Thoracic and Cardiac Trauma



Thoracic and Cardiac Trauma


Scott B. Johnson

John G. Myers



Introduction

Thoracic trauma is responsible for 20% to 25% of the estimated 150,000 trauma related deaths per year in the United States and is the leading cause of death in the first four decades of life. Two thirds of thoracic-related deaths occur in the prehospital setting, usually due to significant cardiac, great vessel, or tracheobronchial injuries. In a study of over 1,300 patients presenting to a level I trauma center with thoracic trauma, Kulshrestha and colleagues reported an overall mortality rate of 9.4%, with 56% of these occurring within the initial 24 hours. While the two strongest determinants of increased mortality were a low GCS and increased age, penetrating injury, liver or spleen injury, long bone fracture, and more than five rib fractures also adversely affected mortality [1]. In a study of trauma-related hospital deaths at an urban level I trauma center, Demetriades and colleagues found a penetrating mechanism, age more than 60, and chest AIS > 3 to be significant variables associated with patients who had no vital signs on admission [2].

Overall, motor vehicle collisions account for 70% to 80% of all thoracic injuries. The incidence of penetrating injuries varies widely but is usually more prevalent in urban centers. The majority of thoracic injuries can be treated with careful observation or tube thoracostomy. It is historically reported that 12% to 15% of patients with thoracic injury will require thoracotomy. In a Western Trauma Association multicenter review, only 1% of all trauma patients required nonresuscitative thoracotomy [3]. With the improvements in prehospital care and transport, more of the severely injured patients who would have previously died at the scene are making it to the hospital alive. Success in the management of these injuries rests in having a high index of suspicion for the life-threatening thoracic injuries, prompt recognition and treatment of associated injuries, and aggressive management of coexisting pulmonary dysfunction.


Indications for Urgent Surgical Intervention


Bleeding

Hemothorax is second only to rib fractures as the most common associated finding in thoracic trauma, being present in approximately 25% of patients with thoracic trauma. Bleeding can arise from the chest wall, lung parenchyma, major thoracic vessels, heart, or diaphragm. A small or moderate-size hemothorax that stops bleeding immediately after placement of a tube thoracostomy can usually be managed conservatively. However, if the patient continues to bleed at a rate of more than 200 cc per hour, exploration is indicated. The accumulation of more than 1,500 cc of blood within a pleural space is considered a massive hemothorax and is an indication for exploration. If the patient becomes hemodynamically unstable at anytime and an intrathoracic source is suspected, emergent thoracotomy should be performed irrespective of chest tube drainage. A chest radiograph should always be obtained after placing a tube thoracostomy to ensure proper position of the tube and complete drainage of the pleural space. Video-assisted thoracoscopic surgery (VATS) can be considered in the stable patient with retained hemothorax or in a stable patient who continues to bleed at a slow but steady rate; however, the surgeon should not hesitate to convert to open thoracotomy if visualization is inadequate or drainage and evacuation of the pleural space is incomplete.


Cardiovascular Collapse

The indications for resuscitative emergency department thoracotomy (EDT) continue to be debated. Our indications, which are considered to be fairly liberal, include (1) loss of vitals
in the Emergency Department for both blunt and penetrating trauma and (2) loss of vitals en route, with less than 10 minutes of prehospital CPR, with some sign of life upon arrival, or a suspected intrathoracic etiology. Penetrating thoracic injuries, specifically stab wounds, have the highest rate of survival. Data for blunt trauma are much less encouraging but should not be used as a deterrent, as there are several functional survivors in most reported series. A retrospective study of 959 patients undergoing resuscitative thoracotomy concluded that EDT in blunt trauma with more than 5 minutes or penetrating trauma with more than 15 minutes of prehospital CPR is futile care [4]. When performed, resuscitative thoracotomy should be performed early. Discovered tamponade should be released; massive pulmonary bleeding should be quickly controlled with staplers, clamping, or manual compression; and cardiac wounds should be controlled. With no intrathoracic source, the aorta should be clamped and internal cardiac massage continued.


