CHAPTER 38 OPERATIVE MANAGEMENT OF PULMONARY INJURIES: LUNG-SPARING AND FORMAL RESECTIONS

Juan A. Asensio, Luis Manuel García-Núñez, Patrizio Petrone, David King, Ricardo Castrellon, Dominic Duran, Alexander D. Vara, John S. Weston, Donald Robinson, Louis R. Pizano

Chest injuries were reported in the Edwin Smith Surgical Papyrus¹ as early as 3000 BC. Ancient Greek chronicles reveal examples of penetrating chest wounds and pulmonary injuries; the Greeks had anatomic knowledge and were cognizant of the thoracic structures and the position of the lungs inside the hemithoracic cavities. In Homer’s Iliad,² there is a vivid description of the death of Sarpedon by Patroclus: “[H]e penetrated him with his spear and while taking it out, his diaphragm came along with it….” Homer² emphasized the importance of the diaphragm, anatomically related to the lungs and the “beating heart.” While pneumothorax was a well-known entity, the Greeks realized the special problems related to thoracic penetration and considered open chest wounds fatal. Although the success of these early treatment modalities remains unknown, it seems that during Olympic competitions, physicians in ancient Greece were at least able to identify potential lethal chest injuries, and most likely attempt their treatment.¹^–³

Pausanias,³ a Greek traveler during the height of Roman rule, described a penetrating injury to the chest, inflicted to Creugas of Epidamnus by Damoxenus of Syracuse, with the presence of what seems to be an obvious pulmonary injury. Eusebious described in Evangelical Preparation, the match of Cleomedes of Astypalaia against Ikkos of Epidauros: “Why did they deify Cleomedes? For opening his opponent’s rib, inserting his hand inside and eviscerating his lung…”¹^–³

Galen (130–200 AD), one of the most prominent physicians of antiquity described packing of chest wounds in gladiators with thoracic and possibly lung injuries.^1,⁴ A description of a lung injury was found in a treatise of Theodoric, in 1226: “[W]hile I was living in Bolonia, a certain Domicellus, a Bolognan of normal birth was, cured by the hand of Master Hugo, part of his lung being torn away and Master Roand was there to witness it…”^5,⁶

Even in the ancient world, most of the therapeutic modalities for chest wounds and traumatic pulmonary injuries were developed during wartime. In 1635, Alvar Nuñez Cabeza de Vaca,⁴ a Spaniard, while traveling from the Mexican northern territory to the capital of Nueva España (Mexico City), was captured by Indians. A wounded member of the tribe was brought to Cabeza de Vaca. With his assistant Esteban, Cabeza de Vaca made an incision to remove an arrowhead embedded in the man’s chest, and sutured the wound. His innovation in surgical management won freedom from his captors for him and his friend.

During the 16th century, a few contributions were made to the management of traumatic pulmonary injuries. Ambroise Paré ⁵ treated penetrating thoracic injuries by placing a scalding mixture of oil and treacle in the wound as the first dressing. John Hunter’s⁵ initial experience dealing with penetrating thoracic injuries, caused by smooth-bore muskets firing round lead balls, led him to recognize that projectile velocity is a determinant factor dictating severity of the injury. Jean-Dominique Larrey and Pierre Joseph Desault^5,⁶ made important contributions to the surgical procedure known as “débridement” for the management of chest wall lacerations; however, the surgical treatment of intracavitary injuries did not evolve significantly during this time. Although Larrey^5,⁶ described operative techniques for dealing with penetrating cardiac injuries, his contributions to the management of pulmonary injuries are not remarkable.

In 1822, William Beaumont, better known for “Beaumont’s gastric fistula observations” than for his management of life-threatening chest injuries, treated a patient that sustained a gunshot wound to the chest and described the nature of the injury: “fracturing and carrying away the anterior half of the 6th rib, lacerating the lower portion of the left lobe of the lung, diaphragm and penetrating the stomach.”⁶ During the 18th century, controversies emerged surrounding the benefit of surgical manipulation in the treatment of traumatic thoracic and pulmonary injuries. In Germany, Auenbrugger⁶ said: “opening the chest caused asphyxia because the lung collapsed.” Dupuytren,⁶ a famous French surgeon, in 1835 personally developed empyema. Although prepared to undergo a surgical intervention for its treatment, he decided, based on knowledge about Auenbrugger’s description of “open-chest asphyxia” that “he would rather die at the hands of God than of the surgeons”; he survived for 12 days.

