Pulmonary contusion: review of the clinical entity

Pulmonary contusion is a common lesion occurring in patients sustaining severe blunt chest trauma. Alveolar hemorrhage and parenchymal destruction are maximal during the first 24 hours after injury and then usually resolve within 7 days. The diagnosis of traumatic lung injury is usually made clinically with confirmation by chest x-ray films. The chest computed tomography scan is highly sensitive in identifying pulmonary contusion and may help predict the need for mechanical ventilation. Respiratory distress is common after lung trauma, with hypoxemia and hypercarbia greatest at about 72 hours. Although management of patients with pulmonary contusion is supportive, pneumonia and adult respiratory distress syndrome with long-term disability occur frequently.

Classification of parenchymal injuries of the lung

Pulmonary contusion, implying interstitial and alveolar injury without significant laceration, has been accepted as the primary lung injury in nonpenetrating chest trauma. Computed tomographic (CT) findings were compared with those of chest radiography in 85 consecutive patients with chest trauma in which there was a pulmonary radiodensity consistent with pulmonary contusion or patients with a history of severe chest trauma with normal parenchyma despite rib fractures, hemothorax, pneumothorax, or widened mediastinum. CT was found to be more sensitive than radiography in that 151 abnormalities (excluding rib fractures) were demonstrated on radiographs versus 423 abnormalities on CT scans, and 99 lacerations were seen on CT scans versus five on radiographs. Pulmonary lacerations were classified into four types on the basis of CT findings and mechanism of injury: compression rupture, compression shear, rib penetration, and adhesion tears. In these cases, pulmonary laceration was shown to be an integral component of the mechanism of injury in pulmonary contusion, pulmonary hematoma, pulmonary cyst or pneumatocele, or cavitation in pulmonary contusion.

Chest Ultrasonography in Lung Contusion

STUDY OBJECTIVE

Despite the high prevalence of chest trauma and its high morbidity, lung contusion (LC) often remains undiagnosed in the emergency department (ED). The present study investigates the possible clinical applicability of chest ultrasonography for the diagnosis of LC in the ED in comparison to radiography and CT.

MATERIALS AND METHODS

One hundred twenty-one patients admitted to the ED for blunt chest trauma were investigated using ultrasonography by stage III longitudinal scanning of the anterolateral chest wall to detect LC. Data were retrospectively collected in an initial series of 109 patients (group 1) and prospectively in the next 12 patients (group 2). All patients who presented with pneumothorax were excluded. After the ultrasound study, all patients were submitted to chest radiography (CXR) and CT. The sonographic patterns indicative of LC included the following: (1) the alveolointerstitial syndrome (AIS) [defined by increase in B-line artifacts]; and (2) peripheral parenchymal lesion (PPL) [defined by the presence of C-lines: hypoechoic subpleural focal images with or without pleural line gap].

RESULTS

The diagnosis of LC was established by CT scan in 37 patients. If AIS is considered, the sensitivity of ultrasound study was 94.6%, specificity was 96.1%, positive and negative predictive values were 94.6% and 96.1%, respectively, and accuracy was 95.4%. If PPL is alternatively considered, sensitivity and negative predictive values drop to 18.9% and 63.0%, respectively, but both specificity and positive predictive values increased to 100%, with an accuracy of 65.9%. Radiography had sensitivity of 27% and specificity of 100%.

CONCLUSIONS

Chest ultrasonography can accurately detect LC in blunt trauma victims, in comparison to CT scan.

Diagnosing cardiac contusion: old wisdom and new insights

Cardiac contusion is usually caused by blunt chest trauma and therefore is frequently suspected in patients involved in car or motorcycle accidents. The diagnosis of a myocardial contusion is difficult because of non-specific symptoms and the lack of an ideal test to detect myocardial damage. Cardiac contusion can cause life threatening arrhythmias and cardiac failure. Many diagnostic methods, such as ECG, biochemical cardiac markers, transthoracic and transoesophageal echocardiography, and radionuclide imaging studies, have been investigated to determine their use in predicting such complications. Recently, cardiac troponin I and T were found to be highly sensitive for myocardial injury. Troponin I and T have also proved to be useful in the stratification of patients at risk for complications. Nevertheless, diagnosis of a cardiac contusion and identification of patients at risk remain a challenge. In this review the current diagnostic tests will be discussed. Also, based on these diagnostic tests, a screening strategy containing data from the latest studies is presented, with the intention of detecting patients at risk.

