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

Are Occult Pneumothoraces Truly Occult or Simply Missed?

BACKGROUND

Nonradiologists typically diagnose pneumothoraces (PTX) based on a visible pleural stripe. PTXs not seen on supine AP chest radiographs (CXR), but appreciated on a computed tomographic (CT) scan, termed occult pneumothoraces (OPTX), are increasingly common. The purpose was to (1) determine whether perceived OPTXs were truly occult or simply missed and (2) address factors that contribute to the poor sensitivity of the supine CXR.

METHODS

A previous study of severely injured patients (ISS >or =12) identified 44 patients with OPTXs. JPEG images of these CXRs were randomly arranged with images of 11 injured patients without PTXs (CT proven). Three unique groups of radiologists reviewed the images for signs of PTXs, and determined if a thoracic CT was subsequently required.

RESULTS

Retrospective review identified only 12 to 24% of the OPTXs depending on radiology group. The kappa inter-observer agreement value was 0.55 to 0.56 (poor agreement). PTXs were most commonly identified via the deep sulcus sign (75-90%). CXRs were considered inadequate in 16 to 25% of OPTX images and in 0 to 18% of images without OPTXs. Thoracic CT scans were recommended in 18 to 33% of patients with inadequate CXRs, but 67 to 82% of patients with adequate CXRs.

CONCLUSIONS

Less than 24% of all OPTXs might have been inferred from subtle radiologic findings, such as the deep sulcus sign. The majority of OPTX cases (50-64%) did not warrant a CT scan based on other findings. Concern for an OPTX after severe trauma is a valid indication for thoracic CT.

Diagnostic errors in polytrauma: a structured review of the recent literature

Clinically important diagnostic errors are relatively common among polytrauma patients (2-40%). Errors are not random; they are more frequent in the spine and periarticular appendicular skeleton, especially in hemodynamically unstable patients who require resuscitation or operative intervention before completion of secondary or tertiary clinical survey. Misleading history, distracting findings, and misjudgments all contribute to risks of diagnostic errors.

The Trauma Bay Chest Radiograph in Stable Blunt-Trauma Patients: Do We Really Need It?

The current study evaluates the need for trauma bay chest radiographs (CXR) in stable blunt-trauma patients who are scheduled for chest computed tomography (CCT). A retrospective review of 157 randomly selected, stable, adult blunt-trauma patients who were admitted to a level I trauma center between 2000 and 2002, who underwent both CXR and CCT (GE Light-Speed Scanner), was performed. Stable patients were defined as unintubated, normotensive (SBP >100 mm Hg), and without hypoxia (O2 saturation >90%). No interventions were conducted in the trauma bay based on chest radiograph findings. Among 95 patients with a “normal” CXR, 38 patients (40%) were found on CCT to have traumatic injuries. Among 62 patients with an “abnormal” CXR, 18 (29%) were found to be normal on CCT. Of the remaining 44 patients, 34 had additional findings on CCT. In 32 patients, CCT led to changes in management. CCT was more sensitive in diagnosing thoracic injuries and led to significant changes in management. We feel that CXR could be safely eliminated in favor of CCT in stable blunt-trauma patients.

Isolated computed tomography diagnosis of pulmonary contusion does not correlate with increased morbidity

BACKGROUND

Increased utilization of computed tomography (CT) has led to a rise in the diagnosis of pulmonary contusion. Its clinical significance, in the absence of findings on chest radiograph (CXR), has not been defined. This study examines the clinical course of patients with CT-only diagnosis of pulmonary contusion and compares it with that of patients with CXR-proven pulmonary contusion.

METHODS

The trauma database identified all children undergoing chest CT for blunt thoracic trauma during a 3-year period. Records were reviewed for age, mechanism of injury, Injury Severity Score (ISS), length of hospital stay (LOS), need for intensive care unit admission, and need for endotracheal intubation. A pediatric radiologist reviewed all films in a blinded fashion. Statistical analysis was performed using analysis of variance and Fisher's Exact test for 2 x 3 tables.

RESULTS

Eighty-two patients were identified. There were no CXR-positive, CT-negative cases. A CT diagnosis of pulmonary contusion was made in 46 patients. Of these, 31 had a contusion on CXR as well (CXR+ group) and 15 had a normal CXR (CT+ only group). Mean ISS score did not differ significantly between the two groups (27 +/- 12.3 and 22 +/- 10.3, respectively). Thirty-six patients had a normal CT (control). Mean LOS was significantly longer in the CXR+ group (13 +/- 12.0 days) than in the CT+ only and control groups (5 +/- 3.6 and 9 +/- 9.5 days, respectively; P < .01). The percentages of children requiring intensive care unit admission and intubation were also significantly higher in the CXR+ group.

CONCLUSION

The finding of pulmonary contusion by CT alone does not increase patient morbidity and appears to be of limited clinical significance.

Old fashion clinical judgment in the era of protocols: is mandatory chest X-ray necessary in injured patients?

BACKGROUND

The ATLS Course advocates that injured patients have a chest x-ray (CXR) to identify potential injuries. The purpose of this study was to correlate clinical indications and clinician judgment with CXR results to ascertain if a selective policy would be beneficial.