In the 1840s, the French Academy of Medicine ⁶ studied the treatment of empyema to produce guidelines for its treatment based on war experiences. In the 18th century, Hewson⁶ called attention to the mechanism of pulmonary rupture after blunt trauma to the chest, while in 1886, Ashurt⁶ described rupture of thoracic viscera without rib fractures. In 1889, Holmes, consulting surgeon to St. George’s Hospital in London, said: “All penetrating wounds to the chest, if small, should be closed at once and dressed antiseptically. If the wound is large and the lung evidently extensively injured, it is a better plan not to close the external wound completely, but to insert a large drainage tube to carry off the blood into an antiseptic dressing and so prevent its accumulation in the pleural cavity.”⁶ In 1897, Duval⁶^–⁸ described median sternotomy incision, which he described as a thoracolaparotomy, while in 1906, Spangaro,⁶^–⁸ an Italian surgeon, described the left anterolateral thoracotomy incision. These incisions remain important contributions to the trauma surgical armamentarium to manage traumatic pulmonary injuries.

In 1916, Mentz ^6,⁸ reported removal of foreign matter from the lung and pointed out the relative safety of thoracotomy. The treatment of thoracic wounds in World War I started with many of the basic principles described in the 19th century. Specifically, hemothoraces were treated expectantly. Hemothoraces were not aspirated in the belief that tamponade of the injured lung had occurred. However, when surgery was required for thoracic injury, it was aggressive and largely successful following principles of air-tight closure for wounds and removal of foreign bodies. In contrast to their surgical counterparts in the German Army, American surgeons with the Allied Expeditionary Force used positive-pressure anesthesia and a nitrous oxide/oxygen mixture, while practicing early thoracotomies following the principles for good exposure injuries, resection of affected anatomic structures, suture ligature, and irrigation of the thoracic cavity.^7,⁸ Thoracotomies were closed air tight, traumatic wounds excised, and no drains were placed. This technique was associated with a 9% decrease in mortality.^7,⁸ During this time Grey-Turner, Miles, Gask, Duval, and Bastianelli⁹ defined the technique of pulmonary decortication for the treatment of retained hemothorax after traumatic lung injuries.

In World War II, because of increased awareness of the high incidence of complications associated with hemothorax after wounding, an approach of aggressive conservatism for the management of hemothorax was adopted.^7,⁸ Thoracentesis was used repeatedly, until the thoracic cavity was totally evacuated. No air was permitted to enter the thoracic cavity. The injured lung was allowed to re-expand and tamponade bleeding, in hopes of returning pulmonary function to normal levels. Water-sealed intercostal catheters were placed in patients with tension pneumothoraces. Thoracotomy was reserved for continued hemorrhage or significant air leaks; additional indications included thoracoabdominal wounds, mediastinal injuries, traumatic thoracotomy, “the sucking chest wound,” and removal of foreign bodies. Overall mortality with this treatment of war chest wounds was reported as 8%.^7,⁸

The Korean conflict created newer challenges for surgeons.^7,⁸ Terrain characteristics and unfavorable tactical conditions, coupled with numerous incoming casualties, overloaded mobile army surgical hospitals (MASH units). Conservative management of traumatic hemothorax was thus a therapeutic strategy extremely suited to these conditions. Eighty percent of casualties from the Korean War were managed by repeated thoracentesis alone; however, there was limited experience with the use of chest tubes for drainage of hemothorax. The introduction of more advanced resuscitative techniques helped to compensate somewhat for the problems encountered with forward treatment.^7,⁸

In the Vietnam conflict, chest tube drainage for pulmonary injuries and hemothorax was widely practiced. Casualties were evacuated early at the hospital directly from combat. Well-organized “trauma centers,” with cardiothoracic surgical capabilities operated under strict resuscitative protocols.^4,^5,^7,⁸ Given the success of tube thoracostomy in this setting, early thoracotomy was indicated for fewer patients with hemothorax, although the former indications for its use remained. Tube thoracostomy remains the cornerstone for the treatment of traumatic hemothorax or pneumothorax, as well as for most traumatic injuries to the lung.¹⁰

