General Thoracic Surgery (General Thoracic Surgery (Shields)) [2 VOLUME SET]

Editors: Shields, Thomas W.; LoCicero, Joseph; Ponn, Ronald B.; Rusch, Valerie W.

Title: General Thoracic Surgery, 6th Edition

Copyright 2005 Lippincott Williams & Wilkins

> Table of Contents > Volume I - The Lung, Pleura, Diaphragm, and Chest Wall > Section XII - Thoracic Trauma > Chapter 70 - Blunt and Penetrating Injuries of the Chest Wall, Pleura, and Lungs

Chapter 70

Blunt and Penetrating Injuries of the Chest Wall, Pleura, and Lungs

Geoffrey M. Graeber

Ganga Prabhakar

Thomas W. Shields

The most important concept in treating the patient suffering from thoracic trauma is thorough evaluation of the entire patient with appropriate prioritization of the magnitude and severity of all injuries. A vigorous, systematic approach is mandatory to treat life-threatening injuries in view of their relative danger to the life of the patient. Once the patient has been stabilized by the surgeon in charge, each of the documented injuries can be treated in accordance with their assigned priority. Probably the most uniformly accepted system for the treatment of trauma patients is that delineated by the American College of Surgeons Advanced Trauma Life Support Course (2001). This system has been adopted by most trauma centers in the United States as well as by the United States military services. In this system, the thoracic surgeon may indeed be the primary provider of care for the acute trauma patient. In this role, the thoracic surgeon not only acts as the principal care provider for the trauma patient but also performs the functions of the thoracic surgical consultant for any injuries most appropriately treated by a thoracic surgeon. More commonly, the thoracic surgeon is a consultant called by a trauma surgeon to treat specific thoracic surgical problems.

This chapter will focus on the evaluation and treatment of injuries to the chest wall, pleura, lungs, and tracheobronchial tree. Injuries to the diaphragm and esophagus are presented in Chapters 74 and Chapter 138, respectively. Although, knowing full well that vascular and cardiac injuries are of great importance, these subjects are not addressed in this text.

HISTORY

Thoracic injuries have been discussed since the earliest medical writings. Breasted (1980), in his work on the Edwin Smith surgical papyrus, noted that 8 of the 43 injuries discussed were thoracic in nature. Although the papyrus dates to 3000 BC, successful management of thoracic injuries, particularly those of the chest wall, were carried out. Meade (1961), in his volume on thoracic surgical history, noted that Homer, in his description of the siege of Troy (950 BC), had graphically described the death of Sarpedon due to a penetrating thoracic wound. The lesson from this description is important for the practicing thoracic surgeon today. Withdrawal of a weapon or impaling object from the thorax can cause exsanguinating hemorrhage because the object can be penetrating the heart or a great vessel.

Accounts of military surgeons through the ages have documented advances in thoracic surgery, but the most rapid advances in the treatment of thoracic wounds have occurred in the 20th century. Review of the accounts of Hochberg (1980) and by Kovaric and associates (1969) showed that the mortality rate from thoracic wounds dropped from 63% in the American Civil War to 9% in the Vietnam conflict.

During World War I, some patients with empyema and major chest wall injuries survived by open packing of their wounds, as noted by Seyfer and associates (1986). These same authors also noted that the first major successful management of chest injuries occurred during World War II with the application of closed chest drainage systems and improved general endotracheal anesthesia.

INCIDENCE

Traumatic injuries of all types are responsible for approximately 150,000 deaths per year in the United States. In persons younger than 40 years of age, traumatic injury is the most common cause of death. Thoracic injuries are responsible for about one fourth of the deaths, as pointed out by LoCicero and Mattox (1989). In the military trauma experience, many chest injuries are lethal before the patient reaches any sort of medical treatment facility, as pointed out by Seyfer and colleagues (1986).

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There has been signfiicant controversy during the last decade of the 20th century and the initial years of the 21st century as to the efficacy of cardiopulmonary resuscitation (CPR) of trauma patients at the site of injury who for all intents and purposes appear to be dead [i.e., absent heart rate, zero blood pressure, absent respiratory effort, and a Glasgow Coma Score (GCS) of 3 (Appendix A)]. The data relative to initial survival rates with active CPR vary from 0% to 23% in adults, as recorded in the studies of Martin (2002), Battistella (1999), Stratton (1998) and Pasquale (1996) and their associates, among other reports in the trauma literature. In children, the initial survival rate was for all purposes the same (i.e., 1.5% to 25%) in the studies of Calkins (2002), Li (1999) and Suominen (1998) and their colleagues, as well as in other reports. Unfortunately, the criteria of selection of this group of patients varies greatly as to when they had been evaluated, whether closed CPR was done before hospital admission, the duration of time before emergency medical care, and the cause of the traumatic event (i.e., penetrating trauma, blunt trauma, or other causes, such as burns, smoke inhalation, drowning, hanging, or other injuries). In the chest injury patient, with rare exception, the cause is either penetrating or blunt trauma, the latter mostly related to vehicular or pedestrian accidents. Multiple factors must be considered, but under the best of circumstances, the results of attempted resuscitation in the aforementioned dead trauma patients are poor.

In the report by Stockinger and McSwain (2004) from the Tulane University Health Sciences Center-Charity Hospital trauma group of 16,651 level I trauma patients seen in a 6-year period, on-site CPR was done in 583 patients with no signs of life. The number of eventual survivors in these 583 patients (3.5% of all level I trauma patients) that met the aforementioned criteria was 22 (3.8%). Only 0.9% of 338 patients with penetrating injuries, 6.2% of the 192 blunt trauma patients, and 13.2% of 53 patients with other traumatic causes survived (Table 70-1). The results of this experience support the recently published guidelines for withholding or termination of resuscitation in prehospital patients with traumatic cardiopulmonary arrest when first seen at the accident site published by Hopson and coinvestigators (2003). In the latter report, it was suggested that such resuscitative efforts are no longer required or even possibly indicated in adults 18 years or older who are blunt trauma victims and are apneic and pulseless at the time of the arrival on the scence of the emergency medical services physician (EMSP). The criteria for this decision are more strict after penetrating trauma. Of course, the final decision to withhold CPR in the field remains the prerogative of the medical control physician at the trauma center based on the information supplied by the EMSP. With this information as a background, one may then consider the results following vigorous resuscitative efforts in patients who continue to deteriorate during the time of transportation to the hospital and who are found to be dead on arrival at the emergency room. The report of Demetriades and associates (2004) from the University of Southern California may give some somber answers. During the period of study (January 1993 to June 2002), 34,120 trauma victims who met one or more of their trauma registry criteria (Table 70-2) were admitted. Blunt trauma accounted for 65% of the patients, and penetrating trauma accounted for 35%. The mean Injury Severity Score (ISS) (Appendix B) was not significantly different in the two groups (26.5 vs. 30.6, respectively). Overall, there were 2,648 hospital deaths (7.8%) 3.7% in patients with blunt trauma and 4% for those with penetrating trauma. The most common body areas with critical injuries with an Abbreviated Injury Scale (AIS) (Appendix C) of greater than or equal to 4 were those of the the head (43%), followed by those of the chest (28%), and those of the abdomen (19%). Overall, 2.9% (979 patients) were dead on arrival ; 61% of these victims had severe chest injuries. One hundred seventeen (12%) of the patients with no vital signs were initially successfully resuscitated. However, 77% of these resuscitated patients died within 1 to 6 hours, 17% between 6 and 24 hours, 3% between 24 and 72 hours, and 3% after 72 hours (a 100% mortality rate).