METHODS

Patients treated at a Level I trauma center over 12 months were prospectively evaluated. Before obtaining a CXR, signs, symptoms, and history suggestive of thoracic injury were identified. Additionally, a trauma surgeon (TS) recorded whether in their judgment a CXR was clinically indicated. These findings were compared with final CXR diagnoses. The sensitivity of individual clinical indicators, combinations of clinical indicators, and TS judgment for CXR abnormalities were calculated with a 95% confidence interval.

RESULTS

During the twelve-month study period, data were acquired on 772 patients (age 0-102 years). Seventy percent were male and 86.0% were injured by blunt force. Only 29% (N = 222) of the patients manifested one or more of the clinical indicators (signs and symptoms). The negative predictive value for the TS judgment was 98.2% which was superior to the clinical indicators. Reliance on the opinion of the TS to determine the need for a CXR would have eliminated 49.9% of CXRs and avoided hospital and radiologist reading charges totaling $100,078.22.

CONCLUSION

Mandatory CXR for all trauma patients has a low yield for abnormal findings. A selective policy relying on surgical judgment guided by clinical indicators is safe and efficacious while reducing cost and conserving resources.

Incidence, Risk Factors, and Outcomes for Occult Pneumothoraces in Victims of Major Trauma

BACKGROUND

The supine anteroposterior chest radiograph (CXR) is an insensitive test for posttraumatic pneumothoraces (PTXs). Computed tomographic (CT) scanning often detects PTXs that were not diagnosed on CXR (occult PTXs [OPTXs]). The purpose of this study was to define the incidence, predictors, and outcomes for OPTXs after trauma.

METHODS

Thoracoabdominal CT scans and corresponding CXRs of all trauma patients entered into a regional database were reviewed. Patients with OPTXs were compared with those with overt, residual, and no PTXs regarding incidence, demographics, associated injuries, early resuscitative predictors, treatment, and outcomes.

RESULTS

Paired CXRs and CT scans were available for 338 of 761 (44%) patients (98.5% blunt trauma). One hundred three PTXs were present in 89 patients, 57 (55%) of which were occult; 6 (11%) were seen only on thoracic CT scan. Age, sex, length of stay, and survival were similar between all groups. OPTXs and PTXs were similar in comparative size index and number of images. Subcutaneous emphysema, pulmonary contusion, rib fracture(s), and female sex were independent predictors of OPTXs. Seventeen (35%) patients with OPTXs were ventilated, of whom 13 (76%) underwent thoracostomy. No complications resulted from observation, although 23% of patients with thoracostomy had tube-related complications or required repositioning.

CONCLUSION

OPTXs are commonly missed both by CXR and even abdominal CT scanning in seriously injured patients. Basic markers available early in resuscitation are highly predictive for OPTXs and may guide management before CT scanning. Further study of OPTX detection and management is required.

Imaging of Acute Thoracic Injury: The Advent of MDCT Screening

Chest radiography remains the primary screening study for the assessment of victims of chest trauma, but computed tomography (CT), particularly multidetector CT (MDCT), has progressively changed the imaging approach to these patients. MDCT acquires thinner sections with greater speed, allowing higher quality axial images and nonaxial reformations than conventional or single-detector helical CT. The speed of MDCT, both in acquiring data and in reconstructing images, makes the performance of total body surveys in the blunt polytrauma patient practicable. In general, CT has been well documented to offer major advantages over chest radiography in both screening for thoracic injuries and in characterizing such injuries. This capacity has been enhanced by the application of multichannel data acquisition. The greater sensitivity of MDCT has been well demonstrated in diagnosing vascular and diaphragmatic injuries. This article reviews current concepts of diagnostic imaging in acute chest trauma from blunt force and penetrating mechanisms emphasizing the spectrum of diagnostic imaging findings for various injuries, based primarily on radiographic and CT appearances. The advantages of MDCT for selected injuries are emphasized.

Factors related to the failure of radiographic recognition of occult posttraumatic pneumothoraces

PURPOSE

Although posttraumatic pneumothoraces (PTXs) are common and potentially life threatening, the supine chest radiograph (CXR) is an insensitive test for their detection. Computed tomography (CT) often identifies occult pneumothoraces (OPTXs). Previous descriptions of OPTX topography have been poor. Our purpose was to define their distribution and aid in the targeting of thoracic ultrasound.

METHODS

Posttraumatic supine CXRs and CTs were reviewed for occult, overt, and residual PTXs. PTXs were compared according to their apical, basal, anterior, lateral, medial, and posterior components. A comparative size index was calculated.

RESULTS

Among 761 patients, 338 CT scans revealed 103 PTXs in 89 patients; 55% were OPTXs. OPTXs were apical (57%), basal (41%), anterior (84%), lateral (24%), and medial (27%), with 0% posterior.

CONCLUSIONS

CXR missed over half of all PTXs. OPTXs had a greater anterior versus lateral (nearly 4-fold) and both basal and apical versus lateral (2-fold) distribution. OPTXs are often located at easily accessible sonographic windows.

[Diagnosis and immediate therapeutic management of chest trauma. A systematic review of the literature]

OBJECTIVE

Injuries to the chest contribute significantly to the morbidity and mortality in multiple injured patients. This systematic review focuses on evidence based initial diagnostics and emergency room management of chest trauma.

METHODS

Clinical trials was systematically collected (Medline, Cochrane and hand searches) and classified into evidence levels (1 to 5 according to the Oxford system).

