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

Traumatic pulmonary pseudocysts after blunt chest trauma: Prevalence, mechanisms of injury, and computed tomography findings

BACKGROUND

Traumatic pulmonary pseudocyst (TPP) is a rare complication of blunt chest trauma and closely related with severe injury. However, it has been poorly documented. We present a retrospective review of TPP cases treated at our hospital.

METHODS

The medical records and chest computed tomography scans of patients with TPP treated from January 2010 to December 2013 were retrospectively studied.

RESULTS

A total of 978 patients underwent chest computed tomography for blunt chest trauma during the study period, and 81 (8.3%) had a total of 150 TPPs. The most common mechanism of injury was being struck by a motorized vehicle (n = 25, 30.9%). The mean (SD) Injury Severity Score (ISS) of the 81 patients was 33.2 (11.4). The prevalence of TPP was higher in younger patients (p = 0.011), but the total number of fractured ribs was significantly lower (p = 0.001). In a subgroup analysis performed according to pseudocyst location, the intraparenchymal group had more severe injuries than the subpleural group (ISS, 23.3 vs. 32.4, p < 0.001; chest Abbreviated Injury Scale [AIS] score, 3.4 vs. 4.0, p < 0.001; number of associated injuries, 2.9 vs. 4.0, p = 0.001). By multivariate analysis, ISS, age, and number of associated injuries were significantly different in these two groups (p = 0.038, p = 0.006, and p = 0.045, respectively).

CONCLUSION

The prevalence of TPP among cases of blunt chest trauma was 8.3% and was higher in those struck by a vehicle and younger patients. Intraparenchymal pseudocyst was found to be related to more severe injuries. TPP was a self-limiting condition that does not require specific treatment.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level IV.

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.

Routine Chest Computed Tomography and Patient Outcome in Blunt Trauma

Background:

Computerized Tomography (CT) scan is gaining more importance in the initial evaluation of patients with multiple trauma, but its effect on the outcome is still unclear. Until now, no prospective randomized trial has been performed to define the role of routine chest CT in patients with blunt trauma.

Objectives:

In view of the considerable radiation exposure and the high costs of CT scan, the aim of this study was to assess the effects of performing the routine chest CT on the outcome as well as complications in patients with blunt trauma.

Patients and Methods:

After approval by the ethics board committee, 100 hemodynamically stable patients with high-energy blunt trauma were randomly divided into two groups. For group one (control group), only chest X-ray was requested and further diagnostic work-up was performed by the decision of the trauma team. For group two, a chest X-ray was ordered followed by a chest CT, even if the chest X-ray was normal. Injury severity, total hospitalization time, Intensive Care Unit (ICU) admission time, duration of mechanical ventilation and complications were recorded. Data were evaluated using t-test, Man-Whitney and chi-squared test.

Results:

No significant differences were found regarding the demographic data such as age, injury severity and Glasgow Coma Scale (GCS). Thirty-eight percent additional findings were seen in chest CT in 26% of the patients of the group undergoing routine chest CT, leading to 8% change in management. The mean of in-hospital stay showed no significant difference in both groups with a P value of 0.098. In addition, the mean ICU stay and ventilation time revealed no significant differences (P values = 0.102 and 0.576, respectively). Mortality rate and complications were similar in both groups.

Conclusions:

Performing the routine chest CT in high-energy blunt trauma patients (with a mean injury severity of 9), although leading to the diagnosis of some occult injuries, has no impact on the outcome and does not decrease the in-hospital stay and ICU admission time. It seems that performing the routine chest CT in these patients may lead to overtreatment of nonsignificant injuries. The decision about performing routine CT scan in a trauma center should be made cautiously, considering the detriments and benefits.

Sharp penetrating wounds: spectrum of imaging findings and legal aspects in the emergency setting

The main cause of severe civilian trauma is not the same all over the world; while in Europe the majority of cases are due to blunt traumatic injury, in the United States, penetrating gunshot wounds are the most common. Penetrating wounds can be classified into two different entities: gunshot wounds, or more technically ballistic traumas, and sharp penetrating traumas, also identifiable with non-ballistic traumas. Sharp penetrating injuries are mainly caused by sharp pointed objects such as spears, nails, daggers, knives, and arrows. The type of injuries caused by sharp pointed objects depends on the nature and shape of the weapon, the amount of energy in the weapon or implement when it strikes the body, whether it is inflicted upon a moving or a still body, and the nature of the tissue injured. In the assessment of hemodynamically stable patients with sharp penetrating wounds, the main imaging procedure is Multidetector Computed Tomography (MDCT), especially used in complicated cases of penetrating injuries with an important impact on the final therapeutic choice. The diagnostic approach has been changed by MDCT due to its technical improvements, in particular, faster data acquiring and upgraded image reconstructions.

Utility of three-dimensional computed tomography for the surgical management of rib fractures

BACKGROUND

Surgical stabilization of flail chest is increasingly recognized as a valid approach to improve pulmonary mechanics in selected trauma patients. The use of two-dimensional (2D) computed tomography (CT) has become almost universal in the assessment of blunt chest trauma and multiple rib fractures. We hypothesized that three-dimensional (3D) CT adds valuable information to the preoperative plan for fixation of rib fractures.

METHODS

Using a retrospective cohort of 35 consecutive adult patients with flail chest requiring surgery, we evaluated the intraobserver and interobserver reliability of plain radiographs, 2D CT and 3D CT, for the identification of rib fractures and identified how often the surgical plan changed with the addition of the information provided by the 3D CT. Two fellowship-trained orthopedic trauma surgeons who regularly operate on rib fractures in their clinical practice and were not involved in the treatment of the study population evaluated the radiographic data.

RESULTS

Intraobserver and interobserver reliability was excellent for both 2D CT and 3D CT and was the highest for 2D CT. Overall, 2D CT had the highest diagnostic accuracy for detecting rib fractures as compared with plain radiographs and 3D CT. However, 3D CT changed the surgical tactic in 65.7% of the cases.

CONCLUSION

We conclude that 3D CT is not as accurate as 2D CT for rib fracture diagnostic purposes; it seems to be an important tool for the preoperative planning of rib fracture fixation.

LEVEL OF EVIDENCE

Diagnostic study, level II.

The significance of routine thoracic computed tomography in patients with blunt chest trauma

PURPOSE

The purpose of this study is to investigate whether the use of thoracic computed tomography (TCT) as part of nonselective computed tomography (CT) guidelines is superior to selective CT during the diagnosis of blunt chest trauma.

