Blunt Traumatic Lung Injuries Daniel L

Home , Pulmonary contusion, Pulmonary hematoma

THORACIC SURGERY ELSEVIER CUNICS SAUNDERS Thorac Surg Clin 17 (2007) 57-61

Blunt Traumatic Lung Injuries Daniel L. Miller, MDa,*, Kamal A. Mansour, MDb

a Section of Genera/ Thoraeic Surgery. Deparlment of Surgery. Emory Universily and The Emory Clínic. 1365 C/iflon Road NE, AI/anla. GA 30322, USA bEmory University Schoo/ of Medicine, 1365 C/iflOn Road NE. AI/anla. GA 30322. USA

The first detailed description of chest trauma belt by reducing the chance that the occupant's appeared in the Edwin Smith Papyrus in ancient upper body will strike the vehicle's interior. Egypt circa 1600 BC [I]. In the fifth century BC, They aIso help reduce the risk of serious injury Hippocrates described hemoptysis after rib frac- by distributing crash forces more evenly across tures. He recognized that hemoptysis indicated in- the occupant's body. This decrease in lung injuries jury to the underlying lung, which was a more has been evident at Grady Memorial Hospital in severe injury than a simple rib fracture [2]. Ap- Atlanta, Georgia, one of the busiest level I trauma proximately one third of ali patients admitted to centers in the United States. From January I, major trauma centers in the United States sustain 200I through Oecember 31, 2006, a total of serious injuries to the chest. The lungs, which oc- 8780 patients were admitted to the Emory Univer- cupy a large portion of the chest cavity and lie in sity Trauma Service; 989 patients (lI %) had an close proximity to the bony thorax, are injured in associated lung injury related to their trauma. Pul- the majority of these patients directly or indi- monary contusions can also occur after falls from rectly. A significant number of lung injuries are great heights or from blast injuries. also associated with trauma to other critical tho- Isolated pulmonary contusions are encoun- racic structures. This article discusses blunt tered much less commonly than are contusions trauma injuries of the lung, which include pulmo- associated with other thoracic and nonthoracic nary contusions, hematomas, lacerations, and injuries. Because pulmonary contusions are so pulmonary vascular injuries. commonly associated with other injuries, the pathophysiology of the associated injuries, the resuscitative and therapeutic measures that are Pulmonary contusion necessary for their treatment, and the effects of Pulmonary contusion is the most common aspiration, infection, and adult respiratory dis- injury seen in association with thoracic trauma tress syndrome (AROS) on the lung parenchyma [3]. It occurs in 30% to 75% of patients sustaining have clouded the understanding of isolated pul- major chest injuries [4]. Pulmonary contusion is monary contusion. seen with blunt and penetrating wounds but is most common after motor vehicle accidents Pathology when the chest strikes the steering wheel or car door. The incidence of pulmonary contusions Wagner and colleagues [5]presented convincing may be decreasing because of supplementary re- evidence based on CT scan findings and limited straint systems, known as airbags, installed in pathologic material that a pulmonary laceration US automobiles. Air bags supplement the safety with resultant hemorrhage into adjacent alveolar spaces, rather than alveolar capillary wall injury, is the basis for the development of pulmonary con- * Corresponding author. tusions. They described four types of lacerations E-mail address:[email protected] that are associated with pulmonary contusions. (D.L. Miller). Type I lacerations are the result of compression

1547-4127{07{$ - see front matter @ 2007 Published by Elsevier Inc. doi: 10.1 016{j.thorsurg.2007 .03.017 thoracic.theclinics.com