Massive Air Leak

Findings on initial presentation of significant subcutaneous emphysema, a subsequent large or persistent air leak, or persistent pneumothorax should alert the clinician to the presence of a major tracheobronchial injury. This injury is potentially lethal but relatively rare, found in only 2% to 5% of patients with thoracic trauma. Significant tracheobronchial injuries may result in a massive air leak, leading to hypoventilation. Maneuvers to stabilize the patient should include decreasing airway pressures. Contralateral mainstem intubation can also be attempted. Major tracheobronchial injuries generally should be repaired as early as the patient’s condition allows.


Tamponade

Cardiac tamponade results when fluid or air collects within an intact pericardial sac, resulting in compression of the right heart with subsequent obstruction of venous return and cardiovascular collapse. Potential findings upon presentation include tachycardia and hypotension, cervical cyanosis, jugular venous distension, muffled heart sounds, and pulsus paradoxus. The diagnosis is confirmed with echocardiography, pericardial window, or at the time of emergent thoracotomy. Treatment requires prompt resuscitation and decompression of the pericardium, followed by repair of the bleeding source.


Diagnostics

Diagnostic imaging plays a key role in the management of patients after chest trauma and has considerable impact on therapeutic decision-making. The information generated by diagnostic imaging procedures not only serves to tailor therapy to the individual needs of the patient, but also helps to determine overall prognosis and outcome. Radiologic imaging plays an important role in the workup of any patient with suspected chest trauma. The chest radiograph is the initial imaging study of choice to be obtained in patients with suspected chest injury. Chest Computed Tomography (CT), however, is being used with increasing frequency in the evaluation of patients with chest trauma. CT can be useful in assessing suspected traumatic aortic, pulmonary, airway, skeletal, and diaphragmatic injuries. Magnetic resonance imaging (MRI) on the other hand has a limited role in the initial evaluation of any patient with suspected chest trauma. To undergo an MRI, the patient must be stable, and many trauma patients cannot be scanned because of bulky, mechanical supportive equipment. However, in selected patients who are hemodynamically stable, MRI may be particularly useful for the evaluation of spine and diaphragm injuries. Other imaging modalities available to the clinician include echocardiography, angiography, and VATS, which can be both diagnostic and therapeutic when appropriately indicated.


Plain Chest Radiograph

The frontal chest radiograph is the most appropriate initial radiographic study to obtain for the evaluation of patients with suspected chest injury. This study is particularly useful in helping to rule out major injury. Ideally, the radiograph should be obtained with the patient in the upright position because of mediastinal widening that is typically seen in the supine position. Chest radiography has a 98% negative predictive value and is therefore quite useful when normal. However, abnormal findings may be subtle and quite nonspecific. Radiographic findings that may indicate mediastinal injury, such as major aortic disruption, include abnormal contour or indistinctness of the aortic knob, apical pleural cap, rightward deviation of the nasogastric tube, thickening of the right paratracheal stripe, downward displacement of the left mainstem bronchus, rightward deviation of the trachea, and, not uncommonly, nonspecific mediastinal widening. Most life-threatening injuries can be screened by the plain chest radiograph and a careful physical exam. Blunt thoracic injuries detected by CT alone infrequently require immediate therapy. If immediate therapy is needed, findings will usually be visible on plain radiographs or obvious on clinical exam. Although a plain upright chest radiograph remains one of the basic imaging studies routinely performed on initial screening, it may be over-utilized. A recent study suggests that in the presence of a normal physical exam in the hemodynamically stable patient, obtaining a routine chest radiograph is actually unnecessary, since it rarely, if ever, changes clinical care [5].