SUBJECTS AND METHODS

This study was planned as a prospective cohort study, and it was conducted at the emergency department between 2013 and 2014. A total of 260 adult patients who did not meet the exclusion criteria were enrolled in the study. All patients were evaluated by an emergency physician, and their primary surveys were completed based on the Advanced Trauma Life Support (ATLS) principles. Based on the initial findings and ATLS recommendations, patients in whom thoracic CT was indicated were determined (selective CT group). Routine CTs were then performed on all patients.

RESULTS

Thoracic injuries were found in 97 (37.3%) patients following routine TCT. In 53 (20%) patients, thoracic injuries were found by selective CT. Routine TCT was able to detect chest injury in 44 (16%) patients for whom selective TCT would not otherwise be ordered based on the EP evaluation (nonselective TCT group). Five (2%) patients in this nonselective TCT group required tube thoracostomy, while there was no additional treatment provided for thoracic injuries in the remaining 39 (15%).

CONCLUSION

In conclusion, we found that the nonselective TCT method was superior to the selective TCT method in detecting thoracic injuries in patients with blunt trauma. Furthermore, we were able to demonstrate that the nonselective TCT method can change the course of patient management albeit at low rates.

Prevalence of large and occult pneumothoraces in patients with severe blunt trauma upon hospital admission: experience of 526 cases in a French level 1 trauma center

BACKGROUND

Occult pneumothoraces (PTXs), which are not visible on chest x-ray, may progress to tension PTX. The aim of study was to establish the prevalence of large occult PTXs upon admission of patients with severe blunt trauma, according to prehospital mechanical ventilation.

METHODS

Patients with severe trauma consecutively admitted to our institution for 5 years were retrospectively analyzed. All patients with blunt thoracic trauma who had undergone computed tomographic (CT) within the first hour of hospitalization were included. Mechanical ventilation was considered as early if it was introduced in the prehospital period or on arrival at the hospital. Occult PTXs were defined as PTXs not visible on chest x-ray. All PTXs were measured on CT scan (largest thickness and vertical dimension). Large occult PTXs were defined by a largest thickness of 30 mm or more.

RESULTS

Of the 526 patients studied, 395 (75%) were male, mean age was 37.9 years, mean Injury Severity Score was 22.2, and 247 (47%) received early mechanical ventilation. Of 429 diagnosed PTXs, 296 (69%) were occult. The proportion of occult PTXs classified as large was 11% (95% confidence interval, 8%-15%). The overall prevalence of large occult PTXs was 6% (95% confidence interval, 4%-8%). Both CT measurements and proportion of large occult PTXs were found statistically comparable in patients with or without mechanical ventilation.

CONCLUSIONS

Six percent of studied patients with severe trauma had a large and occult PTX as soon as admission despite a normal chest x-ray result. The observed sizes and rates of occult PTX were comparable regardless of the initiation of early mechanical ventilation.

Damage control radiology in the severely injured patient: what the anaesthetist needs to know

In the treatment of severely injured patients, the term 'damage control radiology' has been used to parallel the modern concept of damage control surgery and the allied development of continuous damage control resuscitation from patient retrieval, through all transfers, to appropriate primary treatment. The aims of damage control radiology are (i) rapid identification of life-threatening injuries including bleeding sites, (ii) identification or exclusion of head or spinal injury, and (iii) prompt and accurate triage of patients to the operating theatre for thoracic, abdominal, or both surgeries or the angiography suite for endovascular haemorrhage control. If we are to achieve these aims, patients must have immediate access to modern multidetector computed tomography (MDCT) which is without doubt the most potent weapon in the diagnostic armamentarium. The most severely injured patients are those who have the most to benefit from early diagnosis and life-saving therapies. The traditional teaching that these patients should go immediately to surgery is challenged by technological developments in MDCT and recent clinical evidence.

Multidetector computer tomography: evaluation of blunt chest trauma in adults

Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall.

Predictors of poor outcomes after significant chest trauma in multiply injured patients: a retrospective analysis from the German Trauma Registry (Trauma Register DGU®)

Background

Blunt thoracic trauma is one of the critical injury mechanisms in multiply injured trauma victims. Although these patients present a plethora of potential structural damages to vital organs, it remains debated which injuries actually influence outcome and thereby should be addressed initially. Hence, the aim of this study was to identify the influence of critical structural damages on mortality.

Methods

All patients in the database of the TraumaRegister DGU® (TR-DGU) from 2002–2011 with AIS Chest ≥ 2, blunt trauma, age of 16 or older and an ISS ≥ 16 were analyzed.

Outcome parameters were in-hospital mortality as well as ventilation time in patients surviving the initial 14 days after trauma.

Results

22613 Patients were included (mean ISS 30.5 ± 12.6; 74.7% male; Mean Age 46.1 ± 197 years; mortality 17.5%; mean duration of ventilation 7.3 ± 11.5; mean ICU stay 11.7 ± 14.1 days).

Only a limited number of specific injuries had a significant impact on survival. Major thoracic vessel injuries (AIS ≥5), bilateral lung contusion, bilateral flail chest, structural heart injury (AIS ≥3) significantly influence mortality in study patients. Several extrathoracic factors (age, blood transfusion, systolic blood pressure and extrathoracic severe injuries) were also predictive of increased mortality.

Most injuries of the thoracic wall had no or only a moderate effect on the duration of ventilation. Injuries to the lung (laceration, contusion or pneumothoraces) had a moderate prolonging effect. Cardiac injuries and severe injuries to the thoracic vessels induced a substantially prolonged ventilation interval.

Conclusions

We demonstrate quantitatively the influence of specific structural damages of the chest on critical outcome parameters. While most injuries of the chest wall have no or only limited impact in the study collective, injuries to the lung overall show adverse outcome. Injuries to the heart or thoracic vessels have a devastating prognosis following blunt chest trauma.

Hemothorax after the intravenous administration of tissue plasminogen activator in a patient with acute ischemic stroke and rib fractures

A 79-year-old man experienced sudden-onset left hemiparesis and disturbance of consciousness. Diffusion-weighted magnetic resonance imaging showed an acute ischemic stroke in the territory of the right middle cerebral artery. He underwent systemic thrombolysis via the intravenous administration of tissue plasminogen activator (t-PA). Chest radiography and computed tomography performed the following day showed severe hemothorax with atelectasis of the left lung and multiple rib fractures; the initial chest radiogram had revealed rib fractures but we did not recognize them at the time. Conservative treatment with the placement of chest tubes was successful, and the patient recovered without further deterioration. Although systemic thrombolysis with t-PA is an accepted treatment for acute cerebral ischemic stroke, posttreatment intracranial hemorrhage has a negative effect on prognosis. Extracranial bleeding is a rare complication, and our search of the literature found no reports of hemothorax after treatment with t-PA in patients with cerebral ischemic stroke. We have reported a rare case of severe hemothorax after systemic thrombolysis with t-PA. This important complication indicates the need to rule out thoracic trauma with radiography and computed tomography of the chest.