Of the 33,141 patients (97.1%) with vital signs present on admission, those patients with severe chest trauma constituted the greatest number who died shortly after admission (i.e., within the first 6 hours). Death as a result of penetrating trauma was significantly more likely to occur in the emergency room or the operating room, whereas in patients with severe blunt trauma, death occurred somewhat later, and the patient was most likely to be in the trauma intensive care unit at the time.

Despite these discouraging data, patients with severe chest injuries who respond to appropriate prehospital measures, as well as immediate adequate resuscitative measures,

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EVALUATION AND MANAGEMENT

Initial evaluation of each patient must be directed at correcting life-threatening conditions immediately and documenting the less serious injuries for later correction. The assessment and treatment prioritization schema recommended by the Advanced Trauma Life Support Course of the American College of Surgeons (2001) should be followed for all patients. The primary survey of all patients considers airway, breathing, and circulation as the most important features to be stabilized immediately. This initial evaluation emphasizes the findings in the total evaluation of each patient that portend serious consequences. All parts of the physical examination are conducted in a focused manner to identify and correct potentially lethal conditions immediately. Examination of the mouth and neck focuses on identifying any symptoms of airway obstruction while protecting against any further injury due to cervical spine manipulation. Neck veins are examined for either distention or collapse (circumoral cyanosis is noted if present). Evaluation of the respiratory mechanics of chest wall motion is carried out to detect inhibition due to rib fractures or paradoxical motion due to flail chest. Auscultation permits the evaluation of the distribution of breath sounds, their character, and any crepitus present in the chest wall. Percussion notes areas of hyperresonance as well as dullness. Palpation of the chest wall permits the identification of any areas of crepitus, hematomas, irregularities due to rib fracture, and areas of point tenderness due to fractures. The findings on physical exam are be integrated by the treating surgeon into a prioritized plan of treatment for the injuries present.

Imaging modalities are used, when possible, to confirm diagnosis suspected by findings on physical exam and to assess the efficacy of therapeutic interventions directed at alleviating specific conditions. Chest radiographics are the most frequently used modality, followed closely by computed tomography (CT). CT has become increasingly available in emergency departments throughout North America in recent years. The use of ultrasonography in the emergency department also has increased as its availability has risen. More sophisticated modalities, such as magnetic resonance (MR) imaging, may be helpful in further characterizing injuries after the patient has been stabilized and can be transported with little potential threat of exacerbating injuries. The integration of radiology suites into emergency and trauma departments has facilitated the use of more sophisticated imaging techniques in the evaluation and treatment of trauma patients.

INJURIES SUSTAINED AS THE RESULT OF THORACIC TRAUMA

Traumatic Asphyxia

Traumatic asphyxia results from a severe blunt injury of the thorax. It manifests itself with facial and upper chest petechiae, subconjunctival hemorrhages, cervical cyanosis, and occasionally neurologic symptoms. Temporary impairment or loss of vision, presumed to be due to retinal edema, rarely may be present. Factors implicated in the development of these striking physical characteristics include thoracoabdominal compression after deep inspiration against a closed glottis, which results in venous hypertension in the valveless cervicofacial venous system. Williams (1968) and Lee (1991) and their colleagues recommend that treatment is primarily supportive; concurrent injuries, however, should be excluded. The traumatic asphyxia is self-limiting, and no special treatment is required.

Mediastinal and Subcutaneous Emphysema

Injuries to the tracheobronchial tree, esophagus, and lungs can all lead to mediastinal emphysema. Rupture of the lung substance due to a penetrating injury or severe blunt trauma typically leads to a pneumothorax. Severe blunt trauma also may result in a laceration or rupture of a central airway. In such instances, Battistella and Benfield (2000), among others, have noted that air may dissect back along the bronchi and vessels into the mediastinum. If the leak is large, air migrates into the subcutaneous space of the neck, from where it can extend to the face and torso down to the inguinal ligament and occasionally to the external genitalia. Tracheobronchial injury should be suspected when a large amount of mediastinal air is present, especially if the pneumomediastinum seems to increase with mechanical ventilation. If this occurs, inspection of the tracheobronchial tree is indicated. Treatment and management should address the etiology of the mediastinal or subcutaneous

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Rib Fractures

Rib fractures have been reported by Kemmerer (1961) and Conn (1963) and their associates in 35% to 40% of thoracic trauma victims, making these fractures the most common major thoracic injury. As suggested by Battistella and Benfield (2000), the diagnosis is based primarily on clinical findings. Posttraumatic pleuritic chest pain is usually diagnostic of rib fractures; these fractures can be localized by palpation. Nonetheless, it is important to quantitate the severity of rib fractures for prognosis and to map which ribs are fractured to assist in making a judgment as to possible types of associated injuries. Chest radiographs are largely used to identify associated intrathoracic injuries. CT scans not only are useful in identifying rib fractures but also may delineate associated internal injuries as well. Gregory and colleagues (2002) have recommended the use of bone scans to detect occult fractures in athletes.

Fractures of One or Two Ribs Unilaterally

Management of one or a few rib fractures is directed at identifying any associated injuries and at controlling the chest wall pain that, if left untreated, leads to splinting of the chest with resultant hypoventilation. Decreased excursions of the chest wall and poor pulmonary hygiene may lead to atelectasis, pneumonia, and respiratory failure. Wisner (1990) has shown that the prompt use of epidural analgesia results in a lower morbidity and mortality than the use of parenteral narcotics, particularly in elderly patients. Early mobilization, deep inspiratory efforts, and frequent coughing should be encouraged. Pulmonary physiotherapy, nasotracheal suctioning, and prompt bronchoscopy should be instituted in patients unable to clear secretions. Although young patients with a single rib fracture may be managed with oral narcotics, those with multiple fractures often require parenteral narcotics. Moreover, the older patient, even with less than three fractured ribs, is best managed with patient-controlled intravenous analgesia using the narcotic of choice to obtain adequate pain relief. Alternative methods for controlling pain due to thoracic injury include intercostal nerve blocks, intrapleural catheter analgesia, or transcutaneous electric nerve stimulation. According to Battistella and Benfield (2000), each of these modalities has disadvantages. First, intercostal nerve blocks require repeated administration, and each injection exposes patients to the risk for pneumothorax. Second, intrapleural regional analgesia with a catheter in the pleural cavity achieves adequate pain control without sedation or respiratory depression; however, catheter placement carries the risk for pneumothorax and, based on the report by Luchette and colleagues (1994), appears to be less effective than epidural analgesia. Third, transcutaneous electric nerve stimulation is of no benefit immediately after trauma; this method should be limited to controlling pain in a chronic setting. Because of these aforementioned disadvantages, none of these three alternative methods of pain control are generally indicated in the acute trauma patient.

