at all study sites. Adult blunt trauma patients receiving chest CT were included. The primary outcome was injury and major clinical injury prevalence and screening performance in patients with combinations of one, two, or three of seven individual NEXUS Chest CT criteria.

RESULTS

Across the 11 study sites, rates of chest CT performance ranged from 15.5% to 77.2% (median = 43.6%). We found injuries in 1,493/5,169 patients (28.9%) who had chest CT; 269 patients (5.2%) had major clinical injury (e.g., pneumothorax requiring chest tube). With sensitivity of 73.7 (95% confidence interval [CI] = 68.1 to 78.6) and specificity of 83.9 (95% CI = 83.6 to 84.2) for major clinical injury, abnormal chest-x-ray (CXR) was the single most important screening criterion. When patients had only abnormal CXR, injury and major clinical injury prevalences were 60.7% (95% CI = 52.2% to 68.6%) and 12.9% (95% CI = 8.3% to 19.4%), respectively. Injury and major clinical injury prevalences when any other single criterion alone (other than abnormal CXR) was present were 16.8% (95% CI = 15.2% to 18.6%) and 1.1% (95% CI = 0.1% to 1.8%), respectively. Injury and major clinical injury prevalences among patients when two and three criteria (not abnormal CXR) were present were 25.5% (95% CI = 23.1% to 28.0%) and 3.2% (95% CI = 2.3% to 4.4%) and 34.9% (95% CI = 31.0% to 39.0%) and 2.7% (95% CI = 1.6% to 4.5%), respectively.

CONCLUSIONS

We recommend that clinicians check for the six clinical NEXUS Chest CT criteria and review the CXR (if obtained). If patients have one clinical criterion (other than abnormal CXR), they will have a very low risk of clinically major injury. We recommend that clinicians discuss the potential risks and benefit of chest CT in these cases. The risks of injury and major clinical injury rise incrementally with more criteria, rendering the risk/benefit ratio toward performing CT in most cases. If the patient has an abnormal CXR, the risks of major clinical injury and minor injury are considerably higher than with the other criteria-chest CT may be indicated in cases requiring greater anatomic detail and injury characterization.

Pulmonary contusion in the pan-scan era

BACKGROUND

Although pulmonary contusion (PC) is traditionally considered a major injury requiring intensive monitoring, more frequent detection by chest CT in blunt trauma evaluation may diagnose clinically irrelevant PC.

OBJECTIVES

We sought to determine (1) the frequency of PC diagnosis by chest CT versus chest X-ray (CXR), (2) the frequency of PC-associated thoracic injuries, and (3) PC patient clinical outcomes (mortality, length of stay [LOS], and need for mechanical ventilation), considering patients with PC seen on chest CT only (SOCTO) and isolated PC (PC without other thoracic injury).

METHODS

Focusing primarily on patients who had both CXR and chest CT, we conducted a pre-planned analysis of two prospectively enrolled cohorts with the following inclusion criteria: age >14 years, blunt trauma within 24h of emergency department presentation, and receiving CXR or chest CT during trauma evaluation. We defined PC and other thoracic injuries according to CT reports and followed patients through their hospital course to determine clinical outcomes.

RESULTS

Of 21,382 enrolled subjects, 8661 (40.5%) had both CXR and chest CT and 1012 (11.7%) of these had PC, making it the second most common injury after rib fracture. PC was SOCTO in 739 (73.0%). Most (73.5%) PC patients had other thoracic injury. PC patients had higher admission rates (91.9% versus 61.7%; mean difference 30.2%; 95% confidence interval [CI] 28.1-32.1%) and mortality (4.7% versus 2.0%: mean difference 2.8%; 95% CI 1.6-4.3%) than non-PC patients, but mortality was restricted to patients with other injuries (injury severity scores>10). Patients with PC SOCTO had low rates of associated mechanical ventilation (4.6%) and patients with isolated PC SOCTO had low mortality (2.6%), comparable to that of patients without PC.

CONCLUSIONS

PC is commonly diagnosed under current blunt trauma imaging protocols and most PC are SOCTO with other thoracic injury. Given that they are associated with low mortality and uncommon need for mechanical ventilation, isolated PC and PC SOCTO may be of limited clinical significance.

Transparency in reporting observational studies: reflections after a year

The PLOS Medicine Editors take stock of changes in the reporting of observational studies following our new transparency guidelines from August 2014.

New clinical decision instruments can and should reduce radiation exposure

In this Perspective linked to Rodriguez and colleagues, Emmanuel Lagarde discusses the importance of decision instruments that can help physicians avoid subjecting patients to radiation exposure from unnecessary CT scans.