Chest Computed Tomography

CT is highly sensitive in detecting thoracic injuries after blunt chest trauma and is superior to routine CXR in visualizing lung contusions, pneumothorax, and hemothorax, and it can often alter initial therapeutic management in a significant number of patients with suspected chest trauma. It has also been shown to detect unexpected injuries and abnormalities, resulting in altered management in a substantial number of patients when applied appropriately [6]. It can be particularly useful in screening for major intrathoracic aortic injury. In one study, contrast-enhanced CT scanning was 100% sensitive in detecting major thoracic aortic injury based on clinical follow-up and was 99.7% specific, with 89% positive and 100% negative predictive values for an overall diagnostic accuracy of 99.7% [7]. An unequivocally normal mediastinum at CT, with no hematoma and a regular aorta surrounded by a normal fat pad, has essentially a 100% negative predictive value for aortic injury [7,8,9,10]. It has also been shown that CT scanning detects 11% of thoracic aortic injuries that are not detected by routine, plain chest radiography alone [11].

CT scanning can also be useful in detecting hemopericardium and/or hemothorax from any cause, injury to the brachiocephalic vessels, pneumothorax, rib fractures, pulmonary parenchymal contusion, and sternal fractures. It can also be useful in detecting pneumomediastinum caused by pulmonary interstitial emphysema, bronchial or tracheal rupture (commonly associated with pneumothorax), esophageal rupture, or iatrogenic injury from over-ventilation or traumatic intubation. In addition, CT scanning can detect injuries otherwise missed by routine plain radiograph. In one study comparing CT
scanning with plain radiography, CT scanning detected serious injuries in 65% of those patients not found to have injury on plain film. These injuries included (in decreasing order of frequency) lung contusions, pneumothoraces, hemothoraces, diaphragmatic ruptures, and myocardial ruptures [12]. Even in those patients without suspected chest trauma, CT scanning of the abdomen, which commonly includes the lower portion of the thorax, often yields important information regarding possible intrathoracic injury. In one study, hematoma surrounding the intrathoracic aorta near the level of the diaphragmatic crura seen on intra-abdominal CT scanning was found to be a relatively insensitive but highly specific sign for thoracic aortic injury after blunt trauma. Therefore, the presence of this sign seen on abdominal CT imaging should prompt more specific imaging of the thoracic aorta to evaluate potential thoracic aortic injury [13]. CT scanning has also been shown to be useful to help define the extent of pulmonary contusion and identify those patients at high risk for acute pulmonary failure in those patients with PaO2/FIO2 lower than 300. 3-D CT scanning has also been shown to be useful in diagnosing and determining the severity of sternal fractures [14]. With the advent of high resolution CT scanners that can reconstruct axial, coronal, and sagittal images, even penetrating diaphragmatic injuries, which are difficult to image preoperatively, can be diagnosed with a relatively high sensitivity and specificity [15]. Despite its usefulness however, thoracic CT scanning is not necessarily routinely indicated for all patients with chest wall trauma. In addition, although there has been a dramatic increase in the utilization of CT scanning in the last decade, its usefulness in detecting clinically relevant injury has recently come into question, especially in those patients with a normal screening plain chest radiograph [16].


Ultrasound

Transesophageal echocardiography (TEE) is rapidly gaining acceptance as an important diagnostic tool available to the trauma surgeon and is showing particular promise in diagnosing traumatic intrathoracic aortic injuries. Although somewhat invasive, its portability makes it a diagnostic procedure of choice in looking at the heart and great vessels in multiply injured trauma patients. In one particular study of 58 patients with thoracic trauma, TEE demonstrated its usefulness in diagnosing thoracic aortic injury and permitted the identification of small lesions not detectable by CT scanning or angiography [17]. TEE has shown to be an important diagnostic tool for examining the thoracic aorta and is valuable in identifying aortic injury in high-risk trauma patients who are too unstable to undergo transport to the aortography suite. Nienaber et al. prospectively compared TEE with aortogram in evaluation of nontraumatic aortic dissection and found the technique to be a safe and highly sensitive method of diagnosing lesions of the descending aorta, with accuracy approaching 100% [18]. When an aortic injury is present, typical findings on the TEE can include aortic wall hematomas, intimal flaps, or disruptions. Several groups have shown TEE to be accurate in identifying aortic pathology after trauma, with its diagnostic efficacy mainly limited by the experience of the person performing the exam [19,20,21]. In addition, it has been shown to be useful in diagnosing blunt cardiac rupture, when other diagnostic modalities have failed, as well as in diagnosing severe valvular regurgitation intraoperatively following foreign body removal [22,23].