Fractures of the First and Second Ribs

Fractures of the first and second ribs indicate the possible existence of additional serious intrathoracic injury. Some investigators have suggested that routine aortography be done in patients with first or second rib fractures to rule out associated vascular injuries. Poole (1989), however, suggested that this is not needed unless other signs of injury to the thoracic aorta or great vessels are present. Nonetheless, it is noteworthy to point out, as recorded by Richardson and colleagues (1975), that fractures of the upper ribs (and including the scapula) have been associated with a mortality rate of up to 36%. According to the aforementioned authors, concomitant injuries to the head (53%), abdomen (33%), and other structures within the thorax (64%) are often found in these patients.

Multiple or Bilateral Rib Fractures

Wilson (1977) and Garcia (1990) and their co-workers have documented that the outcome of treatment (and therefore the prognosis) for rib fractures is related to the number of ribs injured, the patient's age, and the patient's underlying pulmonary status. In the experience of Worthley (1985), as well as that of Mackersie (1987) and Wisner (1990) and their colleagues, continuous administration of epidural analgesia is universally useful in patients with severe chest wall injuries such as multiple bilateral rib fractures, flail chests, or a combined thoracoabdominal injury. Conn and associates (1963) and Worthley (1985) have noted that the mortality rate from isolated rib fractures in the elderly has been as high as 10% to 20%. Rib fractures in children, as recorded by Nakayama and co-workers (1989), have been associated with a mortality rate of 5%.

Flail Chest

Instability of the chest wall from unilateral or bilateral multiple rib fractures, or from disruptions of the costochondral junctions, has been estimated to occur in 5% of patients with thoracic trauma, according to the data of LoCicero and Mattox (1989). The force needed to create a flail chest depends on the compliance of the ribs; elderly persons may suffer an unstable chest wall after low-energy impact. whereas, as noted by Nakayama and associates (1989), flail chest occurs in less than 1% of children after severe thoracic trauma.

Paradoxic chest wall motion leads to a reduction in vital capacity and to ineffective ventilation that, along with associated

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Treatment of the unstable chest wall has been somewhat controversial. Previous attempts at external stabilization of the involved segment, including the use of sandbags and towel clips, are now considered obsolete. The so-called internal stabilization using positive-pressure ventilation was introduced by Avery and associates in 1956. This method became the routine method of management until it was superseded by the current use of assisted mechanical ventilation. The reports of Trinkle (1975), Shackford (1976), Clark (1988) and Freedland (1990) and their colleagues and of Battistella and Benfield (2000) stress that prophylaxis and early intervention must be the guiding principles. Mechanical ventilation is instituted for treatment of respiratory insufficiency rather than for its ability to splint chest wall instability, and it is maintained until the patient is able to perform adequate pulmonary ventilation by his or her own effort. Additional discussion of the use of mechanical ventilation is found in Chapter 40. Patients are given aggressive pulmonary physiotherapy with incentive spirometry, are encouraged to cough deeply, and are treated with suctioning, humidification of air, and chest percussion with postural drainage. Bronchoscopy is used promptly to remove retained secretions and to expand areas of collapsed lung.

Operative fixation of flail segments has not gained widespread acceptance, although several techniques have been developed by Haasler (1990) as well as by Paris (1991) and Landreneau (1991) and their colleagues. Recently, Balci and associates (2004) compared the results of open fixation of the multiple fractures resulting in a flail chest in 27 patients to that of two methods of mechanical ventilatory support [i.e., intermittent positive-pressure ventilation (19 patients) and synchronized intermittent mandatory ventilation (18 patients)]. These authors found that 77.8% of the patients who underwent open fixation required short-term ventilatory support postoperatively (mean, 3.1 days). The mortality rate in the surgical group was 11.1%, whereas in the nonsurgical patients, the mortality rate was 27%. Of course, selection of patients for either mode of treatment and other factors must be considered when assessing the results. Nonetheless, it is apparent that surgical fixation is a viable option in the management of a flail chest in an appropriately selected trauma victim.

Survival after flail chest injuries has improved with appropriate ventilatory support and improved pain management. The mortality rate of flail chest of approximately 30% to 40% reported by Shackford (1976) and Thomas (1978) and their associates in the mid-1970s was reduced to 11% to 16% in the late 1980s, as recorded by Freedland (1990) and Clark (1988) and their colleagues. Associated injuries such as underlying pulmonary contusion, as pointed out by Clark and associates (1988), continue to contribute significantly to the persistently high, although reduced, mortality rate.

Landercasper and co-workers (1984) noted that flail chest injuries may have long-term consequences. Impaired pulmonary function has been documented in long-term survivors; 63% of patients reported dyspnea, and 49% of patients reported persistent pain as subjective abnormalities. Objective evidence of chronic disability revealed that 57% of patients had abnormal spirometry and 70% had abnormal treadmill tests. The etiology of these persistent pulmonary abnormalities is unclear, and whether internal stabilization of the chest wall would reduce their incidence is unknown.

Other Bony Fractures of the Chest Wall

Sternal Fractures

Sternal fractures, according to Otremski and co-workers (1990), occur in about 4% of patients involved in major motor vehicle crashes. Older patients and front-seat vehicle occupants involved in frontal collisions are at greatest risk. The fracture is typically transverse and is located in the upper and midportions of the body of the sternum. Diagnosis can be made on physical examination with the identification of localized tenderness, swelling, and deformity. Radiographic confirmation of these fractures requires a lateral view because they are rarely apparent on the anteroposterior chest film (Fig. 70-1). Collins (2000) has noted that CT of the chest can clearly delineate the presence of a sternal fracture as well as injuries of adjacent organs and other skeletal structures. Aslam and colleagues (2002) confirm the value of CT examination, but they advocate the use of MR imaging because it can also detect the presence of sternoclavicular joint disruption. Sternal fractures, like other chest wall injuries, as noted by Buckman and co-workers (1987), are frequently associated with other significant intrathoracic injuries. Injury to the underlying myocardium is not uncommon, but the clinical significance of abnormal test results in hemodynamically stable patients has been challenged by the studies of Wisner and associates (1990). Myocardial injury, however, should be considered in the hemodynamically unstable patient with evidence of anterior chest wall injury.

Treatment of sternal fractures is similar to that for rib fractures; it consists primarily of pain control and appropriate pulmonary hygiene. Sadaba and co-workers (2000)

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When the sternal fracture is severely displaced, open reduction through a midline incision with internal fixation using cross wires is indicated. In the rare patient with a flail sternum that is due to disruption of the costochondral junctions, internal fixation, as suggested by Shackford and colleagues (1976), or external fixation, as recommended by Henley and associates (1991), has been advocated to minimize the need for positive-pressure ventilation.

Scapular and Clavicular Fractures

Fractures of the scapula are uncommon, and they are due to a severe force of impact. This results in an 80% to 90% incidence of associated injuries, according to MaGahan (1980) and Thompson (1985) and their colleagues. Armstrong and Van der Spuy (1984) reported a 10% mortality rate. Because of the high incidence of concurrent brachial plexus injuries, a careful neurovascular examination should be carried out. Treatment consists of shoulder immobilization with subsequent early range-of-motion exercises. Guttentag and Rechtine (1988) have pointed out that surgical repair may be indicated when glenohumeral joint function is impaired.