RESULTS

There are only a few studies that document the impact of injury mechanism and clinical examination of the patient. There is a positive correlation between crash severity or lateral impact with injury severity. Auscultation was found to be very sensitive in the detection of pneumothorax. Helical CT of the chest is most important in the initial work-up. Aortography is only indicated in selected cases. Whether tube thoracostomy is necessary in patients with occult pneumotharaces is still a matter of discussion. Indications for endotracheal intubation are poorly investigated and predominantly based on expert opinion.

CONCLUSION

Numerous comparative studies (LE 2) dealing with emergency diagnostics and therapy of chest trauma are available, however only a few randomized studies do exist. Based on the available data a rational therapy of chest trauma is possible.

Diagnostic imaging of acute thoracic injury

In recent years, the advent of multidetector CT (MDCT) has begun to change the imaging approach to patients sustaining blunt or penetrating thoracic injury. The ability to directly detect some injuries that are often occult on chest radiography, such as pericardial hemorrhage, major thoracic vascular injury, small pneumothorax, and diaphragm tears, as well as the ability to better define the extent of other injuries, such as lung contusion and laceration, account for this transition. This article reviews current concepts of diagnostic imaging in acute chest trauma from both blunt force and penetrating mechanisms, emphasizing the spectrum of diagnostic imaging findings for various injuries, primarily based on multidetector MDCT.

Pneumothorax

Spontaneous pneumothoraces can occur without obvious underlying lung disease (primary) or in patients with known underlying lung disease (secondary). Management guidelines for spontaneous pneumothorax have been published by major professional organizations, but awareness and application among clinicians seems poor. First episodes of primary spontaneous pneumothorax can be managed with observation if the pneumothorax is small. If the pneumothorax is large or if the patient is symptomatic, manual aspiration via a small catheter or insertion of a small-bore catheter coupled to a Heimlich valve or water-seal device, should be performed. In general, definitive measures to prevent recurrence are recommended after the first recurrence of the pneumothorax, and can be achieved by medical (e.g. talc) or surgical (video-assisted thoracic surgery) pleurodesis. Secondary pneumothoraces should be treated with chest tube drainage followed by pleurodesis after the first episode to minimize any risk of recurrence. Traumatic pneumothoraces may be occult (not seen on an initial CXR) or non-occult. The majority are treated by placement of a chest tube. Selected patients may be treated conservatively, with approximately 10% of these patients eventually requiring chest tube placement. Iatrogenic pneumothoraces have a myriad of causes with transthoracic lung needle biopsy being most common. Transthoracic needle biopsy-related pneumothoraces have CT findings that can predict their occurrence and the need for chest tube placement. Iatrogenic pneumothoraces, regardless of cause, may be managed by observation or small bore chest tube placement, depending upon patient stability and the size of the pneumothorax.

Hand-held thoracic sonography for detecting post-traumatic pneumothoraces: the Extended Focused Assessment with Sonography for Trauma (EFAST)

BACKGROUND

Thoracic ultrasound (EFAST) has shown promise in inferring the presence of post-traumatic pneumothoraces (PTXs) and may have a particular value in identifying occult pneumothoraces (OPTXs) missed by the AP supine chest radiograph (CXR). However, the diagnostic utility of hand-held US has not been previously evaluated in this role.

METHODS

Thoracic US examinations were performed during the initial resuscitation of injured patients at a provincial trauma referral center. A high frequency linear transducer and a 2.4 kg US attached to a video-recorder were used. Real-time EFAST examinations for PTXs were blindly compared with the subsequent results of CXRs, a composite standard (CXR, chest and abdominal CT scans, clinical course, and invasive interventions), and a CT gold standard (CT only). Charts were reviewed for in-hospital outcomes and follow-up.

RESULTS

There were 225 eligible patients (207 blunt, 18 penetrating); 17 were excluded from the US examination because of battery failure or a lost probe. Sixty-five (65) PTXs were detected in 52 patients (22% of patients), 41 (63%) being occult to CXR in 33 patients (14.2% whole population, 24.6% of those with a CT). The US and CXR agreed in 186 (89.4%) of patients, EFAST was better in 16 (7.7%), and CXR better in 6 (2.9%). Compared with the composite standard, the sensitivity of EFAST was 58.9% with a likelihood ratio of a positive test (LR+) of 69.7 and a specificity of 99.1%. Comparing EFAST directly to CXR, by looking at each of 266 lung fields with the benefit of the CT gold standard, the EFAST showed higher sensitivity over CXR (48.8% versus 20.9%). Both exams had a very high specificity (99.6% and 98.7%), and very predictive LR+ (46.7 and 36.3).

CONCLUSION

EFAST has comparable specificity to CXR but is more sensitive for the detection of OPTXs after trauma. Positive EFAST findings should be addressed either clinically or with CT depending on hemodynamic stability. CT should be used if detection of all PTXs is desired.

Infrared thermography: a rapid, portable, and accurate technique to detect experimental pneumothorax

RATIONALE AND OBJECTIVE

Pneumothorax (Ptx) is a life-threatening complication that can result from trauma, mechanical ventilation, and invasive procedures. Infrared thermography (IRT), a compact and portable technology, has become highly sensitive. We hypothesized that IRT could detect Ptx by identifying associated changes in skin temperature.

