Wireless point-of-care ultrasound in a multiplace hyperbaric chamber.

Background: Electronic devices remain highly restricted from use during hyperbaric oxygen (HBO2) treatment due to risk of fire in a pressurized, oxygen-rich environment. Over recent decades, point-of- care ultrasound (POCUS) has established utility in most clinical environments except hyperbaric chambers, where only heavily modified POCUS devices have been used. This study evaluated proof of concept, safety, and performance of a wireless off-the-shelf handheld POCUS device in the hyperbaric environment. Materials and Methods: The GE Vscan Air was initially tested in a Class C chamber with 100% nitrogen up to 4.0 ATA and monitored. Second, the Vscan Air was paired with an encased Apple iPad, tested previously for hyperbaric use, and both were pressurized to 2.4 ATA in a Class A chamber (21% oxygen) and evaluated. Similarly, it was then tested at 2.8 ATA and also paired wirelessly with an iPad outside the chamber. Device temperature, image quality, functionality, and wireless connection were tested continuously. Results: The GE Vscan Air automatically shut off due to power button depression during initial compression; thus the power button was punctured with an 18-gauge needle to equalize gas pressure. Thereafter, the system performed well throughout all tests without degradation in function or image quality. The device did not overheat nor reach temperatures concerning for fire hazard. Further, wireless connection to out-of-chamber devices was maintained. Conclusions: Our results suggest that the GE Vscan Air can be used with minor modification in a multi- place hyperbaric chamber. Wireless functionality allows for pairing with a screen and device outside the chamber.

Genicular nerve block for emergency department patient: a successful management of subacute osteoarthritic knee pain.

The genicular nerve block (GNB) performed under ultrasound is a common procedure in the perioperative and outpatient setting for the treatment of surgical knee pain and osteoarthritis. It provides motor-sparing analgesia to the knee, making it a potential alternative to other modes of pain management in the emergency department (ED). We present an elderly woman with acute-on-chronic osteoarthritic knee pain which was relieved for a week after a GNB during her ED visit. In patients with knee pain, the ultrasound guided GNB has the potential to provide short-term analgesia for patients with pain refractory to other modes of analgesia. The GNB shows promise as a reliable contribution to a multimodal approach to pain management in the ED setting.

Comparison of Radiographic, Ultrasound, and Magnetic Resonance Imaging for the Detection of Retained Stingray Barb: A Cadaveric Study.

INTRODUCTION: Stingray envenomations are a common marine animal injury for which it is important to identify and remove retained barbs to prevent secondary infection. The optimal imaging modality in stingray foreign body detection is not well characterized in the existing literature. In this study, we compared the accuracy of plain radiography, ultrasound, and magnetic resonance imaging (MRI) in detecting stingray barbs in the human foot and ankle. METHODS: This cadaveric study included a 1:1 randomization to the presence or absence of barbs in 24 sample injuries of human cadaveric foot and ankle specimens. Physicians trained in emergency medicine and radiology performed ultrasound examinations on each specimen and interpreted the presence or absence of a barb. Participants also interpreted x-ray images in the same manner. MRI scans were separately interpreted by a musculoskeletal radiology attending. Data were analyzed using McNemar's test. RESULTS: The 19 participants included 14 (74%) trained in emergency medicine and 5 (26%) trained in radiology. Forty-seven percent were residents, 42% faculty, and 11% fellows. X-ray was associated with the highest sensitivity of 94% for the identification of a retained barb, followed by MRI (83%) and ultrasound (70%). MRI was associated with the highest specificity of 100%, followed by x-ray (98%) and ultrasound (73%). CONCLUSIONS: Retained stingray barbs can lead to secondary infection after envenomation. In human cadaveric specimens, x-ray demonstrated the highest sensitivity, MRI demonstrated the highest specificity, and ultrasound demonstrated lower sensitivity and specificity.

Emergency physician stressors, concerns, and behavioral changes during COVID-19: A longitudinal study.