Evaluation of noninvasive tests of cardiac damage in suspected cardiac contusion

Nonpenetrating trauma to the chest can result in cardiac damage that may be overlooked because of associated injuries and the lack of obvious thoracic injury. The clinical diagnosis of important cardiac damage in this setting is difficult. We evaluated noninvasive tests for detecting myocardial damage in 100 patients with severe, nonpenetrating chest trauma. The noninvasive tests included serial ECG, serial total CPK and CPK-MB enzymes, continuous Holter monitor recording to detect dysrhythmia, and technetium-99m pyrophosphate scintigraphy. Peak CPK-MB elevations occurred in 72 patients. ECG abnormalities were noted in 70 patients, and 27 patients had Lown grade 3 or greater dysrhythmias. Fifteen patients died and all had autopsies. The noninvasive abnormalities were nonspecific and did not reflect myocardial contusion that led to clinically important cardiac complications.

CT criteria for management of blunt liver trauma: correlation with angiographic and surgical findings

PURPOSE

To determine the contrast material-enhanced computed tomographic (CT) criteria for selection of hemodynamically stable patients with blunt hepatic injury for angiographic evaluation.

MATERIALS AND METHODS

Seventy-two patients with blunt liver injury underwent CT and hepatic angiography. Hepatic injuries were graded with CT-based classification. Scans were assessed for evidence of contrast extravasation and laceration or contusion extending into the hepatic vein(s), inferior vena cava, porta hepatis, or gallbladder fossa. Medical, angiographic, and surgical records were reviewed to determine angiographic findings, surgical indications and findings, and outcomes.

RESULTS

Compared with hepatic angiography, CT was 65% (11 of 17 patients) sensitive and 85% (41 of 48 patients) specific for detection of arterial vascular injury. When CT severity grades 2 and 3 were analyzed, the sensitivity and specificity of CT were 100% (three of three patients) and 94% (34 of 36 patients), respectively (P <.001). Injury involving at least one major hepatic vein was found in 15 (88%) of 17 patients who required liver-related surgery and in 23 (42%) of 55 of the other patients (P <.01).

CONCLUSION

CT-based criteria, including hepatic injury grade, signs of arterial vascular injury, and presence or absence of major hepatic venous involvement assists in selecting patients for hepatic angiography and those at increased risk of ongoing or delayed hepatic bleeding or other posttraumatic complications.

Operative chest wall stabilization in flail chest--outcomes of patients with or without pulmonary contusion

BACKGROUND

The aim of operative chest wall stabilization in patients with flail chest and respiratory insufficiency is to reduce ventilator time and avoid ventilator associated complications. The purpose of this retrospective study was to analyze the indications and outcomes of operative chest wall stabilization in defined groups of patients sustaining flail chest with and without pulmonary contusion.

METHODS

The hospital records of 405 patients with multiple trauma (Injury Severity Score > 17) between 1988 and 1994 were reviewed. Forty-two patients sustained flail chest. Twenty of these underwent operative chest wall stabilization for the following indications: 1) flail chest with indication for thoracotomy due to intrathoracic injury (n = 6); 2) flail chest without pulmonary contusion (n = 9); 3) paradoxical movement of a chest wall segment in the weaning period from the respirator (n = 3); and 4) severe deformity of the chest wall (n = 2). For the purpose of analysis the patients were separated into groups: group 1: operative chest wall stabilization in flail chest without pulmonary contusion (n = 10); group 2: operative chest wall stabilization in flail chest with pulmonary contusion (n = 10); group 3: flail chest without pulmonary contusion and without chest wall stabilization (n = 18); group 4: flail chest with pulmonary contusion and without chest wall stabilization (n = 4). Data were coded for time of operation, duration of ventilatory support, and complications.