Numerous studies report that transthoracic echocardiography (TTE) is emerging as an effective noninvasive screening examination for pericardial effusion in the trauma setting. Although subxiphoid pericardial window is currently considered the gold standard to confirm the diagnosis of pericardial tamponade, conventional 2-dimensional TTE has been shown to reveal as little as 50 mL of blood within the pericardium and can show cardiac pseudoaneurysms and the location of foreign bodies [24,25,26,27]. Lopez et al. [28] showed that TTE can detect and distinguish hemopericardium from other effusions of lower echogenicity. In prospective studies of patients sustaining penetrating precordial injuries, TTE demonstrated sensitivities of 56% to 90%, with specificities of 93% to 97%. Its overall accuracy was 90% to 96% [29,30]. Because TTE is an examination that can be performed at the bedside, it can be performed rapidly and may decrease the time to diagnosis versus pericardial window (15.5 minutes vs. 42.4 minutes in one study by Meyer et. al.) [30]. It has also been shown that earlier therapeutic intervention facilitated by TTE may be associated with improved survival [31]. In addition, TTE has been shown to be able to identify cardiac sources for hemodynamic instability in the operating room unrelated to tamponade, such as the relatively rare case of atrioventricular valve rupture, which would otherwise be difficult to diagnose, therefore allowing for expeditious repair using cardiopulmonary support [32]. Thus, both TTE and TEE are emerging as useful screening modalities that can be used to evaluate both penetrating and blunt cardiac injuries.


Angiography

Thoracic aortography historically has been the gold standard for diagnosing thoracic aortic injury and for defining the extent of the injury and involvement of branch disease, if present. Aortography usually requires approximately 40 mL of a nonionic iodinated contrast material injected at a rate of 18 to 20 mL per sec. At least two views are obtained—one in the anteroposterior plane and another usually at a 45 degree left anterior oblique projection. If these do not accurately visualize the areas of concern, then additional views may be necessary, either from a lateral or a right anterior oblique projection. Diagnosis of aortic injury angiographically is usually made by finding one or more of the following: an irregular or discontinued contour of the aortic lumen, an intimal flap, an aortic dissection, and/or a luminal outpouching (i.e., pseudoaneurysm). Thoracic aortography can detect blunt traumatic aortic injuries with 96% sensitivity and 98% specificity. False negative examinations are usually related to incomplete or inadequate injections or projections. To be an adequate study, the aortic root as well as the distal descending thoracic aorta should be visualized since these locations are involved, respectively, with 8% and 2% of all blunt thoracic aortic injuries. False positives usually relate to a prominent ductus diverticulum or from an ulcerated atheromatous plaque. A ductus diverticulum can be seen in up to 9% of thoracic aortograms and is related to a remnant of the enlarged mouth of the ductus arteriosus. It appears as a localized bulge of the anterior wall of the aorta and can be differentiated from a pseudoaneurysm due to its usually smooth, regular, symmetrical borders; intimal disruption is typically absent. In addition, the aortic lumen adjacent to the diverticulum is not narrowed, and there is absence of retention of contrast upon the wash-out phase of the angiogram, which is often typical of pseudoaneurysms. Ulcerated atheromas usually are small, isolated outpouchings of the aortic wall with a collar button appearance. They are typically located in the mid-descending aorta rather that at the aortic isthmus. It is not uncommon for them to occur in individuals that demonstrate widespread atherosclerotic disease and should, therefore, be suspected on angiograms obtained in clinically relevant individuals. Angiography is invasive and can have associated complications. The complications associated with arteriography include allergic reactions, renal failure, local puncture site problems, stroke, and even death. Radiographic contrast media cause severe anaphylactic reactions in less than 2% of cases. A prior history of allergic reaction to intravascular contrast material increases the risk for a subsequent reaction, even after premedication with histamine
blockers and steroids. Patients with preexisting comorbidities, such as renal disease, diabetes mellitus, congestive heart failure, or who are elderly (over 70 years of age) have the highest risk for acute renal dysfunction following contrast administration. The reported incidence of contrast-induced nephropathy varies from less than 1% in the general patient population to as high as 92% among patients with comorbidities that predispose to renal insults, such as diabetes and renal insufficiency [33].