Clavicular fractures, on the other hand, are common and often the only injury. Clavicular fractures do not compromise ventilation, and treatment by immobilization of the shoulder with a sling and analgesia is effective and usually without complications. Only rarely is operative repair necessary for the management of a severely displaced fracture. Damage to the underlying subclavian vessels or the brachial plexus is rare.

Open Wounds of the Chest Wall: Sucking Wounds of the Chest

These injuries are the result of the loss of an area of the entire chest wall, usually from a gunshot wound (Fig. 70-2). Air can freely flow in and out of the pleural space. The sucking chest wounds present as life-threatening emergencies. Moreover, such wounds are often associated with other devastating intrathoracic injuries. The equilibration of intrathoracic pressure with atmospheric pressure associated with an open pneumothorax leads to collapse of the ipsilateral lung. A patient's inability to ventilate can be temporarily corrected in part by covering the defect. At the scene of the injury, this can be accomplished by covering the wound with a plastic sheet that is taped shut with the exception of a small area of a few inches left unsealed to act as a one-way valve to permit the egress of air from the hemithorax during the phase of exhalation. In the emergency department, the wound can be covered with an impermeable dressing, and a chest tube can be placed to reexpand the lung. Management of large open wounds requires operative d bridement with removal of devitalized tissue and foreign bodies, such as shotgun wadding materials and bone fragments, and closure of the wound. Often, this can be accomplished by mobilizing

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Minor Penetrating Wounds of the Thorax

Many stab wounds and low-velocity gunshot wounds of the chest (80% to 85%) result in only minor injury to the chest wall, pleura, or lung. Pneumothorax and hemothorax are the major complications in this group of patients. However, such wounds should not be taken lightly because associated vascular or cardiac injuries may also be present.

Pneumothorax

Simple Pneumothorax.

Posttraumatic pneumothoraces may not always come to attention during the initial assessment of critically injured victims. Therefore, the chest radiograph should be obtained early in the evaluation and inspected carefully for the presence of lung markings extending to the periphery. Chest tube drainage of posttraumatic pneumothoraces is recommended, even for small collections of air, especially in patients who require positive-pressure ventilation. When a large air leak is present or reexpansion of the lung is difficult, a tracheobronchial injury should be suspected, and bronchoscopy should be performed.

Tension Pneumothorax.

Physical examination in patients with a tension pneumothorax usually reveals severe respiratory distress, distended neck veins, a deviated trachea, and absent breath sounds on the affected side. The radiographic findings are shown in Figure 70-3. The release of a tension pneumothorax is best accomplished by placing a needle into the pleural space to allow pressure in the pleura to equilibrate with the outside air. This relieves the compression of the underlying lung as well as the distortion of vital mediastinal structures. Release of the pressure decreases any compression on the superior and inferior vena cavae and, in association with the expansion of the lung, allows better venous return to the heart.

A very quick preparation of the anterior chest wall is performed using povidone-iodine antiseptic solution. A large-bore, sterile hypodermic needle is then introduced into the second intercostal space in the midclavicular line. The second interspace is easily identified by palpating the angle of Louis, which denotes the junction between the manubrium and the body of the sternum. The second costal cartilage articulates with the sternum at this point. By following the second costal cartilage over onto the rib and delineating the point that corresponds to the midclavicular line just above that rib, safe entry may be gained into virtually any pneumothorax. The introduction of a 14- to 16-gauge large-bore needle allows immediate equilibration between the pleural space and the ambient air. This releases the tension pneumothorax and decreases its lethal nature. A very convenient technique to use in the acute trauma situation is the introduction of an Angiocath (BD Medical Systems, Sandy, UT) as the needle that goes into the tension pneumothorax. By using this, one can take the polyethylene catheter off the introducing needle and leave it in the pleural space. This allows decompression of the tension pneumothorax without having the cutting needle still in the pleura. Large-bore catheters, such as the No. 14 Angiocath, which is readily

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After the pressure has been equilibrated, a chest tube can then be inserted into the thoracic cavity. If the injury to the affected pleural space has only caused a pneumothorax, then appropriate placement of an apical tube attached to a water-seal system may be all that is necessary to reexpand the lung. Tension pneumothorax should be suspected in any patient with chest wall trauma receiving general anesthesia when sudden cardiopulmonary deterioration is associated with a marked increase in the required inspiratory ventilatory pressures. Some surgeons routinely insert thoracotomy tubes in patients with rib fractures, even though no evidence is present of underlying pulmonary injury or a pneumothorax, to prevent the possible occurrence of an intraoperative tension pneumothorax if the injured patient is to undergo a general anesthetic. This is not always necessary, but careful monitoring is necessary, and one should have a low threshold for inserting a tube thoracostomy if the patient's cardiopulmonary status deteriorates.

Hemothorax.

Management of intrathoracic hemorrhage that is recognized in the emergency department requires the use of a large closed-tube thoracostomy. The amount of blood initially obtained and the amount that continues to drain are important criteria for determining whether a thoracotomy is necessary.

Bedside ultrasound may be used in the initial evaluation of the blunt trauma victim to detect traumatic pleural effusions. As reported by Sisley and colleagues (1998), ultrasound can be rapidly performed by the surgeon carrying out the initial evaluation of the injured patient. More commonly, recognition of a hemothorax relies on the chest radiographic findings. On the initial radiographs obtained with the patient in the supine position, the detection of a small hemothorax may be difficult because the blood lies in a horizontal position and may be easily missed. In patients with moderate-sized collections, the chest film may reveal a slight opacification of the affected hemithorax. Initial drainage of the pleural space should be established with a chest tube. If the chest cavity is adequately drained with a No. 36F to 42F chest tube and bleeding has stopped, this should be ample treatment, although a residual clotted hemothorax may need to be treated at a later date when the patient is in a stable condition. Any hemothorax should be evacuated to prevent the formation of a fibrous peel and to reduce the risk for empyema. Video-assisted thoracic surgery (VATS) techniques to evacuate large retained clotted hemothoraces are described in Chapter 32. Evacuation of the clotted hemothorax is not an emergency if bleeding has stopped. VATS drainage of the pleural cavity is best performed 1 to 3 days after injury to reduce the risk for rebleeding from the injured lung. Milfeld and associates (1978) recorded that 33% of 9,000 trauma patients presented with a hemothorax, and 85% of these only underwent drainage procedures; of these, 3.3% required operative evacuation. Other indications for thoracoscopy in thoracic trauma are listed in Table 70-3.

Sources for intrathoracic bleeding include intercostal vessels, pulmonary parenchymal injuries, major pulmonary vessels, and injury to the heart or great vessels. Most pulmonary parenchymal injuries can be managed with a tube thoracostomy simply by evacuating the hemothorax and allowing the lung to reexpand. The pulmonary distention associated with reexpansion of the lung tamponades parenchymal bleeding after most injuries. If a thoracotomy is needed because of continued bleeding as a result of an injury to one or more intercostal vessels or to an internal mammary artery, adequate exposure of the entire hemithorax is required. Battistella and Benfield (2000) have reported that in patients with large chest wall injuries in whom the bleeding may be diffuse and difficult to localize, ligation of the intercostal vessels near their origins may be a life-saving maneuver. If bleeding from intercostal vessels occurs at the level of the intervertebral foramen, control may require laminectomy; packing of the foramen should be avoided because it may place patients at risk for spinal cord injury and subsequent paraplegia.