MATERIALS AND METHODS

Bilateral nonpenetrating chest incisions or needle punctures were performed in 21 anesthetized rats. Rats were then randomized to no, bilateral, left, or right Ptx by either open (n = 16) or closed percutaneous (n = 5) puncture through selected pleurae. Real-time thermographic images and surface temperature data were acquired with a noncooled infrared camera.

RESULTS

In all cases, blinded observers correctly identified each Ptx with real-time grayscale image analysis. When compared to either the ipsilateral baseline or an abdominal reference, experimental Ptx produced a significantly greater decrease in surface temperature when compared to non-Ptx control.

CONCLUSIONS

These results demonstrate that portable infrared imaging can rapidly and accurately detect changes in thoracic surface temperature associated with experimental pneumothorax.

The diagnosis and management of children with blunt injury of the chest

Thoracic trauma remains a major source of morbidity and mortality in injured children, and is second only to brain injuries as a cause of death. The presence of a chest injury increases an injured child's mortality by 20-fold. Greater than 80% of chest injuries in children are secondary to blunt trauma. The compliant chest wall in children makes pulmonary contusions and rib fractures the most common chest injuries in children. Injuries to the great vessels, esophagus, and diaphragm are rare. Failure to promptly diagnose and treat these injuries results in increased morbidity and mortality.

Blunt thoracic trauma: flail chest, pulmonary contusion, and blast injury

Blunt thoracic trauma can result in significant morbidity in injured patients. Both chest wall and the intrathoracic visceral injuries can lead to life-threatening complications if not anticipated and treated. Pain control, aggressive pulmonary toilet, and mechanical ventilation when necessary are the mainstays of supportive treatment. The elderly with blunt chest trauma are especially at risk for pulmonary deterioration in the several days postinjury and should be monitored carefully regardless of their initial presentation. Blunt thoracic trauma is also a marker for associated injuries, including severe head and abdominal injuries.

Imaging of chest trauma: radiological patterns of injury and diagnostic algorithms

In patients after chest trauma, imaging plays a key role for both, the primary diagnostic work-up, and the secondary assessment of potential treatment. Despite its well-known limitations, the anteroposterior chest radiograph remains the starting point of the imaging work-up. Adjunctive imaging with computed tomography, that recently is increasingly often performed on multidetector computed tomography units, adds essential information not readily available on the conventional radiograph. This allows better definition of trauma-associated thoracic injuries not only in acute traumatic aortic injury, but also in pulmonary, tracheobronchial, cardiac, diaphragmal, and thoracic skeletal injuries. This article reviews common radiographic findings in patients after chest trauma, shows typical imaging features resulting from thoracic injury, presents imaging algorithms, and recalls to the reader less common but clinically relevant entities encountered in patients after thoracic trauma.

Prospective validation of computed tomographic screening of the thoracolumbar spine in trauma

OBJECTIVE

Concern for thoracolumbar spine (TLS) injuries after major trauma mandates immobilization pending radiographic evaluation. Current protocols use standard posteroanterior and lateral radiographs of the thoracolumbar spine (XR/TLS), but many patients also undergo abdominal or thoracic computed tomographic (CT) scanning. We sought to evaluate whether helical truncal CT scanning performed to evaluate visceral trauma images the spine as well as dedicated XR/TLS.

METHODS

We prospectively studied 222 consecutive patients sustaining high-risk trauma requiring TLS screening because of clinical findings or altered mentation. The chest, abdomen, and pelvis were imaged with one intravenous contrast infusion. All patients had CT scan of the chest, abdomen, and pelvis (CT/CAP) and XR/TLS. Initial radiologic diagnoses were compared with the discharge diagnosis of acute fractures confirmed by thin-cut CT scan and/or clinical examination of the patient when alert.

RESULTS

Of 222 patients studied, 215 were fully evaluated. Thirty-six (17%) had acute TLS fractures. The accuracy of CT/CAP for TLS fractures was 99% (95% confidence interval [CI], 96-100%). The accuracy of XR/TLS was 87% (95% CI, 82-92%). Sensitivity, specificity, and positive and negative predictive values were better for CT/CAP than for XR/TLS. CT/CAP found acute fractures XR/TLS missed, and correctly classified old fractures XR/TLS read as "possibly" acute. The total XR/TLS misclassification rate was 12.6% (95% CI, 8.4-19%); for CT/CAP it was 1.4% (95% CI, 0.3-3.3%). No fractures were missed by CT/CAP. No unstable fracture was missed by either technique.

CONCLUSION

CT/CAP diagnoses TLS fractures more accurately than XR/TLS. Neither misses unstable fractures, but CT scanning finds small fractures that benefit by treatment and identifies chronic disease better. CT screening is far faster and shortens time to removal of spine precautions. CT scan-based diagnosis does not result in greater radiation exposure and improves resource use. Screening the TLS on truncal helical CT scanning performed for the evaluation of visceral injuries is more accurate than TLS imaging by standard radiography. CT/CAP should replace plain radiographs in high-risk trauma patients who require screening.