94 ao 58 MILLER & MANSOUR of the elastic chest wall that causes the underlying development of atelectasis. If ventilation is in- air-filled lung to rupture. Type 11lacerations result adequate, intubation and mechanical ventilation from compression of the lower chest wall that are indicated. If large volumes of fluid are causes a sudden displacement of the lower lobe necessary for resuscitation, a pulmonary artery across the vertebral column and that produces catheter should be positioned so that pulmonary a shearing tear in the adjacent lung. Type 111lacer- artery pressures and pulmonary capillary wedge ations are small peripheral lacerations that are pressures can be measured. dose to rib fractures and are thought to be pene- The use of steroids and antibiotics is contro- trating injuries caused by the ends of the fractured versial. Some authorities advocate the use of high ribs. Type IV lacerations are tears caused by sud- doses of steroids for a short time, whereas others den chest wall compression that displaces the believe that the use of steroids is not indicated [8]. lung inwardly next to thick pleuropulmonary ad- Prophylactic antibiotics are used in some institu- hesions. Type I is the most commonly encountered tions; in others, antibiotics are used only when laceration and is almost always seen in patients evidence of infection is present. who are younger than 40 years of age. Type 111 Pulmonary contusions are not innocuous in- lacerations are the next most commonly seen and juries. In one series, 11% of patients with severe usually occur in older patients. isolated pulmonary contusions died, whereas the mortality rate was much higher (22%) in patients Diagnosis with associated injuries [9]. ARDS developed in 17% of patients with isolated pulmonary contu- Blunt trauma to the chest, falls, and blast sions and in 78% of patients with two or more si- injuries should ali suggest the possibility that multaneous associated injuries in other series [10]. a pulmonary contusion may occur. Dyspnea, tachypnea, hemoptysis, cyanosis, and hypotension are frequently seen. Physical examination may be Pulmonary lacerations unrevealing; however, in the presence of a severe contusion, inspiratory rales and decreased breath Pulmonary parenchymal lacerations, although sounds may be found. A chest radiograph shows seen more commonly after penetrating chest singular or multiple patchy alveolar infiltrates trauma, are also seen after blunt trauma. Al- caused by intra-alveolar hemorrhage [6]. These though blood vessels and tracheobronchial pas- patchy infiltrates can coalesce into homogenous sages may be disrupted, pneumothorax is in many infiltrates that involve a lobe or an entire lung. cases the major problem, and bleeding is of minor CT scans of the chest have been shown to be consequence. If the laceration involves the visceral more sensitive in demonstrating the changes seen pleura and the communication with the pleural with pulmonary contusions than are routine chest space remains patent, hemothorax, pneumotho- radiographs [5]. In patients with pulmonary con- rax, or hemopneumothorax results. If the visceral tusions, arterial Pa02, alveolar arterial oxygen pleura is tom but quickly seals, blood, air, or both gradients, and pulmonary compliance are usually can accumulate within the parenchyma and result abnormally low. Hyperventilation may induce hy- in the development of a hematoma, cyst, or a cyst pocapnia and respiratory alkalosis [7]. If the con- containing blood. tusion is massive or if aspiration, infection, or As a result of high-speed motor vehide ARDS develops, carbon dioxide may be retained crashes, extensive pulmonary lacerations, occa- and respiratory acidosis may ensue. sionally with volvulous or torsion of the lung, are being encountered with increasing frequency. Treatment Such lacerations often are centrally located, are associated with severe chest wall injuries and Patients with pulmonary contusions should be pulmonary contusion, and disrupt large vessels hospitalized for careful monitoring because they and major bronchi. can become critically ill rapidly. Oxygen should be administered as necessary to maintain arterial oxygen saturation greater than 90%. Patient- Pulmonary hematoma controlled analgesia, intravenous or epidural, should be used as necessary to control pain. Pulmonary lacerations resulting from blunt or Vigorous chest physiotherapy is important to penetrating injuries may fill with blood, forming keep the airway dear and help prevent the a pulmonary hematoma. The reported incidence

95 BLUNT TRAUMATIC LUNG INJURIES 59 of hematomas developing in pulmonary contu- has occurred, air is aspirated from the left side sions has ranged from 4% to Ii % [5,11]. Because of the heart, aorta, and coronary arteries. The hematomas are recognized infrequently in clinical vascular and bronchial injuries are then repaired, situations, the true incidence is likely to be less. if possible, and the laceration is left open and Despite an unimpressive radiographic appear- drained with appropriately placed chest tubes. ance, the injury represents a significant collection Torsion or volvulous of the lobe or lung of intraparenchymal blood. It may not become suggested by atypically oriented lobar collapse visible radiographically for 24 to 72 hours after also necessitates prompt diagnosis and operation. trauma resuscitation, during which time it in- At thoracotomy, the involved lobe or lung is creases insidiously. Pulmonary hematomas gener- untwisted and observed to ensure viability. If ally do not interfere with gas exchange, nor do there is any question about its viability, the lobe they produce significant intrapulmonary shunting. or lung should be resected. Otherwise, the in- Nevertheless, a pulmonary hematoma is a major volved lobe should be stapled, if possible, to an risk facto r for infection and lung abscess forrna- adjacent lobe to prevent retwisting. tion [12].The use of CT scans perrnits more accu- If a pulmonary hematoma or pulmonary rate evaluation of hematomas than conventional contusion is identified at the time of thoracotomy, radiographs. On CT scans, hematomas have the surgeon should resist the temptation to resect been found to shrink less than 0.5 cm in 3 weeks, the involved lung. Despite the gross appearance, whereas on conventional radiographs, they are re- there is rarely an indication for resection of an ported to resolve within 2 to 4 weeks of injury [5]. injured lung, unless there is associated significant In the absence of previous radiographs, serial injury to the airway or pulmonary vessels [16]. films, or serial CT scans demonstrating the evolu- tion of the hematoma, the exact nature of the nodule or lesion may be unclear, and the possibility of Pulmonary vascular injury a neoplasm must be considered. If the nodule re- Vascular injury within the pulmonary paren- mains stable after 4 weeks, showing no evidence chyma occurs within a low pressure system com- of resolution, fine-needle aspiration of the nodule pressed by the surrounding parenchyma. Such or surgical excision should be perforrned to estab- hemorrhage generally stops with complete expan- lish the nature of the lesion [13]. sion of the lung [16,17]; however, uncorrected injury to the main pulmonary arteries or veins or to Management their principie lobar branches is usually lethal from rapid exsanguination because these structures In most cases, pulmonary lacerations heal bleed freely into the pleural space. Major pulmo- promptly after chest tube insertion without any nary vascular injuries usually result from sudden significant long-Iasting ill effects. Peripherallacer- deceleration. Mortalities rates for pulmonary arte- ations encountered at operation can be oversewn rial or venous injuries exceed 75%; therefore, the (pneumonorrhaphy), stapled, or wedged out. majority of these patients rarely survive long Extensive lacerations may be centrally located enough to reach a trauma center. and may disrupt major vessels and bronchi. Re- sultant massive bleeding, large air leaks, and, Management although rarely seen, bronchopulmonary venous fistulas resulting in systemic air embolization If a major pulmonary vascular injury is di- require immediate operation. Proceeding to a tho- agnosed or suspected, control may be obtained at racotomy is deterrnined by the urgency of this the pulmonary hilum by clamping the entire situation, location of the injury, and structures hilum. Through a thoracotomy incision, the hilum presumed to be involved. Lately, more trauma of the lung is grasped firrnly with one hand as the centers are using thoracoscopy as a diagnostic or surgeon uses the other hand to apply a long therapeutic procedure for pulmonary lacerations vascular clamp across the entire pulmonary hilum. [14,15]; however, if a thoracotomy is required, hi- This maneuver excludes the main pulmonary lar compression with the fingers and then with artery and veins from the circulation, may prevent a large vascular clamp, such as a Satinsky or exsanguination, and provides time for the anes- curved DeBakey, is used to control bleeding and thesiologist to resuscitate the patient. If there is air leak and to stop systemic air embolization. a significant amount of blood in the airway, When the hilum is controlled, if embolization a double-Iumen endotracheal tube or a bronchial