Pulmonary Contusion

Pulmonary contusion, which usually results from blunt trauma, consists of hemorrhage into the alveolar and interstitial spaces (Fig. 70-4). Contusions may also result from penetrating injury, especially high-velocity missile wounds. Although Nakayama and co-workers (1989) have reported that pulmonary contusions can occur as isolated injuries in children, in adults, they are typically associated with other injuries and have an overall mortality rate of 22% to 30%, as has been recorded by Besson and Saegesser (1983) and Stellin (1991). Many contusions are small and contribute little to patient morbidity, but large contusions lead to hypoxia and the need for mechanical ventilation. The increased use of CT scanning in the evaluation of acute chest trauma, as described by Wagner and Jamieson (1989) and Trupka and colleagues (1997), has improved the sensitivity

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Pulmonary contusion should be suspected in any patient with major chest wall injury; it can be confirmed by radiologic evaluation. Most clinically significant contusions appear on the initial chest radiographs and may be difficult to differentiate from aspirations. According to Battistella and Benfield (2000), several characteristics aid in distinguishing between the two entities. Pulmonary contusions are usually present on the initial film. The first posttrauma chest radiograph of patients suffering from aspiration may be normal, with the development of an infiltrate occurring during the next several hours. Infiltrates that are due to aspiration may be confined by anatomic pulmonary segments; those associated with pulmonary contusions outline the area of impact that may or may not correspond to the lobar or segmental anatomy of the lung. Among the most helpful features that permit distinction between contusion and aspiration pneumonia is the nature of the tracheobronchial secretions: aspiration is associated with copious secretions that may contain particulate matter, whereas contusions may be associated with bloody secretions. Initial care for both conditions is supportive and is based on serial physiologic measurements and sequential radiographs. Patients with aspiration, however, often benefit from early bronchoscopy.

Battistella and Benfield (2000) recommend that treatment of patients with pulmonary contusions includes ventilatory support, as needed, based on clinical and laboratory findings. Associated injuries to the chest wall, pleura, and lungs should be identified and treated. Fluid administration should be adequate to resuscitate shock; oxygen delivery and consumption should be made optimal. Because of increases in capillary endothelial permeability associated with pulmonary contusion, some authors have encouraged fluid restriction. Judicious administration of fluids with cardiovascular monitoring is appropriate, particularly in elderly patients; however, fluid restriction and the administration of diuretics in the treatment of pulmonary contusion are appropriate only in patients with evidence of fluid overload. Filling pressures should be returned to normal, using either blood products or crystalloid or colloid solutions, to maintain adequate oxygen delivery. Massive pulmonary contusions associated with large shunt fractions and hypoxemia with differential lung compliances between the affected and unaffected lungs can be managed with double-lung ventilation or, rarely, with resection of the affected lung tissue.

Pulmonary Hematoma

Pulmonary hematoma is another condition that may be difficult to differentiate from pulmonary contusion because of the surrounding intraparenchymal hemorrhage. However, 24 to 48 hours after the injury, a hematoma typically develops into a discrete mass with distinct margins. CT scans can be helpful in distinguishing between contusion and hematoma. In most cases, the hematoma itself does not interfere with gas exchange and with time is resorbed spontaneously. Only rarely may these hematomas become secondarily infected and present as an abscess requiring drainage.

ACUTE INJURIES REQUIRING URGENT THORACOTOMY

About 85% of the chest trauma victims who arrive alive at a trauma center can be managed without a thoracotomy. Observation, adequate volume resuscitation, and occasionally respiratory support are the only treatment required, as noted by Washington (1985) and Richardson (1996) and their co-workers. The remaining 15% require urgent thoracotomy

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Major Pulmonary Parenchymal Injury

Parenchymal injury may occur with either penetrating injuries (stab wounds, gunshot or shotgun wounds) or as the result of severe blunt trauma. The injury may be fatal initially or may be of varying degrees of lesser severity so that the patient may reach a treatment center alive.

Initial evaluation and institution or continuation of the appropriate resuscitative measures are accomplished as discussed previously. Radiographs of the chest are obtained if possible, and some groups, including Sisley and associates (1998), suggest that the use of ultrasound examination of the chest is quite informative. Closed-tube drainage is established if a pneumothorax or hemothorax is present. Bronchoscopy is done if possible when a massive air leak or massive hemoptysis is present. A bronchial blocker may be used to contain excessive bleeding from the affected lung, as suggested by Inoue and associates in 1984 and more recently by Nishiumi and colleagues (2001).

At times, an immediate thoracotomy must be done in the emergency room in an attempt to save the patient's life; this is often successful in patients with penetrating trauma but rarely so in patients with blunt trauma. The main maneuvers are control (occlusion) of the hilum of the injured lung and open cardiac massage as needed; adequate fluid replacement and ventilatory support are mandatory.

The incision of choice is an anterolateral thoracotomy or, at times, a median sternotomy. The initial step is occlusion of the hilum either by cross-clamping with the use of a Satinsky vascular clamp, as suggested by Wall and co-workers (1994), or the use of a Rummel tourniquet, as described by Powell and associates (1990). Before control of the hilar structures, care must be taken not to increase the endobronchial gas pressure to greater than 60 mm Hg; this is best ensured by using a ventilatory system with a pop-off valve set at 40 cm H₂O. The reason for strict control of the endobronchial gas pressure is prevention of the possibility of producing an air embolism (if it has not already occurred).

Air Embolism

Graham and colleagues (1977) pointed out that when endobronchial gas pressure exceeds 60 mm Hg in patients with adjacent injured (open) bronchiolar and pulmonary venules, the gas (air) will readily pass into the pulmonary venous system and will be transported to the left ventricle. As the gas is pumped out into the systemic circulatory system, air embolism to the coronary arteries, ascending aorta, and cerebral circulation will occur. In a conscious person, an air embolism may lead to abrupt cardiovascular collapse, seizures, or sudden death. Treatment consists of: (a) occlusion of the hilar structures of the injured lung, (b) placement of the patient in the Trendelenburg position, (c) aspiration of air from the apex of the left ventricle and aorta, (d) open cardiac massage, and (e) maintenance of adequate diastolic blood pressure. It has also been suggested by Swanson and Trunkey (1989) that 1 mL of 1:1000 epinephrine be injected intravenously or placed down the endotracheal tube to provide an -adrenergic effect that is thought to drive air out of the microcirculation. The latter authors noted that with aggressive treatment, 55% of patients with air embolism from penetrating trauma and 20% of patients with air embolism from blunt trauma could be salvaged. In patients who survive but remain comatose, the use of hyperbaric oxygenation occasionally may resolve the process.

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Management of Pulmonary Lacerations at Thoracotomy

Parenchymal Wounds and Lacerations

Most severe or so-called deep lacerations are located in the outer one half to two thirds of the lung tissue distal to the hilum and lend themselves to simple ligature (rare), stapled wedge resection, tractotomy, or lobectomy. The more central lesions usually require lobectomy or, infrequently, pneumonectomy (5% to 8%) because of vascular injury in or near the hilar area.