Recent awareness based on civilian and military experience has led to the recognition that complex procedures, such as anatomic resections and pneumonectomy in unstable patients, are poorly tolerated and potentially daunting.⁷ Critically injured patients often develop hypothermia, acidosis, coagulopathy,¹¹ and dysrhythmias,¹²^–¹⁴ resulting in irreversible physiologic injury. Control of such damage is also part of the trauma surgeon’s armamentarium to deal with thoracic injuries.¹⁵^–¹⁸ Progress in treating severe pulmonary injuries in critical patients has thus far relied on finding shorter, simpler, lung-sparing techniques, such as wedge and nonanatomic resections, and pneumonorrhaphy stapled and clamp tractotomy.^4,^7,¹⁹^–²⁵ In 1994, Wall et al.⁷ described clamp pulmonary tractotomy to maximize pulmonary parenchymal salvage. Asensio and colleagues in 1997¹⁹ described the technique of stapled pulmonary tractotomy. The applicability of stapled pulmonary tractotomy was subsequently confirmed as a safe, valuable, lung-sparing procedure in a series of 40 patients. Subsequently, Cothren and associates²² reported that lung-sparing techniques are associated with an improved morbidity and mortality compared with resectional techniques.

Rapid progress and advancement in technology, including endoscopic instrumentation anesthetic techniques, have revolutionized thoracic surgery and ushered in the era of video-assisted thoracoscopic surgery (VATS).²⁶ VATS has provided the trauma surgeon with an alternative method for accurate and direct evaluation of the lung parenchyma, mediastinum, and diaphragmatic injuries, with the advantage of simultaneously allowing definitive treatment of such injuries. VATS also has been demonstrated to be an accurate, safe, and reliable operative therapy for complications of lung trauma, including post-traumatic pleural collections.²⁷

INCIDENCE

The true incidence of pulmonary injuries is unknown, and difficult to estimate from the literature.²⁸^–³⁵ The chest, in forming such a large and exposed part of the body, is particularly vulnerable to injury. The anatomic complex formed by the lungs, pulmonary vessels, and bronchial tree so completely fills the thorax that penetration or contusion of the chest rarely occurs without injury.³⁶^–³⁸ The reported incidence of pulmonary injuries in the civilian arena varies according to authors and institutions. In 1979, Graham et al.³⁶ reported a 1-year experience, consisting of 373 patients sustaining penetrating pulmonary injuries; of these, 91 patients (24%) underwent thoracotomy, although operative interventions on the lung itself were only required in 45 (12%) patients. In this series, the mere presence of posttraumatic hemothorax or pneumothorax was considered by the authors as clear evidence of traumatic pulmonary injury, which justified the inclusion of these cases in the study.

In 1988, Robison et al.³⁹ described a 13-year civilian experience in the management of penetrating pulmonary injuries in 1168 patients sustaining penetrating chest injuries; however, only 68 patients required thoracotomy to manage traumatic lung injury. In 1988, Thompson et al.⁴⁰ reported a 5-year experience of 2608 patients with thoracic trauma. Of the total, 1663 patients sustained injuries from blunt trauma and only 11 (0.7%) required thoracotomy; 945 sustained penetrating injuries and 15 (1.6%) required thoracotomy. Wiencek and Wilson³⁵ reported a series consisting of 161 patients requiring thoracotomy for civilian penetrating pulmonary injuries during a 7-year period, which translates to 23 cases per year. Wagner et al.³⁷ described a 4-year experience of 104 patients with significant blunt chest trauma; 115 pulmonary lacerations were detected in 75 patients, for an incidence of 72%; 86% of these injuries were diagnosed by computed tomography (CT) scan, and 14% were detected by surgery. Based on both radiological and surgical findings, the authors reported a higher incidence of traumatic pulmonary injuries compared with other clinical series that report their results based only in surgical findings.

In 1993, Tominaga and colleagues ⁴¹ described a 7-year single institutional experience of 2934 patients sustaining both blunt and penetrating chest trauma; 347 patients (12%) required thoracotomy, and 12 (3.5%) in this subgroup required pulmonary resections. The mechanism of injury was blunt in 25%, and penetrating in 75% of cases, for an incidence of 0.04%, translating into 1.7 cases per year. Wagner and associates⁴² in 1996 described an 8-year experience of 1804 patients admitted with chest trauma; 269 (15%) underwent thoracotomy, with 55 requiring operative interventions specifically for their pulmonary injuries, for an incidence of 3%, and an average of 6.9 patients per year.

In 1997, Stewart et al.⁴³ reported a 10-year experience consisting of 2455 patients with both penetrating and blunt chest trauma; 183 (7.4%) patients required thoracotomy, and 32 (17.4%) required pulmonary resection, which translates to 3.2 cases per year. Inci and colleagues⁴⁴ in 1998 reported a 5-year experience consisting of 755 patients sustaining penetrating chest trauma, of whom 61 (8.1%) required thoracotomy; however, specific operative interventions for penetrating pulmonary injuries were required in only three patients (4.9%), for an incidence of 0.6 cases per year.