Arteriography requires arterial puncture with cannulation, usually percutaneously. Possible entry sites include not only the femoral artery (most common) but also the axillary and brachial arteries. Possible puncture site complications include hematoma, pseudoaneurysm, arteriovenous fistula, hemorrhage, arterial thrombosis, and femoral neuralgia. Fortunately, clinically significant local arterial complications occur in only 0.1% to 5% of cases. The risk of complications is also related to the indication for arteriography. Fortunately, the lowest risk for complications occur in trauma patients and the complication rates quoted in older studies may not accurately reflect current risk.


Video-Assisted Thoracoscopic Surgery

The role of thoracoscopy in trauma has been explored by a number of investigators in the literature. Prior to the modern video era, Jones et al. described management of 36 patients with thoracoscopy under local anesthesia as a diagnostic tool to define intrathoracic injuries and to visualize ongoing hemorrhage [34] Four patients in their series were spared abdominal exploration when the diaphragm was found devoid of injury. More recently, Ochsner et al. [35] and Mealy et al. [36] have demonstrated the usefulness of VATS as a diagnostic tool in the assessment of diaphragmatic integrity in cases of penetrating and blunt thoracic injuries respectively. VATS has become an acceptable surgical modality in the diagnostic evaluation of suspected diaphragmatic injury and has been shown to have therapeutic benefit when evacuation of clotted hemothoraces is able to be performed in stable patients with penetrating chest injures [37]. Main indications for VATS include diagnosis and treatment of diaphragmatic injuries, diagnosis of persistent hemorrhage, management of retained thoracic collections, assessment of cardiac and mediastinal structures, diagnosis of bronchopleural fistulas, and diagnosis and treatment of persistent posttraumatic pneumothorax. VATS has been shown to be a useful alternative to an open thoracotomy in selected patients. Because lung deflation with single-lung ventilation is a critical component of the technique, VATS is relatively contraindicated in patients unable to tolerate this. Caution should be used in patients with suspected obliteration to their pleural cavity secondary to previous infection (“pleurisy”) or surgery. VATS should have no role in the management of unstable patients or in those patients unable to tolerate formal thoracotomy for any reason. Whether VATS should be considered as the initial approach in evaluation of all stable chest trauma patients when an intrathoracic injury is suspected is still debated, and appropriate patient selection remains important.