What size chest tube? What drainage system is ideal? And other chest tube management questions

Chest tubes and their accompanying pleural drainage units continue to present challenging questions regarding their optimal use. Appropriate chest tube size selection to accommodate the clinical situation is key, especially in the setting of large pleural air leaks lest a tension pneumothorax ensue. Connection of an appropriate pleural drainage unit to the chest tube is equally important to obviate impeding airflow after successful evacuation by the chest tube. Large-bore chest tubes are generally required for patients with pneumothoraces, regardless of etiology, if the patient is mechanically ventilated, or for patients requiring drainage of viscous pleural liquids such as blood. Smaller bore tubes may be adequate in patients with limited production of pleural air or of free-flowing pleural liquid. Chest tubes may be removed successfully at either end expiration or end inspiration, and potentially as soon as </=200 mL/fluid output per day is achieved. Additional prospective studies are needed to provide evidence-based answers to the many questions remaining regarding chest tube placement, ongoing management, and removal.

Multislice CT in thoracic trauma

The introduction of CT imaging in the 1970s revolutionized all aspects of medical care, perhaps nowhere more so than in the evaluation of acutely injured patients. Just as single-slice helical scanning was a great advance over conventional CT, the capabilities of MSCT are proving to be dramatically superior to single-slice methods. Improved contrast bolus imaging, thinner slices, and isotropic voxels should enable the trauma radiologist to identify both major organ system disruption and subtle injuries more promptly. Multiplanar and three-dimensional reconstructions, a forte of MSCT, facilitate rapid communication of disease states with surgeons and others involved in the care of injured patients. In many centers, whole-body CT is beginning to supplant plain films of the chest and spine in the evaluation of severe trauma victims; the cost-effectiveness of such methods is still under evaluation.

[Lung contusion: relevance of initial injured pulmonary volume measurement by computed tomography]

OBJECTIVE

To evaluate computed tomography quantification of injured pulmonary volume after thoracic trauma and its relevance for severity grade of patients with lung contusion.

STUDY DESIGN

Retrospective study in a major French Level I university trauma center.

PATIENTS AND METHODS

Clinical and biological data including oxygenation index (PaO2/FIO2) and therapeutics modalities during the first 5 days: positive end expiratory pressure (Peep) and nitric oxide (NO), were collected on 49 patients with lung contusion resulting from thoracic trauma. Injured pulmonary volume was evaluated on initial thoracic tomodensitometry by 2 senior radiologists. The correlation between oxygenation index, therapeutics modalities and initial injured pulmonary volume was assessed for signification.

RESULTS

Injured pulmonary volume larger than 37.75% of total lung volume is associated with both hypoxemia at the twenty-fourth hour (PaO2/FIO2 <300), and need for Peep >6 cm H2O and /or ongoing NO administration on day 5.

CONCLUSION

Injured parenchymal pulmonary volume evaluation on initial tomodensitometry seems to be an important indicator of lung contusion severity. Thoracic computed tomography provides additional prognostic information in the initial evaluation of thoracic trauma with parenchymal injury.

Should helical CT scanning of the thoracic cavity replace the conventional chest x-ray as a primary assessment tool in pediatric trauma? An efficacy and cost analysis

BACKGROUND/PURPOSE

Findings from studies in the trauma literature suggest that thoracic computed tomography (TCT) scanning should replace conventional radiographs as an initial imaging modality. Limited data exist on the clinical utility and cost of TCT scans in pediatric trauma. Our current practice is to obtain TCT scans in those children at risk for thoracic injures. The purpose of this study is to examine what additional information TCT provides, how frequently it results in a change in clinical management, and a cost/benefit analysis.

METHODS

Children 18 years old and younger that had both a Chest x-ray (CXR) and TCT scan in their initial workup were included. Indications for TCT scan were (1) any sign of thoracic injury on CXR, (2) pathologic findings on physical examination of the chest, and (3) high impact force to chest wall. A child may have had one or more indications for a TCT scan.

RESULTS

Between 1996 and 2000, 45 of 1,638 trauma patients met study criteria. Indications for TCT included thoracic injury on CXR (n = 27), findings on physical examination (n = 8) and high-impact force (n = 33). In 18 of the 45 (40%), injuries were detected with TCT imaging but not on CXR. These included contusions (n = 12), hemothorax (n = 6), pneumothorax (n = 5), widened mediastinum (n = 4), rib fractures (n = 2), diaphragmatic rupture (n = 1), and aortic injury (n = 1). In 8 patients (17.7%) TCT imaging resulted in a change in clinical management. These included insertion of a chest tube (n = 5) aortography (n = 2) and operation (n = 1). Age, sex, injury severity score, mechanism, and indication for TCT could not predict differences between TCT and CXR (P >.05). In our institution, the cost of a TCT is $200, and the patient charge is $906 ($94 per CXR). Based on our study data 200 TCTs would need to be done for each clinically significant change, increasing patient ($180,000) and hospital ($39,600) costs.

CONCLUSIONS

Helical TCT is a highly sensitive imaging modality for the thoracic cavity; however, routine CXR still provides clinically valuable information for the initial trauma evaluation at minimal cost. TCT should be reserved for selected cases and not as a primary imaging tool.

Influence of medical speciality and experience on interpretation of helicoidal thoracic computed tomography in blunt chest trauma

OBJECTIVE

To compare the quality of interpretation of chest helicoidal computed tomography (HCT) by physicians with different levels of experience and medical specialty.

DESIGN

Prospective observational study.

SETTING

Trauma critical care unit at a French university hospital (US equivalent: level 1).