Tractotomy.

A tractotomy was initially described by Wall and associates (1994) at the Ben Taub General Hospital in Houston, Texas. The wound tract of the through-and-through injury or deep laceration is exposed by dividing the bridge of lung tissue between aortic clamps. Exposed vascular and bronchial lacerations are ligated with interrupted figure-of-eight No. 4-0 polypropylene sutures; the lung tissue in the clamps is then oversewn with a continuous suture of the same material. The tractotomy is left open. Asensio and colleagues (1997) modified the procedure with the use of stapling instruments to secure the parenchymal incision; subsequently, other surgeons have oversewn the original staple lines (Fig. 70-5). In the reports of Wall (1994), Velmahos (1999), Karmy-Jones (2001), Gasparri (2001) and Cothren (2002) and their colleagues, tractotomies have been quite successful, with a mortality rate varying from 0% to 14% (Table 70-6). However, morbidity is significant and occurs in one third to two thirds of the patients so treated. Most of the complications are infections; others are ischemia of the stapled tissue, recurrent bleeding, occasional bronchopleural fistula, and pulmonary torsion [the latter complication was recorded by Velmahos and associates (1998)]. Ventilatory support is often needed initially, but in the long run, the patients do well.

Major distal parenchymal deep lacerations associated with adjacent lung damage that cannot be managed by a tractotomy require lobectomy (Fig. 70-6); although the mortality rate is generally higher, the complication rate is generally lower. However, the data cannot be easily compared in the multiple reports, and in a given report, the actual data may be difficult to interpret because of patient selection and other factors.

Lesser lacerations may be readily managed by a stapled wedge resection, and the results seen after such procedures are generally better than in the aforementioned groups.

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Proximal Pulmonary and Hilar Injuries

The small number of patients who survive severe injuries to the hilar or proximal vessels and bronchi (exclusive of isolated tracheobronchial injuries as subsequently discussed) are in precarious physiologic condition. Fortunately, according to Carrillo and colleagues (1994) and Wiencek and Wilson (1988), only 6% to 15% of the patients with deep lacerations fall into this category. Despite vigorous resuscitation, these patients are hypotensive, hypothermic, and acidotic, and they may or may not have suffered an air embolism. Lobectomy is the treatment of choice if possible and is better tolerated than is an emergency pneumonectomy. Repair of the vessels is possible at times, but if it cannot be done expeditiously, Richardson and co-workers (1996) suggest that a stapled pneumonectomy be carried out promptly. It is advisable to use two staple lines when possible. Unfortunately, when a pneumonectomy is required (in 5% to 8.5% of this patient group), the mortality is high; death on the table is not infrequent; and of those who initially survive the resection, there is, as a rule, a 50% or greater mortality rate (see Table 70-6). The cause of the high mortality rate after pneumonectomy is most often either continued elevated pulmonary artery pressure due to microvascular vasoconstriction with subsequent right heart failure that cascades to left ventricular dysfunction and eventual death or the development of refractory ARDS. Richardson and colleagues (1996) noted that the former (continued pulmonary hypertension) may be the result of shock-induced thromboxane and leukocyte activity on the pulmonary circulation, as suggested by Wong and associates (1984) and Wilson (1972), respectively. Nurozler and co-workers (2001) have suggested that nitric oxide inhalation may be of benefit as a vasodilator in this situation, as likewise reported by Mathisen and coinvestigators (1998) in patients with ARDS after tracheal sleeve pneumonectomy.

Of interest is that in all the various categories of repair, patients with major injuries following blunt trauma have a higher mortality rate than do those with penetrating injuries. Of course, appropriate mechanical ventilation and reduced fluid replacement are indicated in all these patients, as is intensive postoperative care (see Chapters 39 and 40). Other complications (mostly nonfatal) of these resections are postoperative pneumonia, respiratory failure, bronchopleural fistula, cardiac arrhythmias, postoperative hemorrhage, hypothermia, coagulopathy, clotted hemothorax, and empyema.

The major indications for repeat or late thoracotomy are listed in Table 70-7. Depending on the patient's general condition at the time of a necessary reoperation, a VATS procedure may be quite satisfactory, and these situations are listed in Table 70-8.

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Other Complications of Thoracic Trauma

Tracheobronchial tears and avulsion, tracheoesophageal and bronchoesophageal fistula, diaphragmatic injuries, chylothorax, tracheal and bronchial stenosis, and lung herniation may occur as early or late complications of trauma. Tracheobronchoesophageal fistula, diaphragmatic injuries, and chylothorax are discussed, respectively, in Chapters 138, 74, and 63, and are not be repeated here.

Tracheobronchial Injuries

Blunt and penetrating injuries of the cervical portion of the trachea are more common than such injuries of the intrathoracic portion of the trachea or of the major bronchi. Peripheral bronchial injuries, on the other hand, are not uncommon with penetrating thoracic injuries and at times are associated with major hemoptysis or air embolism. The management of the latter injuries has been discussed previously.

Blunt Intrathoracic Tracheal and Major Bronchial Injuries

The mechanisms of tracheal or major bronchial tears or complete disruptions are thought to be due to (a) rupture of the membranous portion of the trachea as the result of a rapid increase in intraluminal pressure within the structure caused by sudden thoracic compression in a patient with a closed glottis, (b) disruption at a point of fixation (i.e., the carina) due to the shearing force as seen with rapid deceleration, and (c) laceration or complete avulsion as the result of lateral traction on the lung caused by crushing chest injuries. Of interest, Deslauriers (1987) noted that 80% of blunt traumatic tracheobronchial tears occur within 2.5 cm of the tracheal carina; the left upper lobe bronchus is, however, not infrequently involved, but more distal lobar and segmental bronchi are rarely affected.

Incidence.

Bertelsen and Howitz (1972) reported that injury to the trachea or major bronchi was found in 0.03% in an autopsy study of 1,178 trauma deaths. The actual number of patients with these injuries that arrive alive at definitive treatment centers is unknown, although Stewart and associates (1997) noted 4 patients with these injuries in 2,455 patients with chest injuries over a 10-year period (an incidence of 0.16%). Richardson and colleagues (1996) also believe that the number of such cases seems to be increasing.

Diagnosis.

Most of the patients with a tracheobronchial tear or disruption present with a pneumothorax and its associated findings. Subcutaneous emphysema is common as is airway distress. With the initiation of closed-tube drainage, the air loss, despite the reexpansion of the lung, usually continues to be excessive in amount. This should alert the clinician to carry out an emergent bronchoscopic examination. According to Hara and Prakash (1989) and Velly and colleagues (1991), bronchoscopy is positive in nearly 100% of the cases. At times, failure of the lung to expand is observed, or rarely the fallen lung sign (collapse of the lung toward the lateral chest wall), as described by Unger and associates (1989), is observed. Infrequently, hemothorax or hemoptysis is seen, and either is indicative of associated vascular injury, as noted by Rocco and Allen (2001). Unfortunately, at times [17% of instances according to Velly and co-workers (1991)], the injury may be missed owing to initial expansion of the lung and discontinuation of the air leak. Subsequent atelectasis occurs that may or may not be recognized. When this is discovered early, successful repair may be accomplished (Fig. 70-7). In the event this opportunity was missed and the tear was incomplete, varying degrees of stenosis of the distal bronchial lumen occur with healing, and subsequent distal intermittent or persistent infection with associated secondary parenchymal damage occurs. On the other hand, when complete disruption occurs, it most often results in total obstruction of the proximal and distal ends of the divided bronchus. Under these circumstances, infection rarely occurs in the distal lung, and the obstructed bronchial tree becomes filled with a thick, tenacious, mucoid material. This can be readily aspirated at the time of later repair. Excellent ventilatory function can be expected when bronchial continuity is reestablished within a few weeks up to 6 months after the initial injury, although both Benfield (1958) and Eastridge (1970) and their co-workers have reported good functional results after late repairs. More often than not, although complete restoration of

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Treatment.