OBJECTIVES: The objective was to provide a longitudinal assessment of anxiety levels and work and home concerns of U.S. emergency physicians during the COVID-19 pandemic. METHODS: We performed a longitudinal, cross-sectional email survey of clinically active emergency physicians (attending, fellow, and resident) at seven academic emergency departments. Follow-up surveys were sent 4 to 6 weeks after the initial survey and assessed the following: COVID-19 patient exposure, availability of COVID-19 testing, levels of home and workplace anxiety/stress, changes in behaviors, and performance on a primary care posttraumatic stress disorder screen (PC-PTSD-5). Logistic regression explored factors associated with a high PC-PTSD-5 scale score (≥3), indicating increased risk for PTSD. RESULTS: Of the 426 surveyed initial respondents, 262 (61.5%) completed the follow-up survey. While 97.3% (255/262) reported treating suspected COVID-19 patients, most physicians (162/262, 61.8%) had not received testing themselves. In follow-up, respondents were most concerned about the relaxing of social distancing leading to a second wave (median score = 6, IQR = 4-7). Physicians reported a consistently high ability to order COVID-19 tests for patients (median score = 6, IQR = 5-7) and access to personal protective equipment (median score = 6, IQR = 5-6). Women physicians were more likely to score ≥ 3 than men on the PC-PTSD-5 screener on the initial survey (43.3% vs. 22.5%; Δ 20.8%, 95% confidence interval [CI] = 9.3% to 31.5%), and despite decreases in overall proportions, this discrepancy remained in follow-up (34.7% vs. 16.8%; Δ 17.9%, 95% CI = 7.1% to 28.1%). In examining the relationship between demographics, living situations, and institution location on having a PC-PTSD-5 score ≥ 3, only female sex was associated with a PC-PTSD-5 score ≥ 3 (adjusted odds ratio = 2.48, 95% CI = 1.28 to 4.79). CONCLUSIONS: While exposure to suspected COVID-19 patients was nearly universal, stress levels in emergency physicians decreased with time. At both initial and follow-up assessments, women were more likely to test positive on the PC-PTSD-5 screener compared to men.

Academic Emergency Medicine Physicians' Anxiety Levels, Stressors, and Potential Stress Mitigation Measures During the Acceleration Phase of the COVID-19 Pandemic.

OBJECTIVE: The objective was to assess anxiety and burnout levels, home life changes, and measures to relieve stress of U.S. academic emergency medicine (EM) physicians during the COVID-19 pandemic acceleration phase. METHODS: We sent a cross-sectional e-mail survey to all EM physicians at seven academic emergency departments. The survey incorporated items from validated stress scales and assessed perceptions and key elements in the following domains: numbers of suspected COVID-19 patients, availability of diagnostic testing, levels of home and workplace anxiety, severity of work burnout, identification of stressors, changes in home behaviors, and measures to decrease provider anxiety. RESULTS: A total of 426 (56.7%) EM physicians responded. On a scale of 1 to 7 (1 = not at all, 4 = somewhat, and 7 = extremely), the median (interquartile range) reported effect of the pandemic on both work and home stress levels was 5 (4-6). Reported levels of emotional exhaustion/burnout increased from a prepandemic median (IQR) of 3 (2-4) to since the pandemic started a median of 4 (3-6), with a difference in medians of 1.8 (95% confidence interval = 1.7 to 1.9). Most physicians (90.8%) reported changing their behavior toward family and friends, especially by decreasing signs of affection (76.8%). The most commonly cited measures cited to alleviate stress/anxiety were increasing personal protective equipment (PPE) availability, offering rapid COVID-19 testing at physician discretion, providing clearer communication about COVID-19 protocol changes, and assuring that physicians can take leave for care of family and self. CONCLUSIONS: During the acceleration phase, the COVID-19 pandemic has induced substantial workplace and home anxiety in academic EM physicians, and their exposure during work has had a major impact on their home lives. Measures cited to decrease stress include enhanced availability of PPE, rapid turnaround testing at provider discretion, and clear communication about COVID-19 protocol changes.