In 1998, Wall et al.⁴ described a 3-year experience of 236 patients requiring thoracotomy for penetrating chest trauma; 90 (38%) required repair or resection to manage their pulmonary lacerations, for an average of 30 patients per year. In 2001, Karmy-Jones and colleagues^21,⁴⁵ reported the findings of a multicenter 4-year review of five Level I trauma centers. A total of 43,119 patients were admitted for penetrating thoracic trauma, and 290 (2.8%) required thoracotomy; surprisingly, 115 patients (40%) in this subgroup underwent some type of lung resection. In a series of 4087 patients admitted for chest trauma, Cothren and associates²² reported that 416 patients (10%) patients required thoracotomy and 36 (9%) required surgical interventions on the lung, for an incidence of 1% and an average of 3.3 patients per year.

In the most recent report dealing with complex civilian lung injuries, in 2006, Asensio et al.⁴⁶ described 101 patients requiring thoracotomy for complex penetrating pulmonary injuries. In the military arena, Zakharia et al.⁴⁷ in 1985 reported 1992 casualties during the fighting in Lebanon; 1422 patients underwent thoracotomy for hemodynamic instability secondary to penetrating chest trauma, and pulmonary injuries were present in 210 (15%) patients, for an incidence of 11%. In 1997, Petricevic and associates ⁴⁸ reported on 2547 casualties from the most recent Balkan war experience. During a period of 4 years, 424 patients (16%) sustained both blunt and penetrating chest wounds; among these patients, 81 (19%) underwent thoracotomy for pulmonary injury, for an incidence of 20 cases per year.

ETIOLOGY

Most patients requiring thoracotomy for pulmonary injuries will have suffered penetrating mechanisms of injury—gunshot wounds, stab wounds, and shotgun wounds. Much less common are blunt thoracic injuries requiring operative intervention. In 2003, Huh et al.²⁴ reported a gradual rise in the incidence of blunt thoracic injuries, mostly from motor vehicle collisions requiring operative intervention, from 3% before 1994, to 12% in the latter period. In the series by Tominaga and colleagues,⁴¹ blunt mechanism of injury accounted for 25% of all pulmonary injuries requiring surgical treatment. In the civilian arena, gunshot wounds represent the major penetrating mechanism for patients requiring surgical treatment; several authors^4,^21,^22,^35–37,^39–41,⁴³^–⁴⁶ have reported that gunshot wounds account for 33%–80% of cases with penetrating pulmonary injuries, while stab wounds account for 17%–67% of these injuries. Karmy-Jones et al.,^21,⁴⁵ in a multicenter study on managing traumatic lung injuries, reported an increasing rate of thoracotomy among these patients. Other mechanisms such as impalement and shotgun wounds are reported with a lower frequency of 1%–5% of cases.^44,⁴⁶

In a series from 2006, Asensio et al.⁴⁶ reported on 101 patients who required thoracotomy for treatment of civilian penetrating pulmonary injuries. In this series, gunshot wounds accounted for most cases (72% of cases); stab wounds and other mechanisms (e.g., impalement, shotgun wounds) accounted for 33% and 5% of cases, respectively. In the military arena, Zakharia et al.⁴⁷ reported from the experience in Lebanon that high-velocity gunshot wounds and shelling in urban battles were the major mechanisms of pulmonary injuries. Petricevic and colleagues⁴⁸ reported the etiology of pulmonary injuries during the war in Croatia, where explosive wounds prevailed (59%), followed by gunshot wounds (both high and low velocity, 37%), whereas other types of wounds—stabbing and falling—accounted for only 4% of cases.

CLASSIFICATION

The American Association for the Surgery of Trauma Organ Injury Scaling Committee (AAST-OIS) described the lung injury scale in 1994.⁴⁹ This scale facilitates clinical research and provides a common nomenclature by which trauma surgeons may describe lung injuries and their severity. The grading scheme is fundamentally an anatomic description, scaled from 1 to 5, describing the least to the most severe injury. Thus far, studies have correlated injury grade with mortality for this study (Table 1).

Table 1 Lung Injury: Organ Injury Scaling, American Association for the Surgery of Trauma

Grade^a	Injury Type	Description^b
I	Contusion	Unilateral, <1 lobe
II	Contusion	Unilateral, single lobe
II	Laceration	Simple pneumothorax
III	Contusion	Unilateral, >1 lobe
	Laceration	Persistent (>72 hours), air leak from distal airway
	Hematoma	Nonexpanding intraparenchymal
IV	Laceration	Major (segmental or lobar) air leak
	Hematoma	Expanding intraparenchymal
	Vascular	Primary branch intrapulmonary vessel disruption
V	Vascular	Hilar vessel disruption
VI	Vascular	Total, uncontained transection of pulmonary hilum

a Advance one grade for multiple injuries up to grade III. Hemothorax is scored under thoracic vascular organ injury scale.

b Based on most accurate assessment at autopsy, operation, or radiological study.