Ideally, operative repair should be done as soon as feasible after the injury. With passage of time, increasing scar tissue forms, which renders isolation of the structures increasingly difficult.

Anesthesia is conducted through a double-lumen endotracheal tube or a single-lung tube into the left bronchus for one-lung anesthesia when the injury is in the right bronchial tree. A standard posterolateral thoracotomy is used; a right-sided approach is used for repair of the trachea and the right bronchial tree. Likewise, a right-sided approach is the procedure of choice when an injury of the proximal left main-stem bronchus is well above the takeoff of the left upper lobe bronchus and no vascular injury is suspected. Other injuries of the left bronchial tree are approached from the left side. In either case, the site of injury is identified, and the margins of the injury are d brided as necessary. Repair of the laceration or anastomosis of a completely divided bronchus is done in the standard fashion (see Chapter 28) with interrupted sutures of No. 0-3 or 0-4 Vicryl. The suture line is routinely covered with adjacent tissues or a pedicled intercostal muscle flap, making sure all periosteal tissue has been removed because ossification from retained periosteum can result in late stenosis of the area, as noted by Deeb and associates (2001). Patients undergoing a late repair who have destroyed, infected lung distal to the site of injury require a standard resection of the distal involved parenchyma. If the infectious process is not severe, dilation of

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Intubation Injuries of the Trachea

A less common but nonetheless important tracheal injury is laceration of the membranous wall of the trachea that occurs during intubation. On the whole, these injuries are rare. In a recent series of such injuries reported by Carbognani and associates (2004), less than one fourth of these lacerations were recognized intraoperatively, and most were identified only 1 to 5 hours after the injury had occurred. The possibility of a tracheal injury only was recognized as the result of the occurrence of dyspnea, subcutaneous emphysema, or hemoptysis. After the injury was verified by bronchoscopy, the aforementioned authors used three approaches in their treatment of these injuries. Membranous tears less than 2 cm in length were managed conservatively with antibiotic administration and supportive care without surgical intervention. A successful outcome occurred in all three patients in whom this therapeutic approach was used. The longer tears, especially those that extended into a main bronchus, were repaired through a right thoracotomy. Subsequently, in more recent years, tears confined to the trachea were repaired using a transcervical transtracheal approach with closure of the membranous laceration with No. 4-0 polydioxanone continuous suture and the transverse anterior tracheal incision with interrupted No. 3-0 sutures of the same material. Satisfactory healing occurred in all of their patients. The latter approach was suggested originally by Angelillo-Mackinlay (1995). This transcervical transtracheal aprpoach also has been used with success by Mussi (2000) and Lancelin (2000) and their colleagues.

Tracheal and Bronchial Stenosis

Primary stenosis of an area of the tracheobronchial tree is a rare event when it occurs after blunt or penetrating trauma. Of 140 patients undergoing T-tube placement for the management of stenosis of the trachea at the Massachusetts General Hospital, as reported by Gaissert and associates (1994), only two of the stenoses were due to previous external trauma. Primary traumatic bronchial stenosis is likewise rare and is the result of a missed bronchial tear or avulsion incurred during a severe blunt traumatic event, as just previously noted. With the exception of malignant strictures, most stenotic lesions of the trachea or bronchi are iatrogenic in origin (i.e., endotracheal tube dependence, sleeve resections, and initial repairs of bronchial traumatic injuries). Postintubation injuries of the trachea are as a rule the most common, and this subject has been discussed fully in Chapter 77. Stenotic lesions of a bronchus are now more frequently seen in posttransplantation patients, and the management of this complication is briefly discussed in Chapter 95.

The principal management of such stenotic lesions [other than a rare bronchial resection and reanastomosis, such as a sleeve resection of the bronchus intermedius, as recently reported by Paulson and co-workers (2003)] is dilation and the placement of a bronchial or tracheal stent.

Tracheal stents are primarily made of silicone and come in many sizes and configurations. Tracheal T tubes and their placement are discussed in detail in Chapter 75. Other stents (i.e., TY tube and the bifurcated Y stent with or without tracheal stomas) and their endotracheal placement have been described by Nesbitt and Welsh (1998) as well as by Gaissert and Patterson (2002).

Bronchial stents may be rigid silicone stents or flexible or self-expanding wire stents (Table 70-9). It is important that a specific stent be chosen for the location of the stenosis and to ensure palliation of the pathology present. The techniques of insertion vary with the stent selected and may require either an anesthetized or an awake patient with or without fluoroscopic guidance. Initial endobronchial dilation is essential in the stenting process. When properly placed and maintained, the long-term results of the use of a stent are usually excellent.

Lung Herniation after Blunt Trauma

Numerous authors, including Jacka and Luison (1998) and Reardon and colleagues (1998), have recorded that the occurrence of a lung hernia was first reported by Roland (1499). A classification of these hernias was initially suggested by Morel-Lavalle (1845). The classification was simple: congenital or acquired. The latter hernias were subclassified as spontaneous-pathologic or traumatic (the latter being the more common type).

Congenital hernias are most often found in the supraclavicular space and infrequently at one of the anterior costochondral junctions or laterally in an intercostal space owing to the lack of development of an intercostal muscle. Weissberg and Refaely (2002)

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Traumatic Lung Herniation

Traumatic lung hernias may occur after nontraumatic penetrating injuries such as surgical incision, and this type was considered the more common of the two types of noncongenital herniations, as reported by Forty and Wells (1990). However, it now appears that blunt trauma occurring during motor vehicle crashes to patients with shoulder-harness seatbelt restraints (i.e., three straps) in place is the more common cause. Araj vi and colleagues (1987) described the abdominal injuries sustained by seatbelt users, and Araj vi and Santavirta (1989) evaluated chest injuries with fatal outcomes in seatbelt wearers; the cause of death was most often unrelated to the seatbelt itself. Lung contusions and lung lacerations occurred, but the incidences were low. Sternal fractures were the most common fractures, but rib fractures were not infrequent. The incidence and site of the rib fractures were influenced by the side of the car the individual was sitting in as well as the direction (i.e., right to left or left to right) of the shoulder seatbelt harness. In 14 drivers sitting on the left side with the strap passing from the left shoulder to the right side of the lower horizontal belt, fractures of the right rib cage (most often in the costochondral junction area) were sustained in 78.6%, and in only 28.6% were fractures located in the left rib cage. In 29 passengers sitting on the right side with the strap passing from right to left, the incidence of the fractures was reversed: 75.7% were in the left chest cage and 48.3% in the right chest cage. May and associates (1995) noted lung herniation at the site of the seatbelt fractures and considered this another aspect of the seatbelt syndrome, so named by Garrett and Braunstein in 1962. As noted, the site of the rib fractures is most often along the costochondrosternal junction, but they may occur in other areas of the chest wall as well (Fig. 70-8). The lung herniation may be identified early, or its identification may be delayed for months to years. Symptoms are often minimal, but the chest wall hernia is accompanied by a localized soft bulge that changes its shape paradoxically with the respiratory cycle. The actual hernia may not vary much in size because of incarceration of a portion of the lung within the hernial sac.