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.

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.

Interpretation Accuracy and Interrater Agreement of Pediatric Skin and Soft Tissue Point-of-Care Ultrasound Images among Residents and Faculty.

BACKGROUND: Point-of-care ultrasound (POCUS) is commonly used to facilitate care in the emergency department. Acquired images are often reviewed by local experts for educational and quality assurance purposes. However, no published study has examined the accuracy and reliability of POCUS image interpretation by multiple reviewers. OBJECTIVES: We studied the accuracy and interrater agreement among expert and trainee reviewers of prerecorded pediatric skin and soft tissue (SST) POCUS images. METHODS: POCUS faculty and emergency medicine (EM) residents blindly reviewed deidentified pediatric SST POCUS images and indicated whether a drainable fluid collection was present, absent, or indeterminate. This was then compared with the gold standard based on discharge diagnoses and telephone follow-up. Images rated as indeterminate were excluded from the initial analysis. Sensitivity analysis assuming indeterminate answers were inaccurate was subsequently conducted. RESULTS: In phase 1, 6 pediatric EM POCUS directors reviewed 168 images. The overall accuracy was 79.7% (range 66.1-86.0%). The mean Cohen's kappa was 0.58 (range 0.24-0.84). Sensitivity analysis yielded an overall accuracy of 71.3% (range 56.5-76.9%) and a Cohen's kappa of 0.43 (range 0.20-0.59). In phase 2, 6 general EM POCUS faculty and 20 EM residents reviewed 120 images. The overall accuracy among residents was 72.2% (range 51.4-84.7%) and among faculty was 83.6% (range 77.9-88.8%). Sensitivity analysis yielded an overall resident accuracy of 63.0% (range 49.5-80.7) and an overall faculty accuracy of 73.9% (range 67.0-79.8%). Fleiss' kappa was 0.322 for residents and 0.461 for faculty. CONCLUSIONS: We found moderate accuracy and fair to good interrater agreement among POCUS faculty and EM residents reviewing pediatric SST POCUS images.

Pneumothorax and Hemothorax in the Era of Frequent Chest Computed Tomography for the Evaluation of Adult Patients With Blunt Trauma.