Pneumomediastinum in blunt chest trauma: a case report and review of the literature

Blunt trauma is the most common mechanism of injury in patients with pneumomediastinum and may occur in up to 10% of patients with severe blunt thoracic and cervical trauma. In this case report we present a 24-year-old man with pneumomediastinum due to blunt chest trauma after jumping from a bridge into a river. He complained of persistent retrosternal pain with exacerbation during deep inspiration. Physical examination showed only a slight tenderness of the sternum and the extended Focused Assessment with Sonography for Trauma (e-FAST) was normal. Pneumomediastinum was suspected by chest X-ray and confirmed by computed tomography, which showed a lung contusion as probable cause of the pneumomediastinum due to the "Mackling effect." Sonographic findings consistent with pneumomediastinum, like the "air gap" sign, are helpful for quick bedside diagnosis, but the diagnostic criteria are not yet as well established as for pneumothorax. This present case shows that despite minimal findings in physical examination and a normal e-FAST a pneumomediastinum is still possible in a patient with chest pain after blunt chest trauma. Therefore, pneumomediastinum should always be considered to prevent missing major aerodigestive injuries, which can be associated with a high mortality rate.

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.

Does trauma team activation associate with the time to CT scan for those suspected of serious head injuries?

Background

Traumatic brain injury (TBI) constitutes the leading cause of posttraumatic mortality. Practically, the major interventions required to treat TBI predicate expedited transfer to CT after excluding other immediately life-threatening conditions. At our center, trauma responses variably consist of either full trauma activation (FTA) including an attending trauma surgeon or a non-trauma team response (NTTR). We sought to explore whether FTAs expedited the time to CT head (TTCTH).

Methods

Retrospective review of augmented demographics of 88 serious head injuries identified from a Regional Trauma Registry within one year at a level I trauma center. The inclusion criteria consisted of a diagnosis of head injury recorded as intubated or GCS < 13; and CT-head scanning after arriving the emergency department. Data was analyzed using STATA.

Results

There were 58 FTAs and 30 NTTRs; 86% of FTAs and 17% of NTTRs were intubated prehospital out of 101 charts reviewed in detail; 13 were excluded due to missing data. Although FTAs were more seriously injured (median ISS 29, MAIS head 19, GCS score at scene 6.0), NTTRs were also severely injured (median ISS 25, MAIS head 21, GCS at scene 10) and older (median 54 vs. 26 years). Median TTCTH was double without dedicated FTA (median 50 vs. 26 minutes, p < 0.001), despite similar justifiable delays (53% NTTR, 52% FTA). Without FTA, most delays (69%) were for emergency intubation. TTCTH after securing the airway was longer for NTTR group (median 38 vs. 26 minutes, p =0.0013). Even with no requirements for ED interventions, TTCTH for FTA was less than half versus NTTR (25 vs. 61 minutes, p =0.0013). Multivariate regression analysis indicated age and FTA with an attending surgeon as significant predictors of TTCTH, although the majority of variability in TTCTH was not explained by these two variables (R² = 0.33).

Conclusion

Full trauma activations involving attending trauma surgeons were quicker at transferring serious head injury patients to CT. Patients with FTA were younger and more seriously injured. Discerning the reasons for delays to CT should be used to refine protocols aimed at minimizing unnecessary delays and enhancing workforce efficiency and clinical outcome.

Report of a rare case: occult hemothorax due to blunt trauma without obvious injury to other organs

Traumatic hemothorax commonly occurs accompanied by organ damage, such as rib fractures, lung injury and diaphragm rupture. Our reported patient was a 61-year-old man who fell down from a stepladder about 1 meter in height, resulting in a heavy blow to the left abdomen. He consulted a clinic because of left chest pain the next day and was transported to the emergency center of our hospital on diagnosis of hemothorax with hemorrhagic shock.On computed tomography scanning with contrast medium, left hemothorax without rib fracture, diaphragm rupture or obvious organ injury was evident. We found only bleeding to the thoracic space from a branch of the left inferior phrenic artery without involvement of the abdomen. The patient underwent percutaneous angiography and embolization for hemostasis, and subsequently thoracotomy in order to check the active bleeding and remove the hematoma to improve respiratory. As thoracotomy findings, we found damage of a branch of the left inferior phrenic artery to the thoracic space without diaphragm rupture, and sutured the lesion. Such active intervention followed by surgical procedures was effective and should be considered for rare occurrences like the present case. We must consider not only traumatic diaphragm rupture, but also vascular damage by pressure trauma as etiological factors for hemothorax.

Impact on survival of whole-body computed tomography before emergency bleeding control in patients with severe blunt trauma

Introduction

Whole-body computed tomography (CT) has gained importance in the early diagnostic phase of trauma care. However, the diagnostic value of CT for seriously injured patients is not thoroughly clarified. This study assessed whether preoperative CT beneficially affected survival of patients with blunt trauma who required emergency bleeding control.

Methods

This retrospective study was conducted from January 2004 to December 2010 in two tertiary trauma centers in Japan. The primary inclusion criterion was patients with blunt trauma who required emergency bleeding control (surgery or transcatheter arterial embolization). CT before emergency bleeding control was performed at the attending physician's discretion based on individual patient condition (for example, hemodynamic stability or certain abnormalities in the primary survey). We assessed covariates associated with 28-day mortality with multivariate logistic regression analysis and evaluated standardized mortality ratio (SMR, ratio of observed to predicted mortality by Trauma and Injury Severity Score (TRISS) method) in two subgroups of patients who did or did not undergo CT.

Results

The inclusion criterion was fulfilled by 152 patients with a median Injury Severity Score of 35.3. During the early resuscitation phase, 132 (87%) patients underwent CT and 20 (13%) did not. Severity of injury was significantly higher in the non-CT versus CT group patients. Observed mortality rate was significantly lower in the CT versus non-CT group (18% vs. 80%, P <0.001). Multivariate adjustment for the probability of survival (Ps) by TRISS method confirmed CT as an independent predictor for 28-day mortality (adjusted OR, 7.22; 95% CI, 1.76 to 29.60; P = 0.006). In the subgroup with less severe trauma (TRISS Ps ≥50%), SMR in the CT group was 0.63 (95% CI, 0.23 to 1.03; P = 0.066), indicating no significant difference between observed and predicted mortality in the CT group. In contrast, in the subgroup with more severe trauma (TRISS Ps <50%), SMR was 0.65 (95% CI, 0.41 to 0.90; P = 0.004) only in the CT group, whereas the difference between observed and predicted mortality was not significant in the non-CT group, suggesting a possible beneficial effect of CT on survival only in trauma patients at high risk of death.