The diagnosis may be made by standard radiographs or by CT examination (Fig. 70-9). Recent cases have been described by Filosso and co-workers (2001a, 2001b) and Jacka and Luison (1998).

Repair of these hernias consists of reduction of the lung back into the pleural space and closure of the defect with a prosthetic patch such as polytetrafluoroethylene cloth or a Gore-Tex patch (W.L. Gore and Associates, Inc., Flagstaff, AZ). The reported results have been excellent. At times, the chest wall opening may be closed by simple suture approximation of the edges of the defect. Reardon and associates (1998) have recorded a successful video-assisted repair of a traumatic intercostal hernia in an injured motorcyclist.

Lung hernias due to penetrating trauma, as noted, are usually from previous incisions into the chest, but the numbers

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Spontaneous Lung Herniation

A spontaneous lung hernia in actuality is a variant of a traumatic hernia; it occurs after self-inflicted trauma caused by coughing, sneezing, or abnormal body motion. The spontaneous lung hernias occur in the anterior wall as a rule, on either side with equal frequency and in older persons, and are seen exclusively in men as recorded in the recent review of 16 patients in the world literature by Brock and Heitmiller (2000) (Table 70-10). Most of the men are smokers, and they present with anterior chest wall pain and chest wall ecchymosis. Radiographs reveal the fracture site, which is usually in the lower rib cage (>93%). Surgical repair is usually done by a primary repair (44%) or by a prosthetic patch applied to the defect (31%), although in one patient, no repair was attempted. The prognosis, however, after repair is quite satisfactory. Weissberg and Refaely (2002) recorded the development of a spontaneous supraclavicular hernia in a middle-aged woman with chronic obstructive pulmonary disease (COPD); whether this was a true spontaneous hernia or only a congenital one that was exacerbated by the patient's coughing remains undetermined.

Numerous techniques of closure of these chest wall defects after reduction of the lung hernia have been described. Direct suture repair and the use of a prosthetic material to cover the defect have been used successfully when appropriately selected.

FOREIGN BODY PULMONARY EMBOLUS

On rare occasion as the result of a gunshot wound of the abdomen or of an extremity, a bullet or metal fragment gains entrance into a major vein and is carried to the right ventricle. A typical radiographic finding is a blurred, out-of-focus object seen in the heart while all other structures are in focus. With changes in the position of the body, the object may embolize into one of the pulmonary arteries, as noted by Straus (1942) and Hafez and associates (1983). Total occlusion of the vessel distal to the object may occur, but this event is very uncommon. Nonetheless, the foreign body should be removed, but this is not of emergent priority. Unfortunately, often in the past, the object was believed to be fixed in the involved vessel. However, when the patient was placed in the appropriate opposite lateral decubitus position and the involved pulmonary artery explored, the foreign body was no longer present in the exposed, uppermost pulmonary artery. The object had been dislodged by gravity and had fallen into the pulmonary artery in the opposite dependent hemithorax. To prevent such an untoward event, the patient must be operated on in the supine position with the opposite hemithorax and the uninvolved pulmonary artery maintained at a higher level than the hemithorax with the involved pulmonary

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Finally, small metallic foreign bodies located in the pulmonary parenchyma generally need not be removed.

APPENDIX A

Glasgow Coma Score

The GCS is scored between 3 and 15, 3 being the worst, and 15 the best. It is composed of three parameters: Best Eye Response, Best Verbal Response, Best Motor Response, as given below:

Best Eye Response (4)

• No eye opening

• Eye opening to pain

• Eye opening to verbal command

• Eyes open spontaneously

Best Verbal Response (5)

• No verbal response

• Incomprehensible sounds

• Inappropriate words

• Confused

• Orientated

Best Motor Response (6)

• No motor response

• Extension to pain

• Flexion to pain

• Withdrawal from pain

• Localising pain

• Obeyxhts commands

Note that the phrase GCS of 11 is essentially meaningless, and it is important to break the figure down into its components, such as E3V3M5 = GCS 11.

A Coma Score of 13 or higher correlates with a mild brain injury, 9 to 12 is a moderate injury and 8 or less a severe brain injury.

From: Trauma.org website: http://www.trauma.org/index.html

APPENDIX B

Injury Severity Score

The Injury Severity Score (ISS) is an anatomical scoring system that provides an overall score for patients with multiple injuries. Each injury is assigned an Abbreviated Injury Scale (AIS) score and is allocated to one of six body regions (head, face, chest, abdomen, extremities (including pelvis), external). Only the highest AIS score in each body region is used. The three most severely injury body regions have their score squared and added together to produce the ISS score.

An example of the ISS calculation is shown below:

The ISS score takes values from 0 to 75. If an injury is assigned an AIS of 6 (unsurvivable injury), the ISS score is automatically assigned to 75. The ISS score is virtually the only anatomical scoring system in use and correlates linearly with mortality, morbidity, hospital stay, and other measures of severity.

Its weaknesses are that any error in AIS scoring increases the ISS error, many different injury patterns can yield the same ISS score, and injuries to different body regions are not weighted. Also, as a full description of patient injuries is not known prior to full investigation and operation, the ISS (along with other anatomical scoring systems) is not useful as a triage tool.

From: Trauma.org website:http://www.trauma.org/index.html

APPENDIX C

Abbreviated Injury Scale

The AIS is an anatomical scoring system first introduced in 1969. Since this time it has been revised and updated against survival so that it now provides a reasonably accurate ranking of the severity of injury. The latest incarnation of the AIS score is the 1990 revision. The AIS is monitored by a scaling committee of the Association for the Advancement of Automotive Medicine.

Injuries are ranked on a scale of 1 to 6, with 1 being minor, 5 severe, and 6 an unsurvivable injury. This represents the threat to life associated with an injury and is not meant to represent a comprehensive measure of severity. The AIS is not an injury scale, in that the difference between AIS1 and AIS2 is not the same as that between AIS4 and AIS5. There are many similarities between the AIS scale and the Organ Injury Scales of the American Association for the Surgery of Trauma.

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Appendix

A. Glasgow Coma Scale. From Teasdale G, Jennett B: Assessment of coma and impaired consciousness. Lancet 2:81, 1974.

B. Injury Severity Scale. From Baker SP, et al: The injury severity score: a method for describing patients with multiple injuries and evaluating emergency care. J Trauma 14:187, 1974.

C. Abbreviated Injury Scale. From Copes WS, Sacco WJ, Champion HR, et al: Progressing in Characterising Anatomic Injury. In Proceedings of the 33rd Annual Meeting of the Association for the Advancement of Automotive Medicine. Baltimore, 205.