STUDY OBJECTIVE: Although traditional teachings in regard to pneumothorax and hemothorax generally recommend chest tube placement and hospital admission, the increasing use of chest computed tomography (CT) in blunt trauma evaluation may detect more minor pneumothorax and hemothorax that might indicate a need to modify these traditional practices. We determine the incidence of pneumothorax and hemothorax observed on CT only and the incidence of isolated pneumothorax and hemothorax (pneumothorax and hemothorax occurring without other thoracic injuries), and describe the clinical implications of these injuries. METHODS: This was a planned secondary analysis of 2 prospective, observational studies of adult patients with blunt trauma, NEXUS Chest (January 2009 to December 2012) and NEXUS Chest CT (August 2011 to May 2014), set in 10 Level I US trauma centers. Participants' inclusion criteria were older than 14 years, presentation to the emergency department (ED) within 6 hours of blunt trauma, and receipt of chest imaging (chest radiograph, chest CT, or both) during their ED evaluation. Exposure(s) (for observational studies) were that patients had trauma and chest imaging. Primary measures and outcomes included the incidence of pneumothorax and hemothorax observed on CT only versus on both chest radiograph and chest CT, the incidence of isolated pneumothorax and hemothorax (pneumothorax and hemothorax occurring without other thoracic injuries), and admission rates, hospital length of stay, mortality, and frequency of chest tube placement for these injuries. RESULTS: Of 21,382 enrolled subjects, 1,064 (5%) had a pneumothorax and 384 (1.8%) had a hemothorax. Of the 8,661 patients who received both a chest radiograph and a chest CT, 910 (10.5%) had a pneumothorax, with 609 (67%) observed on CT only; 319 (3.7%) had a hemothorax, with 254 (80%) observed on CT only. Of 1,117 patients with pneumothorax, hemothorax, or both, 108 (10%) had isolated pneumothorax or hemothorax. Patients with pneumothorax observed on CT only had a lower chest tube placement rate (30% versus 65%; difference in proportions [Δ] -35%; 95% confidence interval [CI] -28% to 42%), admission rate (94% versus 99%; Δ 5%; 95% CI 3% to 8%), and median length of stay (5 versus 6 days; difference 1 day; 95% CI 0 to 2 days) but similar mortality compared with patients with pneumothorax observed on chest radiograph and CT. Patients with hemothorax observed on CT had only a lower chest tube placement rate (49% versus 68%; Δ -19%; 95% CI -31% to -5%) but similar admission rate, mortality, and median length of stay compared with patients with hemothorax observed on chest radiograph and CT. Compared with patients with other thoracic injury, those with isolated pneumothorax or hemothorax had a lower chest tube placement rate (20% versus 43%; Δ -22%; 95% CI -30% to -13%), median length of stay (4 versus 5 days; difference -1 day; 95% CI -3 to 1 days), and admission rate (44% versus 97%; Δ -53%; 95% CI -62% to -43%), with an admission rate comparable to that of patients without pneumothorax or hemothorax (49%). CONCLUSION: Under current imaging protocols for adult blunt trauma evaluation, most pneumothoraces and hemothoraces are observed on CT only and few occur as isolated thoracic injury. The clinical implications (admission rates and frequency of chest tube placement) of pneumothorax and hemothorax observed on CT only and isolated pneumothorax or hemothorax are lower than those of patients with pneumothorax and hemothorax observed on chest radiograph and CT and of those who have other thoracic injury, respectively.

Spontaneous Diaphragmatic Hernia.

A spontaneous diaphragmatic hernia (SDH) occurs when intra-abdominal contents extend into the thoracic cavity through a defect in the diaphragm after a sudden increase in intra-abdominal pressure. SDH is one of the rarest surgical emergencies with less than 30 reported cases in the literature.1,2 In our case a 94-year-old female presented to the emergency department in respiratory distress with unilateral breath sounds and was diagnosed with a SDH. The only treatment option for a SDH is surgical.3,11 However, nasogastric tube decompression of the gastrointestinal tract and supplemental oxygen can be used to alleviate symptoms until definitive operative management is performed.

Use of Point-of-Care Ultrasound to Guide Pediatric Gastrostomy Tube Replacement in the Emergency Department.

The presentation of a pediatric patient to the emergency department for a malfunctioning or dislodged gastrostomy tube (G-tube) is not uncommon. As such, these tubes are often replaced at the bedside. Improper placement can result in a number of complications, including perforation, fistula tract formation, peritonitis, and sepsis. The current criterion standard method to confirm proper G-tube placement is contrast-enhanced radiography. However, point-of-care ultrasound may be an alternative method to guide and confirm pediatric G-tube replacement in the emergency department. We report a series of cases on this novel point-of-care ultrasound application.

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.

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.

Prevalence of Chest Injury With the Presence of NEXUS Chest Criteria: Data to Inform Shared Decisionmaking About Imaging Use.