DIAGNOSIS

The diagnosis of traumatic pulmonary injuries is established by physical examination and adjunctive diagnostic modalities.^37,^38,⁵⁰^–⁷⁴

Physical Examination

The clinical presentation of patients who sustain pulmonary injuries ranges from hemodynamic stability to cardiopulmonary arrest.⁵⁰ Physical examination yields a wealth of diagnostic information, which is used to indicate emergent interventions on these patients.⁵¹

Patients with pulmonary injuries may present with symptoms and signs of pneumohemothorax or an open pneumothorax with partial loss of the chest wall.^50,⁵² They may also present with a tension hemothorax or pneumothorax, or rarely, with a pneumomediastinum upon auscultation. Hamman’s crunch—a systolic crunch—may be detected upon auscultation in these patients. Similarly, they may also present with a pneumopericardium detected by auscultating Brichiteau’s windmill bruit (bruit de moulin). Patients with penetrating pulmonary injuries may rarely present with true hemoptysis. Occasionally, these patients present with symptoms and signs of an associated cardiac injury.^30,^31,^50,^65,⁶⁸

During the evaluation of these patients, the trauma surgeon must be cognizant that the thoracic cavity is composed of both right and left hemithoracic cavity as well as the anterior, posterior, and superior mediastinum; as often missiles or other wounding agents may traverse one or more of these cavities.^50,⁵³^–⁵⁷ Similarly, missile trajectories are often unpredictable and frequently create secondary missiles if they impact on hard bony structures (ribs, sternum, spine), thus creating the potential for associated injuries and greater damage.

Adjunctive Diagnostic Modalities

Adjunctive diagnostic modalities are divided into noninvasive diagnostic modalities and invasive diagnostic modalities.

Noninvasive Diagnostic Modalities

These diagnostic modalities include trauma ultrasound (focused assessment with sonography for trauma [FAST]), chest x-ray (CXR), CT, and electrocardiogram (EKG).

Trauma ultrasound

Trauma ultrasound is performed as part of the secondary survey of the trauma patient, and remains a valuable diagnostic modality used to detect associated cardiac injuries as well as the presence of associated abdominal injuries in patients sustaining isolated chest trauma and multiply injured patients.^58,⁵⁹ In 2004, Kirkpatrick et al.⁶⁰ reported the use of sonography for detecting traumatic pneumothoraces and described this diagnostic strategy as extended FAST (EFAST). Normal thoracic sonograms reveal comet-tail artifacts, originating from the sliding and reappositioning of the visceral onto the parietal pleura during the ventilatory effort; post-traumatic pneumothoraces are diagnosed when comet-tail artifacts are absent. The authors enrolled 225 patients in this study, and concluded that EFAST has comparable specificity (99.1% vs. 98.7%) to CXR, but was more sensitive (58.9% vs. 48.8%) for the detection of post-traumatic pneumothoraces. Knudson and colleagues⁶¹ in 2004 performed 328 thoracic evaluations in trauma patients and described thoracic sonography having a specificity of 99.7%, a negative predictive value of 99.7%, and an accuracy of 99.4% when used for diagnosing post-traumatic pneumothorax. However, thoracic sonography was noted to be more sensitive (100% vs. 88.9%) and with a higher positive-predictive value (100% vs. 88.9%) when used to diagnose post-traumatic pneumothoraces in patients sustaining penetrating versus blunt trauma, although the specificity (100% vs. 99.7%), negative-predictive value (100% vs. 99.7%), and accuracy (100% vs. 99.3%) are comparable. On the basis of these findings, Knudson et al.⁶¹ concluded that ultrasound is a reliable modality for the diagnosis of pneumothorax in the injured patient, and thus, it may serve as an adjunct or precursor to routine chest radiography in the evaluation of injured patients.