Conclusion

CT performed before emergency bleeding control might be associated with improved survival, especially in severe trauma patients with TRISS Ps of <50%.

Using thoracic ultrasonography to accurately assess pneumothorax progression during positive pressure ventilation: a comparison with CT scanning

BACKGROUND

Although thoracic ultrasonography accurately determines the size and extent of occult pneumothoraces (PTXs) in spontaneously breathing patients, there is uncertainty about patients receiving positive pressure ventilation. We compared the lung point (ie, the area where the collapsed lung still adheres to the inside of the chest wall) using the two modalities ultrasonography and CT scanning to determine whether ultrasonography can be used reliably to assess PTX progression in a positive-pressure-ventilated porcine model.

METHODS

Air was introduced in incremental steps into fi ve hemithoraces in three intubated porcine models. The lung point was identified on ultrasound imaging and referenced against the lateral limit of the intrapleural air space identified on the CT scans. The distance from the sternum to the lung point (S-LP) was measured on the CT scans and correlated to the insufflated air volume.

RESULTS

The mean total difference between the 131 ultrasound and CT scan lung points was 6.8 mm (SD, 7.1 mm; range, 0.0-29.3 mm). A mixed-model regression analysis showed a linear relationship between the S-LP distances and the PTX volume ( P , .001).

CONCLUSIONS

In an experimental porcine model, we found a linear relation between the PTX size and the lateral position of the lung point. The accuracy of thoracic ultrasonography for identifying the lung point (and, thus, the PTX extent) was comparable to that of CT imaging. These clinically relevant results suggest that ultrasonography may be safe and accurate in monitoring PTX progression during positive pressure ventilation.

Retrospective review of the use and costs of routine chest x rays in a trauma setting

INTRODUCTION

Chest x-rays (CXR) are routinely obtained on blunt trauma patients. Many patients also receive additional imaging with thoracic computed tomography scans for other indications. We hypothesized that in hemodynamically normal, awake and alert blunt trauma patients, CXR can be deferred in those who will also receive a TCT with significant cost savings.

METHODS

We retrospectively reviewed the charts of trauma patients from 1/1/2010 to 12/31/2010 who received both a CXR and TCT in the trauma room. Billing and cost data were collected from various hospital sources.

RESULTS

239 patients who met inclusion and exclusion criteria and received CXR and TCT between 1/1/2010 and 12/31/2010. The sensitivity of CXR was 19% (95% CI: 10.8% to 31%) and the specificity was 91.7% (95% CI: 86.7% to 95%). The false positive rate for CXR was 35.8% (95% CI: 21.7% to 52.8%) and the false negative rate was 24.5% (95% CI: 18.8% to 31.2%). The precision of CXR was 42.3% (95% CI: 25.5% to 61.1%) and the overall accuracy was 74.1% (95% CI: 68.1% to 79.2%). If routine chest xray were eliminated in these patients, the estimated cost savings ranged from $14,641 to $142,185, using three different methods of cost analysis.

CONCLUSIONS

In patients who are hemodynamically normal and who will be receiving a TCT, deferring a CXR would result in an estimated cost savings up to $142,185. Additionally, TCT is more sensitive and specific than CXR in identifying injuries in patients who have sustained blunt trauma to the thorax.

The intrapleural volume threshold for ultrasound detection of pneumothoraces: an experimental study on porcine models

Background

Small pneumothoraxes (PTXs) may not impart an immediate threat to trauma patients after chest injuries. However, the amount of pleural air may increase and become a concern for patients who require positive pressure ventilation or air ambulance transport. Lung ultrasonography (US) is a reliable tool in finding intrapleural air, but the performance characteristics regarding the detection of small PTXs need to be defined. The study aimed to define the volume threshold of intrapleural air when PTXs are accurately diagnosed with US and compare this volume with that for chest x-ray (CXR).

Methods

Air was insufflated into a unilateral pleural catheter in seven incremental steps (10, 25, 50, 100, 200, 350 and 500 mL) in 20 intubated porcine models, followed by a diagnostic evaluation with US and a supine anteroposterior CXR. The sonographers continued the US scanning until the PTXs could be ruled in, based on the pathognomonic US “lung point” sign. The corresponding threshold volume was noted. A senior radiologist interpreted the CXR images.

Results

The mean threshold volume to confirm the diagnosis of PTX using US was 18 mL (standard deviation of 13 mL). Sixty-five percent of the PTXs were already diagnosed at 10 mL of intrapleural air; 25%, at 25 mL; and the last 10%, at 50 mL. At an air volume of 50 mL, the radiologist only identified four out of 20 PTXs in the CXR pictures; i.e., a sensitivity of 20% (95% CI: 7%, 44%). The sensitivity of CXR increased as a function of volume but leveled off at 67%, leaving one-third (1/3) of the PTXs unidentified after 500 mL of insufflated air.

Conclusion

Lung US is very accurate in diagnosing even small amounts of intrapleural air and should be performed by clinicians treating chest trauma patients when PTX is among the differential diagnoses.

Management of thoracic trauma in emergency service: Analysis of 1139 cases

OBJECTIVE

Thoracic trauma is a common cause of significant morbidity and mortality. This study presents a series of thoracic trauma with the aim to assess epidemiologic features, distribution of pathologies, additional systemic injuries, diagnosis, management and outcome.

METHODOLOGY

Between January 2007 and December 2011, all patients with thorax trauma admitted to the emergency service of our hospital were retrospectively reviewed with respect to age, gender, etiological factors, distribution of pathologies, additional systemic injuries, diagnosis, treatment modalities, referral and outcome.