PATIENTS

HCT of 50 consecutive patients with blunt chest trauma were assessed by four groups of physicians [residents in anaesthesiology (n=5), residents in radiology (n=5), senior anaesthesiologists (n=5), and senior radiologists (n=5)]. Interpretation from each physician was compared with a grid obtained from an expert interpretation by a senior radiologist and a senior anaesthesiologist.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

No group of observers performed better than another in their interpretation of lung and parietal injuries on HCT. In contrast, senior radiologists were better than anaesthesiologists for the diagnosis of pneumomediastin. However, residents in radiology performed better than other physicians in detecting the presence of gastric and tracheal tubes.

CONCLUSIONS

Compared with anaesthesiologists, senior radiologists seem more expert in the diagnosis of HCT mediastinal injuries whereas residents in radiology were better at detecting resuscitation materials in thoracic trauma patients. This article reinforces the usefulness of the interpretation of the HCT by a senior radiologist in the case of blunt chest trauma. This also reinforces the usefulness of an aspect team of radiologists and anaesthesiologists in the case of trauma. The logical usefulness of a systematic interpretation of the images should be borne in mind.

Do we really need routine computed tomographic scanning in the primary evaluation of blunt chest trauma in patients with "normal" chest radiograph?

BACKGROUND

A major cause of morbidity and mortality after blunt chest trauma remains undetected injuries. This study evaluates the role of routine computed tomographic (CT) scan.

METHODS

We studied 93 consecutive patients from January 1999 to July 2000: 73 (76.3%) after motor vehicle crash with crash speed > 10 mph, and 22 (23.7%) after fall from height > 5 ft. Simultaneous with initial clinical evaluation, anteroposterior chest radiograph and helical chest CT scan were obtained for all patients.

RESULTS

Sixty-eight patients (73.1%) showed at least one pathologic sign on chest radiograph, and 25 patients (26.9%) had normal chest radiograph. In 13 (52.0%) of these 25 patients, the CT scan showed multiple injuries; among these were two aortic lacerations, three pleural effusions, and one pericardial effusion.

CONCLUSION

Over 50% of patients with normal initial chest radiograph showed multiple injuries on the CT scan, among which were also two (8%) potentially fatal aortic lesions. We therefore recommend primary routine chest CT scan in all patients with major chest trauma.

A population-based study on pneumothorax in severely traumatized patients

BACKGROUND

Pneumothorax (PNX) is a recognized cause of preventable deaths in trauma patients. Our objective was to determine the incidence of traumatic PNX, the characteristics of its victims, and the treatment they receive.

METHODS

The study consisted of data set of a population-based study on major trauma.

RESULTS

The incidence of PNX was 81 per 1 million population per year, mostly caused by transport accidents. PNX victims generally had multiple injuries, and they showed on-scene clinical parameters worse than victims of other chest injuries of comparable severity. Fifty-three percent of PNXs were drained during the prehospital and early (< 2 hours) hospital course. There was no uniformity of treatment among different types of rescue facilities, some of them never performing decompression despite clinical need. The z statistic for mortality was -0.63.

CONCLUSION

PNX can be expected in one in five major trauma victims found alive. PNX is associated with a peculiar on-scene instability. Early decompression is often required. The effects of wider access to prehospital decompression and the reasons for its uneven availability in our setting need elucidation. Nevertheless, the present mortality follows the international standards.

Using CT to diagnose tracheal rupture

OBJECTIVE

A retrospective study was performed to assess CT sensitivity for diagnosing tracheal rupture. Intubated cadaver tracheas were examined to assess endotracheal tube balloon overdistention and deformity and to evaluate the relationship of balloon pressures to tracheal injury.

MATERIALS AND METHODS

Neck or chest CT scans of 14 patients with tracheal rupture and 41 control trauma patients with pneumomediastinum but without tracheal injury were reviewed and compared to assess the presence and location of extrapulmonary air, whether direct visualization of tracheal wall disruption was possible, the size and shape of endotracheal tube balloon, signs of transtracheal balloon herniation in intubated patients, and the location of the extratracheal endotracheal tube. Intact and experimentally injured cadaver tracheas were used to evaluate tube balloon pressure and configuration.

RESULTS

All 14 patients with tracheal rupture had deep cervical air and pneumomediastinum. Overdistention of the tube balloon occurred in 71% (5/7) of the intubated patients, and balloon herniation occurred in 29% (2/7). Direct tracheal injury was seen in 71% (10/14) of the patients as a wall defect (n = 8) or deformity (n = 2). Overall, CT was 85% sensitive for detecting tracheal injury. Patients with tracheal injury had a significantly lower incidence of pneumothorax (p = 0.01) than did the control group. The CT appearance of balloon herniation through defects in the cadaver tracheas closely mimicked those of patients with tracheal injury. The amount of balloon pressure required to rupture the intubated trachea was extremely high and rupture was difficult to obtain.

CONCLUSION

CT can reveal tracheal injury and can be used to select trauma patients with pneumomediastinum for bronchoscopy, leading to early confirmation and treatment.

Detection of occult pneumothoraces on abdominal computed tomographic scans in trauma patients

BACKGROUND

An unrecognized, or occult, injury is particularly dangerous in trauma patients, who often have multiple life-threatening injuries. We sought to determine the frequency and quantify the utility of the abdominal computed tomographic (CT) scan in detecting occult pneumothoraces.

METHODS

Charts of all trauma patients diagnosed with a pneumothorax over a 7-year period were retrospectively reviewed for findings on admission chest radiograph, abdominal CT scan, and other demographic data.