Sonography has also been employed to detect the presence of traumatic hemothorax. The technique for this examination is similar to evaluate the upper quadrants of the abdomen. The transducer is advanced to identify the hyperechoic diaphragm and to evaluate both right and left supradiaphragmatic spaces for the presence or absence of fluid. Sisley and associates ⁶² in 1998 evaluated 360 patients with suspected blunt or penetrating torso trauma, with 40 post-traumatic effusions, 39 (98%) of which were detected by sonography and 37 (93%) by CXR. The authors concluded that sonography is more sensitive (97.5 vs. 92.5%) than CXR for detecting post-traumatic effusions; however, a specificity of 97.5% in both studies is comparable. On the basis of these data the authors concluded that surgeon-performed thoracic sonography is as accurate as, but significantly faster than, supine portable chest radiography for the detection of traumatic effusion.

Chest X-Ray

A standard supine posteroanterior CXR is the most frequently used diagnostic modality in patients who sustain traumatic lung injury.^6,^10,^15,^23,^30,^31,^36–38,^44,^50,^52,^59,⁶³ Radiological diagnosis of traumatic pulmonary injuries by CXR is based on the presence of pneumothorax, pleural fluid collections, intrapulmonary hematomas, traumatic pneumatoceles, and pulmonary parenchymal contusions. Although CXR has been demonstrated to be 99% specific, it is a relatively insensitive test (49%) for the detection of post-traumatic pneumothorax; CXR has been demonstrated to possess a sensitivity of 93% and a specificity of 99.7% to detect post-traumatic pleural effusions.

When compared with CT, the conventional CXR underestimates or overlooks both parenchymal and pleural injuries, and has poor ability to determine the magnitude of pulmonary parenchymal compromise or pneumothorax size.^37,^38,⁶³ Wagner et al.³⁷ demonstrated that pulmonary parenchymal lacerations are frequently missed by CXR.

Computed tomography

Computed tomography is found to be more sensitive than CXR for diagnosing traumatic pulmonary injuries.^37,^38,⁶³ The most common types of abnormalities seen on CT scans include parenchymal lacerations, post-traumatic hemothorax, post-traumatic pneumothorax, atelectasis, subcutaneous emphysema, pneumopericardium and hemopericardium, and chest wall fractures. Additional diagnostic information related to the traumatic injury to the lung is usually supplied by CT scans, which can reliably detect the presence and extent of subtle or considerable parenchymal contusion.

As described by Karaaslan et al.³⁸ in 1995, CT scans are also able to detect the presence of associated thoracic and mediastinal vascular injuries, injuries to other thoracic great vessels, and extrathoracic injuries, associated cervical spine injuries, and intra-abdominal injuries in about 30% of cases.

Electrocardiogram

Nonspecific EKG abnormalities are often seen in trauma patients ⁶⁴^–⁷⁰; some of these changes such as sinus tachycardia, and ventricular and atrial extrasystoles are related to systemic factors such as pain, decreased intravascular volume, hypoxia, abnormal concentration of serum electrolytes, and changes in sympathetic or parasympathetic tone; however, in some cases, EKG may exhibit changes caused by associated injuries—most commonly penetrating or blunt cardiac trauma consisting of findings related to myocardial injury like new Q waves, ST-T segmental elevation or depression, conduction disorders such as right-bundle branch block, fascicular block, AV nodal conduction disorders, and other arrhythmias (atrial fibrillation, ventricular tachycardia, ventricular fibrillation, sinus bradycardia, and atrial tachycardia).⁶⁹^–⁷²

Electrocardiogram findings may suggest the presence of pericardial tamponade in patients sustaining chest trauma and traumatic lung injuries. Low QRS voltage is closely associated with the presence of a large or moderate pericardial tamponade (sensitivity of 0%–42%, specificity of 86%–97%),^69,⁷⁰ although PR segment depression and electrical alternans commonly are also present in this setting.^71,⁷²

Invasive Diagnostic Modalities

Chest tubes

Chest tube placement may be diagnostic as well as therapeutic.¹⁰ After entering the pleural cavity, a finger is inserted, and depending on the position of the tract, the trauma surgeon may palpate the lung surface for the presence of contusion, the surface of the diaphragm for lacerations, and the pericardial sac to detect the presence of tamponade.