Specific Injuries


Chest Wall


Rib Fractures

Rib fractures are a common injury and are often associated with other injuries. Rib fractures themselves usually cause only minor problems; however, they may be a marker of more severe injury, and it may be the underlying pulmonary contusion that often accompanies the rib fracture that may be more clinically relevant. A study by Flagel et al. showed that 13% of those patients in the National Trauma Data Bank who had one or more rib fractures (n = 64,750) developed complications including pneumonia, acute respiratory distress syndrome, pulmonary embolus, pneumothorax, aspiration pneumonia, empyema, and the need for mechanical ventilation. They also showed that increasing number of rib fractures correlated directly with increasing pulmonary morbidity and mortality. The overall mortality rate for patients with rib fractures was 10%. The mortality rate increased (p < 0.02) with each additional rib fracture, independent of patient age. This ranged from 5.8% for a single rib fracture to 10% in the case of 5 fractured ribs. The mortality rate increased dramatically for the groups with 6, 7, and 8 or more fractured ribs to 11.4%, 15.0%, and 34.4%, respectively [38]. Interestingly, in their study epidural analgesia was associated with a reduction in mortality for all patients sustaining rib fractures, particularly those with more than four fractures. Since this was not a prospective randomized study, it is difficult to tell if there was a correlation between patients that received epidural catheters having an overall lower injury severity score. However, in one prospective randomized trial by Bulger et al., trauma patients with rib fractures were randomized to either receive epidural anesthesia or intravenous opioids for pain relief, and it was shown that those patients with epidural anesthesia had a lower incidence of nosocomial pneumonia and shorter duration of mechanical ventilation [39]. The number of patients that could receive epidural anesthesia was limited, however, due to strict inclusion criteria. The age of the patient sustaining rib fractures should be taken into account, as well as the location of the fractures. It has been shown that rib fractures occurring in the very young should alert the clinician to possible nonaccidental trauma (NAT). In one study by Barsness et al., rib fractures in children under 3 years of age had a positive predictive value of NAT of 95%, and rib fracture was the only skeletal manifestation of NAT in 29% of the children [40]. With regards to the elderly, it has been shown that there is a linear relationship between age and complications, including mortality. It has been shown that elderly patients with rib fractures have up to twice the mortality of younger patients with similar injuries [41]. In addition, this increase in mortality may begin to be seen in patients as early as 45 years of age when more than four ribs are involved [42]. The location of the rib fracture(s) is also important, as it has been shown that left-sided rib fractures are associated with splenic injuries, and right-sided rib fractures are associated with liver injuries. While isolated rib fractures have an associated incidence of vascular injury of only 3%, first rib fractures in association with multiple rib fractures have a 24% incidence of associated vascular injury. A first rib fracture along with findings of a widened mediastinum, upper extremity pulse deficit, brachial plexus injury, and/or expanding hematoma should prompt work-up for a possible subclavian arterial injury.


Flail Chest

Flail chest occurs when multiple adjacent ribs are broken in two locations, thereby allowing that portion of the chest wall to move independently with respiration. The strict definition of flail chest is the fracture of at least four consecutive ribs in two or more places; however, the functional definition is an incompetent segment of chest wall large enough to impair the patient’s respiration. Major mortality and morbidity of flail chest can be attributed to the usual underlying associated pulmonary contusion and the hypoventilation/hypoxia that results from the paradoxical movement of the chest wall. This is a mechanical problem in which negative pressure generated during inspiration within the thorax is dissipated by movement of the flail segment inward. This movement equalizes the intrathoracic
pressure, which would normally be accomplished by the movement of air into the lungs. In addition, the underlying pulmonary contusion usually leads to a ventilation perfusion mismatch, contributing to the hypoxia; the pain associated with multiple rib fractures can lead to splinting and contribute to hypoventilation. As a result, both oxygenation as well as ventilation is compromised. Usually a large number of ribs have to be involved to be clinically significant. Fortunately, this occurs relatively rarely with rib fractures. Flagel et al. showed an overall incidence of flail chest of 3.95% in patients with 6 rib fractures; 4.84% in those with 7 rib fractures; and 6.42% in those with 8 or more rib fractures [38].

The basic treatment for flail chest injury has not changed appreciably over the last several decades. Ventilatory support in the form of mechanical, positive pressure ventilation remains the gold standard against which all other forms of treatment are measured. Avery et al. coined this type of treatment “internal pneumatic stabilization” in 1956 [43]. Positive pressure ventilation, which effectively forces the flail segment to rise and fall normally with inspirations, effectively allows stabilization of the flail segment with respect to the remainder of the chest wall. Surgical stabilization of the chest wall has been shown to be of some benefit with regard to shorter length of ventilator dependency, lower rates of pneumonia, and shorter intensive care unit stays, although this form of therapy is not yet widely practiced [44]. Pain control continues to be an important adjunct in any treatment regimen.