RESULTS

A total of 1139 patients with thorax trauma were included in the study. Of these, 698 (61.3%) were male and 441 (38.7%) were female, and the average age was 54.17±17.39 years. 1090 (95.7%) of the patients had blunt trauma, whereas 49 (4.3%) had penetrating trauma. Etiological factors were falls in 792 (69.5%), motor vehicle accidents in 259 (22.8%), animal related accidents in 39 (3.4%) and penetrating injuries in 49 (4.2%) patients. It was found that 229 (20%) patients had single, 101 (8.9%) had double, 5 (3%) had three or more, 10 (0.9%) had bilateral rib fractures and 19 (1.7%) had sternal fracture. Pneumothorax was diagnosed in 58 (5.1%) patients, whereas hemothorax, hemopneuomothorax and other system injuries were diagnosed in 36 (3.2%), 38(3.3%) and 292 (25.6%) respectively. In our series, thirteen patients (mortality rate 1.1%) died as result of hemorrhagic shock (n=8), respiratory distress (n=3) and severe multiple trauma (n=2).

CONCLUSION

Although majority of the patients with thorax trauma receive treatment as outpatients; thoracic traumas may be a life threatening condition, and should be identified and treated immediately. Mortality varies based on etiological factors, additional systemic pathologies, capabilities of the hospital especially diagnostic and treatment facilities in emergency services. We believe that a multidisciplinary approach to the patients with severe thorax trauma, and the opportunities of emergency bedside thoracotomy in emergency services will significantly reduce the morbidity and mortality.

Risk factors of pneumothorax after endobronchial ultrasound-guided transbronchial biopsy for peripheral lung lesions

Background

The risk of endobronchial ultrasound-guided transbronchial biopsy-related pneumothorax is a major concern and warrants further studies. The aim of our study was to estimate the risk of pneumothorax after this procedure and identify its risk factors.

Methods

From 2007 to 2011, 399 patients who underwent endobronchial ultrasound-guided transbronchial biopsy for peripheral lung lesions were included in this study. The variables analyzed included patient factors, lesion factors and procedure factors. Multivariate logistic regression analysis was used to identify independent risk factors for pneumothorax.

Results

The incidence of pneumothorax was 3.3% (13/399). Chest tube placement was required for 31% (4/13) of pneumothoraces. Independent risk factors for pneumothorax included pulmonary emphysema (OR, 55.09; 95% CI, 9.37–324.03; p<0.001) and probe position adjacent to the lesion (OR, 17.01; 95% CI, 2.85–101.64; p = 0.002). The number of biopsy specimens, age, sex, history of prior lung surgery and lesion size, location and character did not influence the risk of pneumothorax in our analyses.

Conclusions

The risk of pneumothorax after endobronchial ultrasound-guided transbronchial biopsy is low. To further reduce the risk of pneumothorax, every effort should be made to advance the endobronchial ultrasound probe into the bronchus where it is imaged within the target lesion before embarking on transbronchial biopsy.

[Hypothermia at admission increases the risk of pulmonary contusion's infection in intubated trauma patients]

OBJECTIVES

Pulmonary contusion (PC) is common in cases of polytrauma. The aim of this study was to perform a multivariate analysis of risk factors associated with the occurrence of infection in PC and analyze the microbiological epidemiology.

PATIENTS AND METHODS

All patients with PC admitted to the intensive care unit (ICU) between January 2002 and December 2006 were included in this retrospective observational study. Patients with penetrating thoracic trauma or those who died in the 48hours following admission to hospital were excluded. Diagnosis of bacterial infection in PC was performed if hyperthermia was associated with a positive quantitative culture (103 colony forming units/mL) on the bronchial sample. Univariate analysis provided statistical difference between variables that were integrated in the multivariate analysis model. Multivariate analysis was then performed to determine the risk factors of bacterial infection in PC.

RESULTS

One hundred and seventeen patients were included. The incidence of bacterial infection in PC was 33.3% (39 patients). The most frequently encountered bacteria were Haemophilus sp., Staphylococcus aureus, Enterobacteriaceae, Pseudomonas sp. and Streptococcus sp. According to multivariate analysis, the existence of hypothermia at hospital admission increased the risk of PC infection (OR=2.61; IC 95% [4.2-13.3]).

CONCLUSION

In conclusion, PC was infected in 33.3% of cases. The existence of hypothermia was identified as a risk factor. A prospective study is warranted to confirm these results.

Automated quantification of pneumothorax in CT

An automated, computer-aided diagnosis (CAD) algorithm for the quantification of pneumothoraces from Multidetector Computed Tomography (MDCT) images has been developed. Algorithm performance was evaluated through comparison to manual segmentation by expert radiologists. A combination of two-dimensional and three-dimensional processing techniques was incorporated to reduce required processing time by two-thirds (as compared to similar techniques). Volumetric measurements on relative pneumothorax size were obtained and the overall performance of the automated method shows an average error of just below 1%.

Radiographic assessment of splenic injury without contrast: is contrast truly needed?

INTRODUCTION

Computed tomography (CT) has become an essential tool in the assessment of the stable trauma patient. Intravenous (i.v.) contrast is commonly relied upon to provide superior image quality, particularly for solid-organ injury. However, a substantial proportion of injured patients have contraindications to i.v. contrast. Little information exists concerning the repercussions of CT imaging without i.v. contrast, specifically for splenic injury.

METHODS

We performed a retrospective analysis using data from our trauma registry and chart review as part of a quality improvement project at our institution. All patients with splenic injury, during a 3-year period (2008-2010), where a CT of the abdomen without i.v. contrast (DRY) early during their admission were selected. All splenic injuries had to have been verified with abdominal CT imaging with i.v. contrast (CONTRAST) or via intraoperative findings. DRY images were independently read by a single, blinded, radiologist and assessed for parenchymal injury or "suspicious" splenic injury findings and compared with CONTRAST imaging results or intraoperative findings.

RESULTS

During the time period of the study, 319 patients had documented splenic injury with 44 (14%) patients undergoing DRY imaging, which was also verified by CONTRAST imaging or operative findings. Splenic parenchymal injury was only visualized in 38% of patients DRY patients. "Suspicious" splenic injury radiographic findings were common. When these less-specific findings for splenic injury were incorporated in the radiographic assessment, DRY imaging had more than 93% sensitivity for detecting splenic injury.

CONCLUSION

DRY imaging is increasingly being performed after injury and has a low sensitivity in detecting splenic parenchymal injury. However, less-specific radiographic findings suspicious for splenic injury in combination provide high sensitivity for the detection of splenic injury. These results suggest CONTRAST imaging is preferred to detect splenic injury; however, in those patients who have contraindications to i.v. contrast, DRY imagining may be able to select those who require close monitoring or intervention.