The nature and amount of the material draining from the tube is also important. The amount of blood evacuated upon initial placement of the chest tube may indicate the need for thoracotomy; persistent drainage of blood through the tube thoracostomy obligates the trauma surgeon to reassess the need for surgical intervention.^56,⁵⁷ Drainage of gastrointestinal contents implies an esophageal,^54,⁵⁵ gastric, or intestinal injury⁵³ associated with a diaphragmatic laceration.⁷³ An air leak implies an underlying lung laceration, and large air leaks may indicate bronchial disruption.^10,^34,^35,^40,^52,^53,^56,^57,⁷⁴

ASSOCIATED INJURIES

Associated injuries are commonly seen in conjunction with penetrating pulmonary injuries.⁴⁶ Five to 65% of patients sustaining traumatic injuries to the lung present thoracic- or extrathoracic-associated injuries^20,^22,^24,^25,^35,^36,^39,^41,^43,^45,^46,⁴⁸; the average number of associated injuries reported in the literature ranges from 0.5 to 1.9 injuries per patient. The presence of an associated injury is an important determinant of outcome. Gasparri et al.²⁵ reported the presence of associated cardiac injury and the need for laparotomy for associated abdominal injuries as factors determining the mortality, while Asensio et al.⁴⁶ determined that the presence of an associated cardiac injury is an independent predictor of outcome.

Graham et al.³⁶ reported the presence of 73 associated thoracic injuries among 91 patients requiring thoracotomy for the management of penetrating pulmonary injuries, for an average of 0.8 associated thoracic injuries per patient; the most commonly injured organs included the heart, at 27%; intercostals, 16%; subclavian vessels, 9%; and superior vena cava, 7%. The authors also reported the presence of 175 associated abdominal injuries among 89 of the patients requiring laparotomy, for an average of 1.9 associated abdominal injuries per patient; the most frequently injured organs were the liver, 21%; spleen, 19%; stomach, 14%; and colon, 10%.

Robison and colleagues ³⁹ described the presence of 14 associated injuries in 11 of 28 patients sustaining traumatic lung injuries requiring thoracotomy and pulmonary resection or hilar repairs. In this series, the authors reported a morbidity rate of 39% and an average number of 1.3 injuries per patient. Cardiac injuries were present in 11% of cases; the remaining associated injuries follow: thoracic great vessel injuries, 7%; spinal cord injuries, 7%; hepatic injuries, 7%; pancreatic, 4%; colonic, 4%; spleen, 4%; gastric, 4%; and peripheral nerve, 4%.

Wiencek et al.³⁵ described the presence of 35 major associated injuries among 19 of 25 patients with central lung injuries, for an incidence of 76% and an average number of 1.4 injuries per patient, with the heart (26%) and thoracic great vessels (21%) as the most frequently injured organs. Associated abdominal injuries requiring laparotomy were found in 58% of cases. Tominaga and associates⁴¹ reported 10 associated injuries among 12 patients that required thoracotomy and lung resection for traumatic pulmonary injuries, for an average of 0.8 injuries per patient. Associated injuries included head injuries at 17%; intra-abdominal injuries requiring laparotomy, 33%; cardiac injuries, 25%; and great vessel injury, 8%. Petricevic et al.⁴⁸ reported a 4.5% incidence of associated injuries to visceral organs in patients sustaining chest trauma during the war in Croatia. Stewart and colleagues⁴³ described the presence of 30 associated injuries in 21 of 32 patients (65%) requiring thoracotomy and pulmonary resection for traumatic injuries to the lung, for an average of 1.4 injuries per patient; these injuries were stratified into abdominal, 30%; musculoskeletal, 30%; neurologic, 17%; cardiac, 7%; and other injuries, 17%.

Gasparri et al.²⁵ reported associated injuries in 41 (58%) of 70 patients requiring thoracotomy for penetrating lung injuries, with cardiac (20%), diaphragmatic (17%), and hepatic (11%) as the most common organs involved. Karmy-Jones and colleagues⁴⁵ reported 42 associated thoracic injuries among 115 patients requiring thoracotomy and lung resection for penetrating chest trauma, for an average of 0.36 injuries per patient.

Cothren et al.²² reported 27 associated injuries in a series of 36 patients requiring thoracotomy for severe pulmonary injuries, for an average of 0.75 injuries per patient. Associated thoracic injuries were present in 33% of patients, while associated extrathoracic injuries represented 66% of the total. Huh and colleagues²⁴ reported that 28% of patients requiring operative interventions on the lung required a concomitant laparotomy for intra-abdominal injuries.

Asensio and associates ⁴⁶ in 2006 reported a 169-month, single-center experience consisting of 101 patients requiring thoracotomy for penetrating pulmonary injuries. In this series, there were 193 associated injuries for an average of 1.9 injuries per patient. There were 39 (22%) associated injuries to the thoracic organs, and 154 (79.7%) associated extrathoracic injuries. The most common thoracic organs involved were the heart (23.7%) and thoracic great vessels (14.8%), while the most common extrathoracic organs were the diaphragm (42.5%), liver (25.7%), and stomach (18.8%).