RESULTS

There were no significant differences in age, severity of injury, and extent of injury between groups 1, 2, and 3 (p < 0.42). Group 4 was excluded for statistical analysis because of the small number of patients. Patients in group 1 required a shorter ventilatory support time compared to patients in group 3 (6.5+/-7.0 versus 26.7+/-29.0 days) and group 2 (p < 0.02). In group 2 (ventilator time 30.8+/-33.7 days) early extubation was only possible in patients being operated on for chest wall instability during weaning from the ventilator. One patient in group 1, three patients in group 2 and five patients in group 3 developed pneumonia with further disturbance of gas exchange. All patients in group 1 survived; deaths in group 2 were attributed to massive hemorrhage in two and septic multiorgan failure in one patient. Four patients in group 3 died of head injury, one of acute respiratory distress syndrome, one of severe hemorrhage, and one of multiple organ failure.

CONCLUSIONS

In patients with flail chest and respiratory insufficiency without pulmonary contusion, operative chest wall stabilization permits early extubation. Patients with pulmonary contusion do not benefit from chest wall stabilization. Secondary operative chest wall stabilization in these patients is indicated when progressive collapse of the chest wall is evident during weaning from the ventilator.

The use of chest computed tomography versus chest X-ray in patients with major blunt trauma

INTRODUCTION

Computed tomography (CT) scans are often used in the evaluation of patients with blunt trauma. This study identifies the clinical features associated with further diagnostic information obtained on a CT chest scan compared with a standard chest X-ray in patients sustaining blunt trauma to the chest.

METHODS

A 2-year retrospective survey of 141 patients who attended a Level 1 trauma centre for blunt trauma and had a chest CT scan and a chest X-ray as part of an initial assessment was undertaken. Data extracted from the medical record included vital signs, laboratory findings, interventions and the type and severity of injury.

RESULTS

The CT chest scan is significantly more likely to provide further diagnostic information for the management of blunt trauma compared to a chest X-ray in patients with chest wall tenderness (OR=6.73, 95% CI=2.56, 17.70, p<0.001), reduced air-entry (OR=4.48, 95% CI=1.33, 15.02, p=0.015) and/or abnormal respiratory effort (OR=4.05, 95% CI=1.28, 12.66, p=0.017). CT scan was significantly more effective than routine chest X-ray in detecting lung contusions, pneumothoraces, mediastinal haematomas, as well as fractured ribs, scapulas, sternums and vertebrae.

CONCLUSION

In alert patients without evidence of chest wall tenderness, reduced air-entry or abnormal respiratory effort, selective use of CT chest scanning as a screening tool could be adopted. This is supported by the fact that most chest injuries can be treated with simple observation. Intubated patients, in most instances, should receive a routine CT chest scan in their first assessment.

Head-injured patients who talk and deteriorate into coma. Analysis of 211 cases studied with computerized tomography

Of 838 patients with severe head injuries admitted since the introduction of computerized tomography, 211 (25.1%) talked at some time between trauma and subsequent deterioration into coma. Of these 211 patients, 89 (42.2%) had brain contusion/hematoma, 46 (21.8%) an epidural hematoma, 35 (16.6%) a subdural hematoma, and 41 (19.4%) did not show focal mass lesions. Thus, four of every five patients who deteriorated into coma after suffering an apparently nonsevere head injury had a mass lesion potentially requiring surgery: the mass was intracerebral in 52.3% of the cases and extracerebral in 47.6%. Patients aged 20 years or less had a 39% chance of having a nonfocal mass lesion (diffuse brain damage), a 29% chance of having an epidural hematoma, and a 32% chance of having an intradural mass lesion; patients over 40 years had only a 3% chance of having a nonfocal mass lesion, an 18% chance of having an epidural hematoma, and a 79% chance of having a intradural mass lesion. Sixty-eight (32.2%) patients died and 143 (67.8%) survived. The following were independent outcome predictors (in order of significance): Glasgow Coma Scale score following deterioration into coma, the highest intracranial pressure during the patient's course, the degree of midline shift, the type of intracranial lesion, and the age of the patient. In contrast, the mechanism of injury, the verbal Glasgow Coma Scale score during the lucid interval, and the length of time until deterioration or until operative intervention did not influence the final result.