Multidetector computed tomography of chest trauma: indications, technique and interpretation

Background

Chest traumas are a significant cause of mortality and morbidity, especially in the younger population.MethodsDiagnostic imaging plays a key role in their management. Multidetector computed tomography (MDCT) is the most important imaging method in this field. Its advantages include especially high speed and high geometric resolution in any plane.ResultsThe method allows us to view large parts of the body with minimal motion artifacts and to create accurate multiplanar and three-dimensional (3D) reformations, which make the diagnosis significantly more accurate. Because of its advantages MDCT has become the first-choice method in high-energy traumas.ConclusionThis article summarises the position of MDCT in the diagnostic algorithm of chest injuries, technical aspects of the examination and imaging findings in traumas of the individual chest compartments.

Teaching Points

• Diagnostic imaging plays a key role in the management of high-energy chest trauma.

• MDCT is the most important imaging method in this kind of injury, as detailed information can be acquired in a short acquisition time.

• Multiplanar and three-dimensional (3D) reformattings make the diagnosis significantly more accurate.

Revisiting signs, strengths and weaknesses of Standard Chest Radiography in patients of Acute Dyspnea in the Emergency Department

Dyspnoea, defined as an uncomfortable awareness of breathing, together with thoracic pain are two of the most frequent symptoms of presentation of thoracic diseases in the Emergency Department (ED). Causes of dyspnoea are various and involve not only cardiovascular and respiratory systems. In the emergency setting, thoracic imaging by standard chest X-ray (CXR) plays a crucial role in the diagnostic process, because it is of fast execution and relatively not expensive. Although radiologists are responsible for the final reading of chest radiographs, very often the clinicians, and in particular the emergency physicians, are alone in the emergency room facing this task. In literature many studies have demonstrated how important and essential is an accurate direct interpretation by the clinician without the need of an immediate reading by the radiologist. Moreover, the sensitivity of CXR is much impaired when the study is performed at bedside by portable machines, particularly in the diagnosis of some important causes of acute dyspnoea, such as pulmonary embolism, pneumothorax, and pulmonary edema. In these cases, a high inter-observer variability of bedside CXR reading limits the diagnostic usefulness of the methodology and complicates the differential diagnosis. The aim of this review is to analyze the radiologic signs and the correct use of CXR in the most important conditions that cause cardiac and pulmonary dyspnoea, as acute exacerbation of chronic obstructive pulmonary disease, acute pulmonary oedema, acute pulmonary trombo-embolism, pneumothorax and pleural effusion, and to focus indications and limitations of this diagnostic tool.

The role of early multislice computed tomography in major trauma

Whole-body multislice spiral computed tomography (MSCT) has become a very important dignostic tool in the management of patients with multiple injuries. Many reports exist which demonstrate the feasibility and the benefit when using whole-body MSCT in the early phase of in-hospital management of trauma patients. Even in hemodynamically instable patients (except cardiac arrest), whole-body MSCT can be used and is a safe diagnostic procedure. While the diagnostic superiority of multislice computed tomography is proven for different organ regions (e.g. head/brain, chest, abdomen, pelvis and spine), its use as a single whole-body scan is still part of an ongoing discussion. Especially concerns about radiation exposure are the reason for uncertainty about when using whole-body trauma scan. Predefined scan protocols and individual positioning of patients may help to keep radiation dose as minimal as possible. To justify higher radiation dose, the indication must be chosen appropriately. Therefore, the use of a sensitive and specific triage scheme seems to be reasonable. Overscanning patients with minor trauma needs to be avoided, while the benefit for patients with severe multiple injuries is obvious.

Can cervical spine computed tomography assist in detecting occult pneumothoraces?

INTRODUCTION

Screening CT often detects posttraumatic pneumothoraces that were not diagnosed on a preceding supine anteroposterior chest radiograph (occult pneumothoraces (OPTXs)). Because abdominal CT imaging misses OPTXs in the upper thorax, the objective of this study was to evaluate the utility of cervical spine (C-spine) CT screening for diagnosing OPTXs.

METHODS

A dual-institution (Foothills Medical Centre and Grady Memorial Hospital) retrospective review of consecutive OPTXs was performed. The accuracy of various CT screening protocols in detecting OPTXs was compared.

RESULTS

OPTXs were detected in 75 patients. Patient demographics and injury characteristics were similar between centres (65% male; 97% blunt mechanism; 29% hemodynamically unstable; mean ISS=27; mean length of stay=22 days; mortality=9%)(p>0.05). Patients received either abdominal (41%) or thoraco-abdominal (59%) CT imaging. Most patients (89%) also underwent C-spine CT imaging. OPTXs were evident on thoracic CT in 100% (44/44), abdominal CT in 83% (62/75), and C-spine CT in 82% (55/67) of cases. All patients with OPTXs identified solely on thoracic CT (i.e. not abdominal) who also underwent imaging of their C-spine could have had their OTPXs diagnosed by using the pulmonary windows setting of their C-spine CT series. Combining C-spine and abdominal CT screening diagnosed all OPTXs (67/67) detected on thoracic CT, for patients who also underwent these investigations.

CONCLUSIONS

OPTXs were evident on thoracic (and not abdominal) CT in 17% of severely injured patients. For patients who also underwent C-spine imaging, all OPTXs isolated to thoracic CT could be diagnosed by using the pulmonary windows setting of their C-spine CT imaging protocol. All OPTXs, regardless of intra-thoracic location, could also be detected by combining C-spine and abdominal CT screening.

Indications and performance of pelvic radiography in patients with blunt trauma

OBJECTIVES

The objectives of this study are to validate a set of clinical variables to identify patients with pelvic fractures and to determine the sensitivity of anteroposterior (AP) pelvic radiographs in patients with pelvic fractures.

METHODS

We conducted a prospective observational cohort study of adults (>18 years) with blunt torso trauma evaluated with abdominal/pelvic computed tomography. Physicians providing care in the emergency department documented history and physical examination findings after initial evaluation. High-risk variables included any of the following: hypotension (systolic blood pressure <90 mm Hg), Glasgow Coma Scale score less than 14, pelvic bone tenderness, or instability. Pelvic fractures were present if the orthopedic faculty documented a fracture to the pubis, ilium, ischium, or sacrum.

RESULTS

We enrolled 4737 patients, including 289 (6.1%; 95% confidence interval [CI], 5.4%-6.8%) with pelvic fractures. Of the 289 patients, 256 (88.6%; 95% CI, 84.3%-92.0%) had at least one of the high-risk variables identified. Initial plain AP radiographs identified 234 (81.0%; 95% CI, 76.0%-85.3%) of 289 patients with pelvic fractures. The high-risk variables identified all 87 patients (100%; 95% CI, 96.6%-100%) undergoing surgery, whereas plain AP pelvic radiography identified a fracture in 83 patients (95.4%; 95% CI, 88.6%-98.7%) undergoing surgery.