ANATOMIC LOCATION OF INJURY

The anatomic location of pulmonary injuries is not commonly reported in either clinical or radiological series.^24,^35,^36,^39,⁴⁶ Graham et al.³⁶ reported a predominance of left-sided lung injuries at 52% compared with right-side lung injuries at 36%, with bilateral injuries present in 12% of patients. Wiencek et al.,³⁵ in a series focusing on central/hilar traumatic lung injuries, reported an incidence of 15% of hilar traumatic disruptions among 161 patients sustaining penetrating lung trauma. Robison and colleagues³⁹ described the anatomic location of traumatic lung injuries requiring resective techniques for surgical management as follows: left lower lobe, 28%; right middle lobe, 22%; left upper lobe, including lingula, 22%; right upper lobe, 17%; and right lower lobe, 17%. The left pulmonary artery (25%) was the most commonly injured pulmonary vessel, followed by the right pulmonary artery (14%), right pulmonary vein (11%), and left pulmonary vein (7%). The results of this series showed that traumatic injuries presented a slight right versus left preference, although left-sided vascular injuries were more common compared with right-sided pulmonary vascular injuries, at 56% and 44%, respectively.

Huh and associates ²⁴ reported that the location of the traumatic pulmonary injuries requiring operative intervention showed a slight predilection for the left side (50%), followed by the right side (47%) and bilateral injuries (3%). Asensio et al.,⁴⁶ in a report consisting of 101 patients requiring thoracotomy for complex penetrating pulmonary injuries, found the left lung to be a predominant location of penetrating injuries compared with the right lung (65% vs. 35%, respectively). The authors also reported the specific location of these injuries: left lower lobe, 40%; left upper lobe, 21%; right middle lobe, 19%; right lower lobe, 11%; lingula, 5%; and right upper lobe, 5%.

MANAGEMENT

Although recent reports of thoracic injuries in military actions have advocated early thoracotomy and aggressive management of pulmonary injuries with resection as opposed to the more conservative and traditional treatment with tube thoracostomy,^35,^39,^40,^44,^47,^48,^77–⁸¹ the vast majority of thoracic trauma patients—75%–85%—are successfully managed with placement of chest tubes and supportive measures.^4,^7,^10,^21,^22,^24,^36,^39,^41,^43,⁴⁵ The combination of lung expansion, low intravascular pressures, and high concentration of tissue thromboplastin provides adequate hemostasis in most instances²⁰; however, 9%–15% of patients require thoracotomy to achieve surgical hemostasis or effect necessary repairs.^35,^39,^40,^44,^47,^48,⁷⁷^–⁸¹ Of patients undergoing thoracotomy for hemorrhage, 3%–30% have been shown to require lung resection for control of injuries.^20,^21,^23,^24,^26,^32,^35,^36,^39–45,⁴⁸

The indications for thoracotomy in patients sustaining penetrating pulmonary injuries include the following ^35,^36,^39,^40,^44,^47,^48,⁷⁴^–⁸⁵:

Cardiopulmonary arrest ^39,^75,⁷⁶

Impeding cardiopulmonary arrest upon arrival at the emergency department (ED)^39,^75,⁷⁶

Evacuation of 1000–1500 ml of blood upon initial placement of chest tube ^33,^35,^36,^39,^47,⁴⁸

Evacuation of more than 1000 ml of blood upon placement of chest tube and ongoing blood loss ^33,^35,^36,^39,^47,⁴⁸

Tension hemothorax ^36,^39,^75,^76,⁷⁹^–⁸¹

Large retained hemothorax ^44,⁸²^–⁸⁵

Massive air leak from the chest tube ^36,^39,^40,⁷⁴

Surgical Decisions

For patients who present in cardiopulmonary arrest, it is mandatory to proceed to ED thoracotomy.^75,⁷⁶ The placement of a chest tube in the right hemithoracic cavity is required. This may need to be extended into bilateral anterolateral thoracotomies.^75,⁷⁶ For patients who present with systolic blood pressure lower than 80 mm Hg, it is mandatory to insert bilateral chest tubes and resuscitate per the Advanced Trauma Life Support protocol. If the patient remains unstable, he or she should be immediately transported to the operating room (OR). If the patient stabilizes, a thorough work-up should be instituted.^75,⁷⁶ For patients presenting with thoracoabdominal injuries, insertion of a chest tube or tubes is recommended. In patients who sustain abdominal and thoracic or thoracoabdominal injuries and require exploratory laparotomy, the trauma surgeon should reassess the need for thoracotomy in the OR.53–55,^66–68,⁷³^–⁷⁶