Cranial computed tomography in diagnosis and management of acute head trauma

Review of the computed tomographic findings in 286 patients with acute craniocerebral trauma revealed several types of lesions: hemorrhagic contusion, intracerebral and extracerebral hematomas, general and focal cerebral swelling, and shearing injury of the cerebral white matter. Hemorrhagic contusions are the most frequent lesion and may result in focal neurologic deficits. General cerebral swelling occurs frequently in children and necessitates prompt medical management for complete recovery. Mortality rates for intracerebral, subdural, and epidural hematomas were lower for this series than for series that preceded computed tomography. Because of the availability of computed tomography, there was an 84% reduction in arteriography, 58% reduction in surgical intervention, and a 24% reduction in skull radiography.

Computerized tomographic staging of renal trauma: 85 consecutive cases

In 85 patients with renal trauma we compared the findings on computerized tomography with those of excretory urography, renal surgery, intra-abdominal surgery and angiography. Patients underwent computerized tomography because of a suspected associated thoracic or abdominal injury, or indeterminate findings on excretory urography, nephrotomography or angiography. Blunt trauma accounted for 87.1 per cent of the renal injuries and penetrating trauma for 12.9 per cent. The most common findings on computerized tomography were perirenal hematoma in 29.4 per cent, intrarenal hematoma in 24.7 per cent and parenchymal disruption in 17.6 per cent. In 33 patients who underwent laparotomy computerized tomographic staging was confirmed. In contrast, the most common finding on excretory urography, diminished opacification (17 of 53 patients), was found to have no correlation with the severity of renal injury as assessed by computerized tomography or laparotomy. Angiography appreciably understaged 1 of 5 cases by failing to show extracapsular extravasation with parenchymal disruption. All findings on angiography were depicted by computerized tomography. We conclude that computerized tomographic staging for renal trauma is more sensitive and specific than excretory urography, nephrotomography and angiography, and that it should be used primarily when multiple traumatic injuries are suspected, when excretory urography suggests major trauma or is nonspecific and when clinical evidence of major trauma exists, regardless of what excretory urography shows.

Pulmonary contusions: quantifying the lesions on chest X-ray films and the factors affecting prognosis

OBJECTIVES

To quantify pulmonary contusions on chest x-ray film and to evaluate factors correlating with the size of the pulmonary contusions, changes in the first 24 hours, the need for ventilatory assistance, and death.

METHODS

The medical records and chest x-ray films of 103 patients with blunt chest trauma diagnosed as having a pulmonary contusion were reviewed.

RESULTS

A pulmonary contusion score was developed (3 = one third of a lung; 9 = an entire lung). In the emergency department, pulmonary contusions were not present in 11, were mild (one ninth to two ninths of a lung) in 15 patients, moderate-severe (three ninths to nine ninths of a lung) in 53 patients, and very severe in 24 patients. Within 24 hours, the pulmonary contusion score increased in 26 patients by 7.9 +/- 5.5 (SD). The 26 patients with an increasing contusion had a higher mortality rate (38% vs. 17%) (p = 0.044) and tended to need ventilatory assistance more frequently (73% vs. 49%) (p = 0.061). The 35 patients with very severe pulmonary contusions (pulmonary contusion score = 10-18) had the lowest PaO2:FIO2 ratio at 24 hours (175 +/- 103 mm Hg), longest hospital length of stay (28 +/- 35 days), and the highest Injury Severity Score (26 +/- 9). The factors correlating highest with a need for ventilatory support (57/103) were the 24 hour or initial PaO2/FIO2 ratio < 300, an Injury Severity Score > or = 24, Revised Trauma Score < 6.4, Glasgow Coma Scale score < or = 12, and shock or need for blood in the first 24 hours (p < 0.001). Death correlated highly with a need for ventilatory assistance, Injury Severity Score > or = 26, Revised Trauma Score < or = 6.3, and Glasgow Coma Scale score < or = 11 (p < 0.001).