STUDY OBJECTIVE: The NEXUS chest decision instrument identifies a very-low-risk population of patients with blunt trauma for whom chest imaging can be avoided. However, it requires that all 7 National Emergency X-Ray Utilization Study (NEXUS) chest criteria be absent. To inform patient and physician shared decisionmaking about imaging, we describe the test characteristics of individual criteria of the NEXUS chest decision instrument and provide the prevalence of injuries when 1, 2, or 3 of the 7 criteria are present. METHODS: We conducted this secondary analysis of 2 prospectively collected cohorts of patients with blunt trauma who were older than 14 years and enrolled in NEXUS chest studies between December 2009 and January 2012. Physicians at 9 US Level I trauma centers recorded the presence or absence of the 7 NEXUS chest criteria. We calculated test characteristics of each criterion and combinations of criteria for the outcome measures of major clinical injuries and thoracic injury observed on chest imaging. RESULTS: We enrolled 21,382 patients, of whom 992 (4.6%) had major clinical injuries and 3,135 (14.7%) had thoracic injuries observed on chest imaging. Sensitivities of individual test characteristics ranged from 15% to 56% for major clinical injury and 14% to 53% for thoracic injury observed on chest imaging, with specificities varying from 71% to 84% for major clinical injury and 67% to 84% for thoracic injury observed on chest imaging. Individual criteria were associated with a prevalence of major clinical injury between 1.9% and 3.8% and of thoracic injury observed on chest imaging between 5.3% and 11.5%. CONCLUSION: Patients with isolated NEXUS chest criteria have low rates of major clinical injury. The risk of major clinical injury for patients with 2 or 3 factors range from 1.7% to 16.6%, depending on the combination of criteria. Criteria-specific risks could be used to inform shared decisionmaking about the need for imaging by patients and their physicians.

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.

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

BACKGROUND: Unnecessary diagnostic imaging leads to higher costs, longer emergency department stays, and increased patient exposure to ionizing radiation. We sought to prospectively derive and validate two decision instruments (DIs) for selective chest computed tomography (CT) in adult blunt trauma patients. METHODS AND FINDINGS: From September 2011 to May 2014, we prospectively enrolled blunt trauma patients over 14 y of age presenting to eight US, urban level 1 trauma centers in this observational study. During the derivation phase, physicians recorded the presence or absence of 14 clinical criteria before viewing chest imaging results. We determined injury outcomes by CT radiology readings and categorized injuries as major or minor according to an expert-panel-derived clinical classification scheme. We then employed recursive partitioning to derive two DIs: Chest CT-All maximized sensitivity for all injuries, and Chest CT-Major maximized sensitivity for only major thoracic injuries (while increasing specificity). In the validation phase, we employed similar methodology to prospectively test the performance of both DIs. We enrolled 11,477 patients-6,002 patients in the derivation phase and 5,475 patients in the validation phase. The derived Chest CT-All DI consisted of (1) abnormal chest X-ray, (2) rapid deceleration mechanism, (3) distracting injury, (4) chest wall tenderness, (5) sternal tenderness, (6) thoracic spine tenderness, and (7) scapular tenderness. The Chest CT-Major DI had the same criteria without rapid deceleration mechanism. In the validation phase, Chest CT-All had a sensitivity of 99.2% (95% CI 95.4%-100%), a specificity of 20.8% (95% CI 19.2%-22.4%), and a negative predictive value (NPV) of 99.8% (95% CI 98.9%-100%) for major injury, and a sensitivity of 95.4% (95% CI 93.6%-96.9%), a specificity of 25.5% (95% CI 23.5%-27.5%), and a NPV of 93.9% (95% CI 91.5%-95.8%) for either major or minor injury. Chest CT-Major had a sensitivity of 99.2% (95% CI 95.4%-100%), a specificity of 31.7% (95% CI 29.9%-33.5%), and a NPV of 99.9% (95% CI 99.3%-100%) for major injury and a sensitivity of 90.7% (95% CI 88.3%-92.8%), a specificity of 37.9% (95% CI 35.8%-40.1%), and a NPV of 91.8% (95% CI 89.7%-93.6%) for either major or minor injury. Regarding the limitations of our work, some clinicians may disagree with our injury classification and sensitivity thresholds for injury detection. CONCLUSIONS: We prospectively derived and validated two DIs (Chest CT-All and Chest CT-Major) that identify blunt trauma patients with clinically significant thoracic injuries with high sensitivity, allowing for a safe reduction of approximately 25%-37% of unnecessary chest CTs. Trauma evaluation protocols that incorporate these DIs may decrease unnecessary costs and radiation exposure in the disproportionately young trauma population.