CONCLUSION

Previously identified high-risk variables for pelvic fracture identify most but not all patients with pelvic fractures. However, these high-risk variables identify all patients undergoing surgery and may be implemented as screening criteria for pelvic radiography. Anteroposterior pelvic radiographs fail to demonstrate a fracture in a substantial number of patients with pelvic fracture including patients who undergo surgery.

Anteroposterior chest radiograph vs. chest CT scan in early detection of pneumothorax in trauma patients

Pneumothorax is a common complication following blunt chest wall trauma. In these patients, because of the restrictions regarding immobilization of the cervical spine, Anteroposterior (AP) chest radiograph is usually the most feasible initial study which is not as sensitive as the erect chest X-ray or CT chest for detection of a pneumothorax. We will present 3 case reports which serve for better understanding of the entity of occult pneumothorax. The first case is an example of a true occult pneumothorax where an initial AP chest X-ray revealed no evidence of pneumothorax and a CT chest immediately performed revealed evidence of pneumothorax. The second case represents an example of a missed rather than a truly occult pneumothorax where the initial chest radiograph revealed clues suggesting the presence of pneumothorax which were missed by the reading radiologist. The third case emphasizes the fact that "occult pneumothorax is predictable". The presence of subcutaneous emphesema and pulmonary contusion should call for further imaging with CT chest to rule out pneumothorax. Thoracic CT scan is therefore the "gold standard" for early detection of a pneumothorax in trauma patients. This report aims to sensitize readers to the entity of occult pneumothorax and create awareness among intensivists and ER physicians regarding the proper diagnosis and management.

Clinical management of occult hemothorax: a prospective study of 81 patients

BACKGROUND

Intrapleural blood detected by computed tomography scan, but not evident on plain chest radiograph, defines occult hemothorax. This study determined the role for tube thoracostomy.

METHODS

Hemothorax was quantified on computed tomography by measuring the deepest lamellar fluid stripe at the most dependent portion. Data were collected prospectively on demographics, injury mechanism/severity, chest injuries, mechanical ventilation, hospital length of stay, complications, and outcome. Indications for tube thoracostomy were recorded.

RESULTS

Tube thoracostomy was avoided in 67 patients (83%). Indications for chest tube placement included progression of hemothorax (8), desaturation (4), and delayed hemothorax (2). Patients with intrapleural fluid thickness greater than 1.5 cm were 4 times more likely to require tube thoracostomy.

CONCLUSIONS

Occult hemothorax can be managed successfully without tube thoracostomy in most cases. Mechanical ventilation is not an indication for chest tube placement. Accompanying occult pneumothorax may be expected in 50% of cases, but did not affect clinical management.

Standard Computed Tomography of the Chest, Abdomen, and Pelvis Is Sensitive and Cost-Effective for the Detection of Fractures of the Shoulder Girdle

Computed tomography of the chest, abdomen, and pelvis (CTCAP) has become the mainstay of diagnosis in stable blunt trauma patients. The purpose of this study was to investigate whether standard CTCAP has adequate sensitivity to identify fractures of the scapula, clavicle, and humeral head to replace routine radiographs of the shoulder. A retrospective chart review was carried out from January 1, 2004, to December 31, 2007, at Morristown Memorial Hospital. Inclusion criteria were all shoulder fracture patients in our trauma registry who underwent both a CTCAP and plain radiographs of the injured shoulder. Data were collected for patient age, sex, Injury Severity Score, mechanism of injury, and fracture location. Sensitivity was calculated for each diagnostic modality as well as hospital costs and radiation dose of plain radiographs. A total of 374 charts were reviewed and 98 patients were included in the study with a total of 117 fractures. The sensitivity of trauma CTCAP for scapula fractures was 100 per cent, clavicle fractures 98 per cent, and humeral head fractures 100 per cent. The sensitivity of the shoulder series for scapula fractures was 60 per cent, clavicle fractures 85 per cent, and humeral head fractures 100 per cent. The plain radiographs added $298 in hospital charges and 0.191 mSv of radiation per patient. CTCAP is a sensitive tool for identifying fractures in the shoulder girdle. Therefore, CTCAP can replace the routine radiographs of the shoulder resulting in less total radiation exposure of the trauma patients. This also would lead to lower healthcare cost and better diagnostic workflow.

MDCT for computerized volumetry of pneumothoraces in pediatric patients

RATIONALE AND OBJECTIVES

Our purpose in this study was to develop an automated computer-aided volumetry (CAV) scheme for quantifying pneumothorax in multidetector computed tomography (MDCT) images for pediatric patients and to investigate the imaging parameters that may affect its accuracy.

MATERIALS AND METHODS

Fifty-eight consecutive pediatric patients (mean age 12 ± 6 years) with pneumothorax who underwent MDCT for evaluation were collected retrospectively for this study. All cases were imaged by a 16- or 64-MDCT scanner with weight-based kilovoltage, low-dose tube current, 1.0-1.5 pitch, 0.6-5.0 mm slice thickness, and a B70f (sharp) or B31f (soft) reconstruction kernel. Sixty-three pneumothoraces ≥1 mL were visually identified in the left (n = 30) and right (n = 33) lungs. Each identified pneumothorax was contoured manually on an Amira workstation V4.1.1 (Mercury Computer Systems, Chelmsford, MA) by two radiologists in consensus. The computerized volumes of the pneumothoraces were determined by application of our CAV scheme. The accuracy of our automated CAV scheme was evaluated by comparison between computerized volumetry and manual volumetry, for the total volume of pneumothoraces in the left and right lungs.

RESULTS

The mean difference between the computerized volumetry and the manual volumetry for all 63 pneumothoraces ≥1 mL was 8.2%. For pneumothoraces ≥10 mL, ≥50 mL, and ≥200 mL, the mean differences were 7.7% (n = 57), 7.3% (n = 33), and 6.4% (n = 13), respectively. The correlation coefficient was 0.99 between the computerized volume and the manual volume of pneumothoraces. Bland-Altman analysis showed that computerized volumetry has a mean difference of -5.1% compared to manual volumetry. For all pneumothoraces ≥10 mL, the mean differences for slice thickness ≤1.25 mm, = 1.5 mm, and = 5.0 mm were 6.1% (n = 28), 3.5% (n = 10), and 12.2% (n = 19), respectively. For the two reconstruction kernels, B70f and B31f, the mean differences were 6.3% (n = 42, B70f) and 11.7% (n = 15, B31f), respectively.