CONCLUSION

Quantifying and noting changes in the extent of the pulmonary contusions and PaO2/FIO2 ratio during the first 24 hours may be of value in determining the need for ventilatory assistance and predicting outcome.

Pulmonary contusion. Evaluation and classification by computed tomography

In thoracic trauma, as in all of medicine, diagnosis precedes therapy. Over the past 5 years, we have liberally used chest CT examinations to improve diagnosis in the severely injured patient. This approach has significantly increased our diagnostic yield and permitted early diagnosis and treatment of unsuspected injuries. Confidence in our method of quantitation has helped us to assess the severity of pulmonary parenchymal injuries. Correlation of the CT findings with histologic study has changed our concept of pulmonary contusion from that of interstitial disease to that of pulmonary laceration with blood pneumonia.

Computed tomography in head trauma

Retrospective analysis of 200 cases of documented head trauma demonstrated an accuracy approaching 100% in the diagnosis of intra- and extracerebral collections of blood. Caution must be exercised in the evaluation of trauma 1 to 5 weeks old, since subdural hematomas have the same density as normal brain tissue, and angiography may be necessary. The clinical diagnosis of brainstem contusion is associated with a remarkably high level (54%) of surgically correctable lesions. The use of computed tomography in the evaluation of other traumatic intracranial lesions is discussed.

Computerized tomography (CT) in acute head trauma

The retrospective evaluation of 100 cases of head trauma that were subjected to computerized tomography (CT) leads to the following conclusions: (1) Computerized tomography and plain skull survey, should be the first neuroradiological procedures to perform. (2) Angiography may be carried out after computerized tomography when necessary, but as proved by this series, it will be needed in a relatively small number of cases. These include patients with technically limited CT scans or those in whom the possibility of an associated vascular lesion of the cervical or intracranial vessel is clinically suspected. (3) It is essential to obtain CT scans of the best possible quality. Sedation will be required in many instances, but this is considered worth doing because a normal CT scan, without significant technical limitations, will exclude the presence of lesions requiring prompt surgical intervention. Those patients who require surgery will need general anesthesia under any circumstances. (4) There is generally a direct relationship between the severity of clinical presentation and the CT demonstration of the abnormality responsible for the clinical status. Seventy percent of the patients clinically diagnosed as contusion had positive CT scans, and for all practical purposes, 100 percent of patients having trauma more severe than our Group III (contusion) had abnormal CT scans. Likewise, the number and intensity of tissue abnormalities on CT scans increase proportionately with the severity of the clinical signs and symptons. (5) It is foreseen that, with the advent of faster computerized tomographic scanners, the usefulness of this method will increase further, owing to a reduction in the total examination time and the lessened requirement for sedation.

Chest injuries in children: an analysis of 100 cases of blunt chest trauma from motor vehicle accidents

One hundred twenty-eight cases of chest injury were seen in a Paediatric Trauma Unit over a 5 1/2-year period. One hundred patients sustained motor vehicle accident (MVA)-related blunt chest injuries, 91 of them as pedestrians. Nine children had blunt chest injuries from falls, 10 had stab wounds (3 assault, 7 accidental), and 9 had gunshot injuries (6 from birdshot used by police during civil disturbance). MVA-related injuries were studied separately, as an etiologically homogeneous group. Sixty-five of these patients were under the age of 6. All but 3 also had serious extrathoracic injuries. The mean injury severity score (ISS) in MVA-related injuries was 25. Eight patients died, all with an ISS of 34 or more, 7 of whom had fatal head injuries. In MVA-related injuries, pulmonary contusion (n = 73) was the most frequent lesion seen, followed by rib fracture (n = 62), posttraumatic effusion (n = 58), pneumothorax (n = 38), and pneumatocele (n = 5). In MVA-related injuries, 18 children required ventilation. Thirty-nine (69%) of 56 children with radiologically evident posttraumatic pleural effusion had intercostal chest drainage. Analysis suggests that lung injury is a central event in MVA-related blunt chest trauma. Primary lung injury, radiologically visible as contusion, is complicated by hematoma, posttraumatic effusion, and pneumothorax.