Sternal Fracture

Sternal fractures have been shown to decrease the stability of the thorax in cadavers [45]. They usually occur as a deceleration force during traffic accidents together with blunt force trauma from foreign objects, such as steering wheels, although they have been reported as a complication of CPR, which interestingly was found in 14% of medical autopsy cases that had received chest compressions prior to death [46]. Traffic accidents are the cause of sternal fractures in almost 90% of cases, with approximately 25% of fractures graded as moderately to severely displaced. Approximately 30% of patients will have associated injuries, with craniocerebral trauma and rib fractures being the most commonly associated injuries [47]. Displaced fractures are more likely to have associated thoracic and cardiac injuries and are more likely to require surgical fixation.

However, the majority of patients can be safely observed and even discharged home as long as the following criteria are met: (1) the injury is not one of high-velocity impact, (2) the fracture is not severely displaced, (3) there are no clinically significant associated injuries, and (4) complex analgesic requirements are not required. Most serious complications and deaths that occur in patients with sternal fractures are not due to the fracture itself but rather are related to the associated injuries, such as flail chest, head injury, or pulmonary or cardiac contusion. Although approximately 22% of patients will exhibit electrocardiographic changes, elevated creatine kinase MB isoenzymes, or echocardiographic abnormalities, only approximately 6% of patients will exhibit a clinically significant myocardial contusion. In addition to myocardial contusion, other complications of sternal fracture such as mediastinal abscess, mediastinitis, and acute tamponade have all been reported. Indications for operative sternal fixation are certainly not absolute and should be judged individually. Generally accepted criteria include severe pain, sternal instability causing respiratory compromise, and severe displacement. Only a small percentage of patients (2% in one series) actually require sternal fixation [48]. A lack of consensus among surgeons on how to treat these injuries, in addition to a lack of randomized trials concerning their optimal approach, continues to prevail.


Scapular Fracture

Scapular fractures are relatively rare and were once presumed to be an indicator of severe underlying trauma and subsequent higher mortality. They occur in only approximately 1% to 4% of blunt trauma patients who present to a level I trauma center and are associated with a higher incidence of thoracic injury compared to those patients who sustain blunt trauma without a scapular fracture. However, more recent studies have indicated that although patients with scapular fractures tend to have more severe chest injuries and a higher overall injury severity score, their length of intensive care unit stay, length of hospital stay, and overall mortality is not necessarily increased [49,50]. Treatment is usually conservative and, most of the time, necessarily aimed at the associated injuries that are commonly present.


Scapulothoracic Dissociation

Scapulothoracic dissociation is an infrequent injury with a potentially devastating outcome. Scapulothoracic dissociation results from massive traction injury to the anterolateral shoulder girdle with disruption of the scapulothoracic articulation. Identification of this injury requires a degree of clinical suspicion, based upon the injury mechanism and physical findings. Assessment of the degree of trauma to the musculoskeletal, neurologic, and vascular structures should be made. Based upon clinical findings, a rational diagnostic approach can be navigated and appropriate surgical intervention planned. Scapulothoracic dissociation frequently is associated with acromioclavicular separation, a displaced clavicular fracture, subclavian or axillary vascular disruption, and a sternoclavicular disruption. Clinically, patients usually present with a laterally displaced scapula, a flail extremity, an absent brachial pulse, and massive swelling of the shoulder. Vascular injury occurs in 88% of patients and severe neurologic injuries occur in 94% of patients. Many of these patients have a poor outcome and present with a flail, flaccid extremity that usually results in early amputation and have an overall mortality of 10%. One of the most devastating aspects of scapulothoracic dissociation is the brachial plexus injuries that occur, which are typically proximal, involving the roots and cords—brachial plexus avulsions are not unusual. Attempts at repair of complete brachial plexus injuries with grafts or nerve transfers have generally been unsuccessful [51]. Treatment includes arterial and venous ligation to stop exsanguination if present, orthopedic stabilization and consideration for above elbow amputation electively, if brachial plexus avulsion is present, to allow for a more useful extremity. Overall prognosis for limb recovery is poor.

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Sep 5, 2016 | Posted by in CRITICAL CARE | Comments Off on Thoracic and Cardiac Trauma

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