CONCLUSION

Our automated CAV scheme provides an accurate measurement of pneumothorax volume in MDCT images of pediatric patients. For accurate volumetric quantification of pneumothorax in children in MDCT images by use of the automated CAV scheme, we recommended reconstruction parameters based on a slice thickness ≤1.5 mm and the reconstruction kernel B70f.

Accuracy of conventional imaging of penetrating torso injuries in the trauma resuscitation room

OBJECTIVES

Chest X-ray (CXR), abdominal ultrasound, cardiac ultrasound, and abdominal X-ray are the most frequently used imaging modalities to radiologically evaluate patients with penetrating torso trauma. The aim of this study was to evaluate the accuracy of these imaging modalities.

METHODS

From January 2001 until January 2005, all consecutive patients with penetrating torso injuries presenting at the emergency department of a level 1 trauma center were included. Imaging modalities (chest/abdominal X-ray, abdominal/cardiac ultrasound), were compared retrospectively with a 'gold standard' (i.e. computed tomography or surgery within 2 h after arrival) or outcome of conservative treatment. The accuracy of the imaging modalities was calculated.

RESULTS

Three hundred and eighteen patients were included. On the basis of 299 CXRs, the sensitivity for diagnosing pneumothorax, hemothorax, and subcutaneous emphysema was 71, 63, and 61%, respectively. The sensitivity of abdominal ultrasound (N = 229) to detect free abdominal fluid and/or intra-abdominal injury was 65%. The specificity, positive predictive value, negative predictive value, and accuracy of the two imaging modalities to detect any of the diagnoses mentioned were >or=87%. Cardiac ultrasound (N = 31) did not show any false positive or negative results for detecting cardiac effusion. Pneumoperitoneum was not seen on abdominal X-ray in eight of 11 patients with perforation of a hollow organ.

CONCLUSION

Despite high specificity, positive predictive value, and negative predictive value, a considerable number of lesions remain undetected after CXR and abdominal ultrasound because of moderate-to-inadequate sensitivity. Abdominal X-ray hardly provides additional information. Careful clinical monitoring of patients is mandatory, particularly when computed tomography scan or operative treatment is not indicated.

Pictorial review: computed tomography features of cardiovascular emergencies and associated imminent decompensation

Multi-detector computed tomography (MDCT) scanner is available in most hospitals and is increasingly being used as the first line imaging in trauma and suspected cardiovascular emergencies, such as acute coronary syndrome, pulmonary artery thrombo-embolism, abdominal aortic aneurysm and acute haemorrhage (Ryan et al. Clin Radiol 60:599-607, 2005). A significant number of these patients are haemodynamically unstable and can rapidly progress into shock and death. Recognition of computed tomography (CT) signs of imminent cardiovascular decompensation will alert the clinical radiologist to the presence of shock. In this review, the imaging findings of cardiovascular emergencies in both acute traumatic and non-traumatic settings with associated signs of imminent decompensation will be described and illustrated.

The Clinical Significance of Occult Thoracic Injury in Blunt Trauma Patients

Increased use of thoracic CT (TCT) in diagnosis of blunt traumatic injury has identified many injuries previously undetected on screening chest x-ray (CXR), termed “occult injury.” The optimal management of occult rib fractures, pneumothoraces (PTX), hemothoraces (HTX), and pulmonary contusions is uncertain. Our objective was to determine the current management and clinical outcome of these occult blunt thoracic injuries. A retrospective review identified patients with blunt thoracic trauma who underwent both CXR and TCT over a 2-year period at a Level I urban trauma center. Patients with acute rib fractures, PTX, HTX, or pulmonary contusion on TCT were included. Patient groups analyzed included: 1) no injury (normal CXR, normal TCT, n = 1337); 2) occult injury (normal CXR, abnormal TCT, n = 205); and 3) overt injury (abnormal CXR, abnormal TCT, n = 227). Patients with overt injury required significantly more mechanical ventilation and had greater mortality than either occult or no injury patients. Occult and no injury patients had similar ventilator needs and mortality, but occult injury patients remained hospitalized longer. No patient with isolated occult thoracic injury required intubation or tube thoracostomy. Occult injuries, diagnosed by TCT only, have minimal clinical consequences but attract increased hospital resources.

Management of the crushed chest

Thoracic injuries are very common among trauma victims. This article reviews the current literature on the management of multiple aspects of the care of the patient with severe chest injury. The mechanics of chest injury are complex and varied. Chest wall injuries are the most common and noticeable manifestation of thoracic trauma. Overall morbidity and mortality are primarily determined by associated injuries. New ventilatory strategies permit oxygenation of the severely hypoxic patient. Acute pain management modalities offer the potential of decreasing associated pulmonary complications. Surgical chest wall fixation is clearly indicated in extreme cases of pulmonary herniation and chest wall disruption. There are potential benefits of surgical fixation in other settings, although further trials are needed.

Opening Pandora’s box: the potential benefit of the expanded FAST exam is partially confounded by the unknowns regarding the significance of the occult pneumothorax

Introduction

Point of care (POC) ultrasound brings another powerful dimension to the physical examination of the critically ill. A contemporary challenge for all care providers, however, is how to best incorporate ultrasound into contemporary algorithms of care. When POC ultrasound corroborates pre-examination clinical suspicion, incorporation of the findings into decision-making is easier. When POC ultrasound generates new or unexpected findings, decision-making may be more difficult, especially with conditions that were previously not appreciated with older diagnostic technologies. Pneumothoraces (PTXs), previously seen only on computed tomography and not on supine chest radiographs known as occult pneumothoraces (OPTXs), which are now increasingly appreciated on POC ultrasound, are such an example.

Methods

The relevant literature concerning POC ultrasound and PTXs was reviewed after an electronic search using PubMed supplemented by ongoing research by the Canadian Trauma Trials Collaborative of the Trauma Association of Canada.

Results

OPTXs are frequently encountered in the critically injured who often require mechanical ventilation with positive pressure breathing (PPB). Standard recommendations for post-traumatic PTXs and the setting of PPB mandate chest drainage, recognizing a significant rate of complications related to this procedure itself. Whether these standard recommendations generated in response to obvious overt PTXs apply to these more subtle OPTXs is currently unknown, and evidence-based recommendations regarding appropriate therapy are impossible due to the lack of clinical studies.

Conclusions

OPTXs are a condition that illustrates how incorporation of POC ultrasound findings brings further responsibilities to critically appraise the significance of these findings in terms of patient outcomes and overall care. Adequately powered and adequately followed-up clinical trials addressing the treatment are required.