Prevalence and Clinical Import of Thoracic Injury Identified by Chest Computed Tomography but Not Chest Radiography in Blunt Trauma: Multicenter Prospective Cohort Study.

STUDY OBJECTIVE: Chest computed tomography (CT) diagnoses more injuries than chest radiography, so-called occult injuries. Wide availability of chest CT has driven substantial increase in emergency department use, although the incidence and clinical significance of chest CT findings have not been fully described. We determine the frequency, severity, and clinical import of occult injury, as determined by changes in management. These data will better inform clinical decisions, need for chest CT, and odds of intervention. METHODS: Our sample included prospective data (2009 to 2013) on 5,912 patients at 10 Level I trauma center EDs with both chest radiography and chest CT at physician discretion. These patients were 40.6% of 14,553 enrolled in the parent study who had either chest radiography or chest CT. Occult injuries were pneumothorax, hemothorax, sternal or greater than 2 rib fractures, pulmonary contusion, thoracic spine or scapula fracture, and diaphragm or great vessel injury found on chest CT but not on preceding chest radiography. A priori, we categorized thoracic injuries as major (having invasive procedures), minor (observation or inpatient pain control >24 hours), or of no clinical significance. Primary outcome was prevalence and proportion of occult injury with major interventions of chest tube, mechanical ventilation, or surgery. Secondary outcome was minor interventions of admission rate or observation hours because of occult injury. RESULTS: Two thousand forty-eight patients (34.6%) had chest injury on chest radiography or chest CT, whereas 1,454 of these patients (71.0%, 24.6% of all patients) had occult injury. Of these, in 954 patients (46.6% of injured, 16.1% of total), chest CT found injuries not observed on immediately preceding chest radiography. In 500 more patients (24.4% of injured patients, 8.5% of all patients), chest radiography found some injury, but chest CT found occult injury. Chest radiography found all injuries in only 29.0% of injured patients. Two hundred and two patients with occult injury (of 1,454, 13.9%) had major interventions, 343 of 1,454 (23.6%) had minor interventions, and 909 (62.5%) had no intervention. Patients with occult injury included 514 with pulmonary contusions (of 682 total, 75.4% occult), 405 with pneumothorax (of 597 total, 67.8% occult), 184 with hemothorax (of 230 total, 80.0% occult), those with greater than 2 rib fractures (n=672/1,120, 60.0% occult) or sternal fracture (n=269/281, 95.7% occult), 12 with great vessel injury (of 18 total, 66.7% occult), 5 with diaphragm injury (of 6, 83.3% occult), and 537 with multiple occult injuries. Interventions for patients with occult injury included mechanical ventilation for 31 of 514 patients with pulmonary contusion (6.0%), chest tube for 118 of 405 patients with pneumothorax (29.1%), and 75 of 184 patients with hemothorax (40.8%). Inpatient pain control or observation greater than 24 hours was conducted for 183 of 672 patients with rib fractures (27.2%) and 79 of 269 with sternal fractures (29.4%). Three of 12 (25%) patients with occult great vessel injuries had surgery. Repeated imaging was conducted for 50.6% of patients with occult injury (88.1% chest radiography, 11.9% chest CT, 7.5% both). For patients with occult injury, 90.9% (1,321/1,454) were admitted, with 9.1% observed in the ED for median 6.9 hours. Forty-four percent of observed patients were then admitted (4.0% of patients with occult injury). CONCLUSION: In a more seriously injured subset of patients with blunt trauma who had both chest radiography and chest CT, occult injuries were found by chest CT in 71% of those with thoracic injuries and one fourth of all those with blunt chest trauma. More than one third of occult injury had intervention (37.5%). Chest tubes composed 76.2% of occult injury major interventions, with observation or inpatient pain control greater than 24 hours in 32.4% of occult fractures. Only 1 in 20 patients with occult injury was discharged home from the ED. For these patients with blunt trauma, chest CT is useful to identify otherwise occult injuries.