Imaging of muscle injury in the elite athlete

Injuries to muscle in the elite athlete are common and may be responsible for prolonged periods of loss of competitive activity. The implications for the athlete and his/her coach and team may be catastrophic if the injury occurs at a critical time in the athlete's diary. Imaging now plays a crucial role in diagnosis, prognostication and management of athletes with muscle injuries. This article discusses the methods available to clinicians and radiologists that are used to assess skeletal muscle injury. The spectrum of muscle injuries sustained in the elite athlete population is both discussed and illustrated.

Diagnostic accuracy of bedside ultrasonography in the ICU: feasibility of detecting pulmonary effusion and lung contusion in patients on respiratory support after severe blunt thoracic trauma

BACKGROUND

Blunt thoracic trauma is a major concern in critically ill patients. Repeated lung diagnostic evaluations are needed in order to follow up the clinical situation and the results of the therapeutic strategies. The aim of this prospective clinical study was to evaluate the possible role of lung ultrasound (LU) compared with bedside radiography (CXR) and computed tomography (CT) used as the gold standard in the evaluation of trauma patients admitted to the intensive care unit with acute respiratory failure.

METHOD

A total of 15 thoracic trauma patients were studied at intensive care unit (ICU) arrival (T1) and 48 h later (T2) with CT, CXR and LU. We evaluated the presence of pleural effusion (PE) and lung contusion (LC). For this purpose the lung parenchyma was divided into 12 regions so that we could compare 180 lung regions at T1 and T2, respectively.

RESULTS

Sensitivity of ultrasound was 0.94 for PE and 0.86 for LC while specificity 0.99 and 0.97, respectively. The likelihood ratio was 94 (rho(+)) and 0.06 (rho(-)) for PE and 28.6 (rho(+)) and 0.14 (rho(-)) for LC.

CONCLUSIONS

Ultrasound provides a reliable noninvasive, bedside method for the assessment of chest trauma patients with acute respiratory failure in the ICU.

A comparison of bone scintigraphy and MRI in the early diagnosis of the occult scaphoid waist fracture

OBJECTIVE

To determine the accuracy of MRI in the assessment of the radiographically occult scaphoid fracture.

DESIGN

This prospective study compared the sensitivity and specificity of MRI for detection of radiographically occult scaphoid fractures with bone scintigraphy (BS), the currently accepted imaging modality of choice. Consecutive patients with clinical signs of a scaphoid injury but no evidence of fracture on plain radiographs at presentation and after 7-10 days were evaluated by MRI and BS. All images were reported in masked fashion and the sensitivities and specificities of the imaging modalities determined. All patients with a scaphoid fracture demonstrated by MRI or BS were followed for at least a year after injury.

PATIENTS

Forty-three subjects (aged 12-74 years) had both MRI and BS carried out on average 19 days from the injury date.

RESULTS AND CONCLUSIONS

Six patients (14%) had scaphoid waist fractures. There were other bony injuries in a further six. In 40 patients there was agreement between the BS and MRI findings. In three cases there was discrepancy between the imaging modalities; in all three MRI was found to be the more sensitive and specific. MRI could become the investigation of choice for this injury.

Blunt bowel and mesenteric injury: diagnostic performance of CT signs

PURPOSE

Our goal was to determine the sensitivity and specificity of various CT signs of blunt bowel and mesenteric injury.

METHOD

The CT findings of 31 patients with blunt abdominal trauma were retrospectively assessed by three observers in consensus. All patients had laparotomy within 24 h of CT. The study group consisted of 19 patients with surgically proven bowel and/or mesenteric injury. The control group consisted of 12 traumatized patients who had no bowel or mesenteric injury. The CT signs assessed were presence, location, and extent of intraperitoneal fluid, extraluminal air, bowel wall thickening, bowel wall discontinuity, mesenteric streaking, and mesenteric hematoma.