RESULTS

A total of 312 charts were reviewed, with 230 patients identified as having a pneumothorax at admission. Of the 230 patients, 126 (54.8%) had an occult pneumothorax identified on abdominal CT scan. In these patients, the mean Trauma Score was 14.1 +/- 2.9 and the mean Injury Severity Score was 24.1 +/- 11.2. In the group of occult pneumothoraces, 84 (66.7%) underwent chest tube placement.

CONCLUSIONS

Abdominal CT scanning provided important information about thoracic trauma often missed on initial evaluation in the trauma bay. This information frequently affected the patient's clinical management.

Tertiary survey of the trauma patient in the intensive care unit

The issues surrounding the arrival of trauma patients to the ICU have been defined. By necessity, many of these topics are dealt with elsewhere in greater detail. The basic framework within which this phase of care could be optimized has been provided. Pitfalls related to patients' mode of arrival to the ICU affect subsequent management and should direct specific clinical activity. The tertiary survey is a complete summation and cataloguing of a patient's injuries. The need for ongoing resuscitation determines how much attention can be paid to the tertiary survey. Clinical suspicion based on mechanism and pattern of injury and thorough, repeated, complete physical examination are the essential elements of the tertiary survey. The survey is affected by factors that alter patients' mental status because examination is most reliable in patients who can localize pain. Medications, intoxication, and head injuries are common factors that interfere with the reliability of the tertiary survey for variable periods. Radiographic assessment is used to identify injuries suspected on the basis of mechanism of injury, injury pattern, and findings on physical examination. Some studies may be done portably; others require transport within the hospital. The intensivist must prioritize these ongoing diagnostic studies based on patient stability and the need for ongoing resuscitation.

Evaluation of the utility of computed tomography in the initial assessment of the critical care patient with chest trauma

OBJECTIVE

To determine the utility of thoracic computed tomography (TCT) in the initial assessment of critically ill patients with chest injuries.

DESIGN

Prospective observational study of cohorts.

SETTING

Trauma intensive care unit (ICU) of a Spanish Level III hospital (US equivalent Level I).

PATIENTS

Three hundred seventy-five patients with chest injuries were studied, grouped into two cohorts according to whether they underwent admission TCT (exposed cohort, group I, n = 104) or not (unexposed cohort, group II, n = 271).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographic data, initial severity scores, and chest radiograph (CXR)-based diagnosis were collected in all patients as independent variables. In patients of group I, we also recorded the TCT-based diagnosis and any incidents, complications, or therapy changes resulting from the TCT. The need for and duration of mechanical ventilation, length of ICU stay, and ICU mortality were gathered in the whole sample as dependent variables. The admission data were similar in the two groups, except for a higher Injury Severity Score (ISS) and thoracic ISS in group I. TCT proved to be more sensitive than CXR in detecting pulmonary contusion, hemothorax, pneumothorax, and vertebral fractures and in identifying the faulty placement of chest drainage tubes. TCT findings induced therapy changes in approximately 30% of patients in group I. In the other dependent variables studied, there were no differences between the two groups. In the multivariate analysis, the TCT screening had no effects on the time on mechanical ventilation, length of ICU stay, or mortality.

CONCLUSIONS

TCT detects more chest injuries in trauma patients than does CXR and induces therapy changes in a considerable number of patients. However, this does not translate into an improvement in clinical outcomes.

Radiographic and CT findings in blunt chest trauma

Injuries of the thorax are a major cause of morbidity and mortality in blunt trauma patients. Radiologic imaging plays an important role in the workup of the patient with thoracic trauma. The chest radiograph is the initial imaging study obtained, but computed tomography (CT) is now used frequently in the evaluation of chest trauma. The primary role of chest CT has been to assess for aortic injuries, but CT has been shown to be useful for the evaluation of pulmonary, airway, skeletal, and diaphragmatic injuries as well. Magnetic resonance imaging (MRI) has a limited role in the initial evaluation of the trauma patient, but may be of use for the evaluation of the spine and diaphragm in patients who are hemodynamically stable.

Efficiency of chest computed tomography in critically ill patients with multiple traumas

OBJECTIVE

The efficiency of secondary thoracic computed tomography (TCT) in critically ill patients with multiple traumas was assessed by comparison of TCT with chest radiograph findings. The subsequent therapeutic consequences based on the additional information of TCT were evaluated.

SETTING

A six-bed trauma intensive care unit in a university hospital.

DESIGN

Prospective, descriptive study.

PATIENTS AND INTERVENTIONS

One hundred one computed tomographic (CT) examinations (mean, 2.6 per patient; range, 1-10) were performed in 39 patients, fulfilling the following indications for TCT: a) sepsis with suspected pulmonary focus (n = 41); b) deterioration of pulmonary gas exchange (n = 35); c) guiding the duration of intermittent prone positioning (n = 25). The information provided by TCT was compared with corresponding chest radiographs (CXR). Therapeutic consequences drawn after TCT were compared with the additional diagnostic information of TCT. The change of therapy was documented that would not have been undertaken or may have been delayed had TCT evaluation not been used.