Sternal fracture in the age of pan-scan.

STUDY OBJECTIVE: Widespread chest CT use in trauma evaluation may increase the diagnosis of minor sternal fracture (SF), making former teaching about SF obsolete. We sought to determine: (1) the frequency with which SF patients are diagnosed by CXR versus chest CT under current imaging protocols, (2) the frequency of surgical procedures related to SF diagnosis, (3) SF patient mortality and hospital length of stay comparing patients with isolated sternal fracture (ISF) and sternal fracture with other thoracic injury (SFOTI), and (4) the frequency and yield of cardiac contusion (CC) workups in SF patients. METHODS: We analyzed charts and data of all SF patients enrolled from January 2009 to May 2013 in the NEXUS Chest and NEXUS Chest CT studies, two multi-centre observational cohorts of blunt trauma patients who received chest imaging for trauma evaluation. RESULTS: Of the 14,553 patients in the NEXUS Chest and Chest CT cohorts, 292 (2.0%) were diagnosed with SF, and 94% of SF were visible on chest CT only. Only one patient (0.4%) had a surgical procedure related to SF diagnosis. Cardiac contusion was diagnosed in 7 (2.4%) of SF patients. SF patient mortality was low (3.8%) and not significantly different than the mortality of patients without SF (3.1%) [mean difference 0.7%; 95% confidence interval (CI) -1.0 to 3.5%]. Only 2 SF patient deaths (0.7%) were attributed to a cardiac cause. SFOTI patients had longer hospital stays but similar mortality to patients with ISF (mean difference 0.8%; 95% CI -4.7% to 12.0). CONCLUSIONS: Most SF are seen on CT only and the vast majority are clinically insignificant with no change in treatment and low associated mortality. Workup for CC in SF patients is a low-yield practice. SF diagnostic and management guidelines should be updated to reflect modern CT-driven trauma evaluation protocols.

Diagnostic yields, charges, and radiation dose of chest imaging in blunt trauma evaluations.

BACKGROUND: Chest radiography (CXR) is the most common imaging in adult blunt trauma patient evaluation. Knowledge of the yields, attendant costs, and radiation doses delivered may guide effective chest imaging utilization. OBJECTIVES: The objectives were to determine the diagnostic yields of blunt trauma chest imaging (CXR and chest computed tomography [CT]), to estimate charges and radiation exposure per injury identified, and to delineate assessment points in blunt trauma evaluation at which decision instruments for selective chest imaging would have the greatest effect. METHODS: From December 2009 to January 2012, we enrolled patients older than 14 years who received CXR during blunt trauma evaluations at nine U.S. Level I trauma centers in this prospective, observational study. Thoracic injury seen on chest imaging and clinical significance of the injury were defined by a trauma expert panel. Yields of imaging were calculated, as well as mean charges and effective radiation dose (ERD) per injury. RESULTS: Of 9,905 enrolled patients, 55.4% had CXR alone, 42.0% had both CXR and CT, and 2.6% had CT alone. The yields for detecting thoracic injury were CXR 8.4% (95% confidence intervals [CIs]) = 7.8% to 8.9%), chest CT 28.8% (95% CI = 27.5% to 30.2%), and chest CT after normal CXR 15.0% (95% CI = 13.9% to 16.2%). The mean charges and ERD (millisievert [mSv]) per injury diagnosis of CXR, chest CT, and chest CT after normal CXR were $3,845 (0.24 mSv), $10,597 (30.9 mSv), and $20,347 (59.3 mSv), respectively. The mean charges and ERD per clinically major thoracic injury diagnosis on chest CT after normal CXR were $203,467 and 593 mSv. CONCLUSIONS: Despite greater diagnostic yield, chest CT entails substantially higher charges and radiation dose per injury diagnosed, especially when performed after a normal CXR. Selective chest imaging decision instruments should identify patients who require no chest imaging and patients who may benefit from chest CT after a normal CXR.