RESULTS

In the 12 cases of bowel injury (9 transmural injury, 3 partial thickness injury), the CT sign of bowel wall thickening had sensitivity of 50% and specificity of 84% and the CT sign of bowel wall discontinuity had sensitivity of 58% and specificity of 95%. Extraluminal air was a specific but relatively insensitive sign of transmural bowel injury (sensitivity 44%, specificity 100%). In the 13 patients with mesenteric injuries, the CT sign of mesenteric hematoma had sensitivity of 54% and specificity of 94%. Isolated mesenteric streaking was a less specific sign of mesenteric injury (sensitivity 77%, specificity 44%). The finding of peritoneal fluid with no visible solid organ injury was a useful sign of bowel or mesenteric injury, occurring in 11 of 19 (58%) study patients and none of the controls (p < 0.001).

CONCLUSION

Bowel wall thickening, bowel wall discontinuity, extraluminal air, and mesenteric hematoma are reasonably specific CT signs of bowel and mesenteric injury following blunt abdominal trauma. The presence of a moderate to large volume of intraperitoneal fluid without visible solid organ injury is an important sign of bowel or mesenteric injury.

Renal trauma: re-evaluation of the indications for radiographic assessment

We studied prospectively 359 consecutive patients with blunt (306) or penetrating (53) renal trauma to refine the indications for radiographic evaluation. Various factors, including the degree of hematuria, presence of shock and associated injuries easily assessable at the time of initial evaluation, were correlated with the severity of renal injury to determine whether any combination of parameters will separate patients with renal contusions from those with significant renal injuries (minor and major lacerations, and vascular injuries). We identified 3 groups: group 1-85 patients with gross hematuria or microscopic hematuria and shock after blunt trauma (including all 23 with significant renal injuries), group 2-221 patients with microscopic hematuria but no shock after blunt trauma (all with renal contusions) and group 3-53 patients with penetrating trauma. No combination of parameters was able to predict a severe injury in group 3. Our data support radiographic evaluation in groups 1 and 3. However, because all patients in group 2 had renal contusions and experienced no complications from nonoperative management we believe that excretory urography, which is time-consuming and costly, can be avoided in patients with microscopic hematuria but no shock after blunt renal trauma.

Alveolar recruitment in combination with sufficient positive end-expiratory pressure increases oxygenation and lung aeration in patients with severe chest trauma

OBJECTIVE

Investigation of oxygenation and lung aeration during mechanical ventilation according to the open lung concept in patients with acute lung injury or acute respiratory distress syndrome.

DESIGN

Retrospective analysis.

SETTING

Surgical intensive care unit of a university hospital.

PATIENTS

We retrospectively identified 17 patients with acute lung injury/acute respiratory distress syndrome due to pulmonary contusion who had thoracic helical computed tomography scans before and after ventilation with the open lung concept.

INTERVENTIONS

Baseline ventilation consisted of low tidal volumes (< or =6 mL/kg) and positive end-expiratory pressure (PEEP; 5-17 cm H2O). We briefly applied high inspiratory pressures for opening up collapsed alveoli. External PEEP and intrinsic PEEP were combined to keep recruited lung units open. We generated intrinsic PEEP by pressure-cycled high-frequency inverse ratio ventilation (80 min, inspiratory/expiratory ratio 2:1) and maintained our ventilatory strategy for 24 hrs. Then, after reducing total PEEP by decreasing respiratory rate, Pao2/Fio2 ratio was reevaluated. If it remained >300 mm Hg, weaning was started. If not, previous ventilator settings were resumed for another 24 hrs after recruiting the lungs once again.