RESULTS

TCT was significantly superior to CXR in detecting pneumothoraces, pleural effusions, and pulmonary abscesses. Furthermore, a significantly higher accuracy regarding pulmonary densities was found. Subsequent therapeutic interventions ensued from 85 (84.2%) CT scans. After TCT, intermittent prone positioning was initiated in 31 patients, chest tubes were inserted in 16 patients, and intermittent prone positioning was terminated in 13 patients and was continued in 12 patients. Eleven thoracotomies were performed because of the TCT findings. The described therapeutic interventions were based on abnormalities seen on CT scans but were not evident in CXR in 58 patients (57.4%). Significant information that influenced therapeutic concepts was obtained in 66% (n = 23) of patients with pulmonary deterioration of gas exchange, in 61% (n = 25) of patients with sepsis, and in 40% (n = 10) of patients to guide the duration of intermittent prone positioning. Thoracotomy and specific drainage by tube thoracostomy was always dependent on the findings of TCT.

CONCLUSION

Performed under the above displayed defined indications, TCT had an overall efficiency of 57%. It provided an increased sensitivity for intrathoracic lesions and a more comprehensive diagnosis of chest abnormalities.

Imaging in thoracic trauma: the trauma surgeon's perspective

Thoracic trauma is a common cause of significant disability and mortality. Most thoracic injury in developed countries results from motor vehicle crashes (MVC). Imaging of patients with thoracic trauma must be accurate and timely to avoid preventable death. Trauma surgeons prioritize imaging options based on the patient's hemodynamic status, associated injuries, and age. The screening test for the detection of life-threatening thoracic injury is the supine anteroposterior (AP) chest radiograph. Rib fractures are a marker for serious associated injuries, including abdominal injuries. Rib fractures are especially ominous in children and the elderly. Thoracic aortic injury is associated with high-speed mechanisms of injury and can occur in the absence of radiographic signs. Chest computed tomography (CT) can be used as a screening and diagnostic tool for suspected aortic injury. Aortography is reserved for patients with high suspicion of aortic injury or for confirmation of CT scan diagnosis.

Advances in the diagnosis and treatment of thoracic trauma

With the exception of the use of ECG to screen patients for blunt cardiac injury, recent advances in the diagnosis of thoracic trauma involve new technology. Use of surgeon-performed pericardial and pleural ultrasound for the detection of tamponade or hemothorax, TEE or spiral CT to diagnose rupture of the thoracic aorta, and thoracoscopy to evaluate a hemothorax or the integrity of the left hemidiaphragm are all standard techniques in modern trauma centers. In terms of treatment, emergency center thoracotomy is performed more selectively and with the adjunct of staple closure for cardiac wounds. Pulmonotomy is used selectively to control deep lobar hemorrhage and to avoid the need for an emergent lobectomy. Finally, nonoperative management of an intimal tear of the thoracic aorta or delayed operative management of a full-thickness tear in the patient with multiple injuries, using beta-blocker-induced relative hypotension, is rapidly becoming the standard of care throughout the United States.

Imaging diagnosis of nonaortic thoracic injury

Chest radiographs remain the initial imaging modality to rapidly screen patients with blunt chest trauma. Spiral CT is more sensitive and specific in diagnosing most thoracic pathology seen in blunt trauma patients. This article reviews the major clinical and radiologic findings that occur with blunt injuries to the chest, excluding mediastinal vascular injuries.

Helical CT grading of traumatic aortic injuries. Impact on clinical guidelines for medical and surgical management

Helical CT is a reliable method for screening patients with blunt chest trauma for vascular and visceral injuries. Thoracic aortic injuries detected by CT examination affect the immediate clinical management and patient triage. This article describes the clinical indications and imaging protocols for helical CT of the chest used to detect aortic injuries, provides a grading system of the range of aortic injuries demonstrated by CT, and discusses the clinical management decisions that should be considered based on the CT grade of the aortic injury.

Evaluation of the patient with blunt chest trauma: an evidence based approach

The patient who has sustained blunt trauma to the chest can present a diagnostic challenge to the emergency physician. There are several diagnostic modalities available for treating life-threatening injuries to these patients. The authors review published studies to support the use of these tests in diagnosing injuries from blunt thoracic trauma. The article focuses chiefly on two current areas of controversy, the diagnosis of blunt aortic and blunt myocardial injury. Finally, the authors make recommendations for the use of various tests based on the available evidence.

Improvement in the therapy of multiply injured patients by introduction of clinical management guidelines

A trauma algorithm representing the guidelines for the management of emergency treatment of severe blunt trauma was implemented at our institution in 1994. By comparison of two prospectively recorded cohorts of multiply injured patients, the clinical efficacy of these guidelines was analysed. The algorithm cohort comprised 74 patients over the period January 1994 to June 1996, and the Control cohort 126 patients over the period April 1988 to December 1993. To evaluate procedural quality of early clinical trauma management, nine criteria were applied. After implementation of the algorithm there was an improvement in all parameters reflected by a significant reduction of missed injuries and important time savings. Mortality rates in the cohorts were calculated after subdivision into three groups (I-III) with moderate (ISS: 18-24), high (ISS: 25-49) and very high (ISS: 50-75) injury severity. All cohort subgroups were comparable with respect to ISS values, age, initial loss of consciousness (GCS) and shock rate. In all subgroups of the algorithm cohort mortality rates were reduced: group I: 0 versus 20 per cent (p < 0.05); group II: 8 versus 24 per cent (p < 0.05); group III: 40 versus 71 per cent. Improvements in both therapeutic process and outcome were observed after implementation of the trauma algorithm.