MEASUREMENTS AND MAIN RESULTS

Physiologic variables and ventilator settings were obtained from routine charts. Data from computed tomography before and after the open lung concept were analyzed for volumetric quantification of lung aeration and collapse. All results are presented as median and range. During baseline ventilation, PEEP was 10 (range, 5-17) cm H2O and after recruitment 21 (range, 18-26) cm H2O. Opening pressures were 65 (range, 50-80) cm H2O. After recruitment, Pao2/Fio2 ratio was higher in all patients. Total lung volume increased from 2915 (range, 1952-4941) to 4247 (range, 2285-6355) mL and normally aerated volume from 1742 (range, 774-2941) to 2971 (range, 1270-5232) mL. Atelectasis decreased significantly from 604 (range, 147-1538) to 106 (range, 0-736) mL. Hyperinflation increased significantly from 5 (range, 0-188) to 62 (range, 1-424) mL, whereas poor aeration did not change substantially from 649 (range, 302-1292) to 757 (range, 350-1613) mL. No hemodynamic problems occurred.

CONCLUSIONS

Lung recruitment increased arterial oxygenation, normally aerated lung volume, and total lung volume while decreasing the amount of collapsed tissue. These results indicate that the open lung concept is a reasonable mode of ventilation for patients with severe chest trauma.

The usefulness of transesophageal echocardiography in diagnosing cardiac contusions

OBJECTIVES

To assess the usefulness of transesophageal echocardiography in diagnosing cardiac contusions in patients with blunt trauma.

BACKGROUND

For more than a decade, noninvasive tests, including ECGs, cardiac enzymes, nuclear studies, and transthoracic echocardiography have been utilized in an attempt to identify trauma patients with cardiac injuries. These tests have been imperfect in identifying the patients at high risk for mortality.

METHODS

We retrospectively reviewed the charts in 22 patients with transesophageal echocardiographically diagnosed cardiac contusions noting age, race, sex, transthoracic echocardiographic examinations, study quality, and outcome. We also noted the Injury Severity Score, which is a measure of the severity of illness in trauma patients. Higher scores correlate more severe injury and higher mortality. We defined cardiac contusions as presence of wall motion abnormality, including either or both ventricles, in the absence of transmural myocardial infarction on ECG following nonpenetrating chest trauma.

RESULTS

Over a 30-month period, 81 transesophageal echocardiographic examinations were performed on trauma patients. Among this group, 22 patients were diagnosed as having cardiac contusions. There were 15 patients with right ventricular contusions, 7 patients with left ventricular contusions, and 2 patients with both ventricles involved. We compared this group with all ICU trauma patients admitted to the hospital during this time period. Overall, the contusion patients had an average Injury Severity Score of 27 and a mortality of 27% compared with the overall trauma group with an Injury Severity Score of 33 and a corresponding mortality of 9% (p < 0.001). Corresponding ECGs were nondiagnostic in 73% of patients with cardiac contusion. There were no complications related to the transesophageal examinations.

CONCLUSIONS

Transesophageal echocardiographically diagnosed cardiac contusion in trauma patients carries a high mortality rate. Transesophageal examinations are safe and provide excellent quality images where transthoracic examinations were inadequate. Right ventricular contusions are approximately twice as common as left ventricular contusions.

Systemic gas embolism complicating pulmonary contusion. Diagnosis and management using transesophageal echocardiography

Systemic air embolism has been frequently reported after penetrating thoracic trauma. In blunt thoracic trauma, systemic air embolism has been rarely diagnosed, and then only after an invasive procedure such as thoracotomy. Transesophageal echocardiography has been recently introduced for the early assessment of trauma patients and is considered a sensitive noninvasive procedure to diagnose air embolism. We report three cases of systemic air embolism in patients with pulmonary contusion secondary to a blunt thoracic trauma requiring controlled ventilation. Transesophageal echocardiography was performed for evaluation of hemodynamic instability, and it showed air bubbles in the left atrium and left ventricle during the insufflation phase, which disappeared during apnea. A decrease in airway pressure (release of PEEP, low tidal volume, high frequency jet ventilation) significantly reduced the systemic air embolism. We concluded that systemic air embolism can occur after blunt thoracic trauma, and transesophageal echocardiography enables a rapid and accurate diagnosis that may be useful for therapeutic management.