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blocker may be used to protect the opposite lung United States. A comprehensive evaluation of from aspiration of blood. Next, the vascular these patients is needed to improve their survival. injury should be isolated and repaired using Understanding the lung injuries that can occur standard vascular techniques [18]. If a lobar pul- re1ated to blunt chest trauma is essential to monary artery is irreparable, it may be ligated improved outcomes. The use of VATS in blunt without fear of pulmonary necrosis. The bron- thoracic trauma has improved the diagnosis and chial blood supply is usually sufficient to maintain management of patients with life-threatening parenchymal viability. If the venous drainage to pulmonary injuries. a parenchymal region must be sacrificed, the involved parenchyma should be resected to prevent References infarction of that portion of the lung secondary to venous obstruction [18]. [I] Breasted JH. The Edwin Smith surgical papyrus, vol. 1. Chicago: University of Chicago Press; 1930. [2] Withington ET [translator]. Hippocrates, vol. 3. Video-assisted thoracic surgery or thoracoscopy Cambridge (MA): Harvard University Press; 1959. [99,307-13]. Although most chest traumas do not require [3] Wiot J. The radiographic manifestations of blunt a major operation, tube thoracostomy remains the chest trauma. JAMA 1975;231:500-3. basis of treatment. Patients who would have [4] Chopra P, Kroncke G, BerkoffH, et aI. Pulmonary contusion: a problem in blunt chest trauma. Wis required a thoracotomy in the past may actually Med J 1977;76:S1-3. benefit from a less invasive surgical technique to [5] Wagner RB, Crawford WO Jr, Schimpf PP. perform diagnostic and therapeutic procedures Classification of parenchymal injuries of the lung. after blunt chest trauma. Improvements in in- Radiology 1998;167:77-82. strumentation, especially endoscopic staplers and [6] Stevens E, Templeton A. Traumatic nonpenetrating cameras, and endoscopic surgical techniques have lung contusions. Radiology 1965;85:247-52. expanded the indications for video-assisted tho- [7] Erikson O, Shinozaki T, Beekman E, et aI. Relation- racic surgery (VATS) or thoracoscopy in the ship of arterial blood gases and pulmonary radio- diagnosis and treatment of diseases within the graphs to the degree of pulmonary contusion. chest; however, the use ofVATS remains contro- J Trauma 1971;11:689-94. [8] Svennevig J, Bugge-Asperheim B, Birkeland S, et aI. versial in trauma patients. Early publications Efficacy of steroids in the treatment of lung contu- explored the use of VATS in patients sustaining sion. Acta Chir Scand SuppI1980;499:87-92. thoracic trauma [19,20]. The results were encour- [9] Oemuth WE Jr, Smith JM. Pulmonary contusion. aging, but the series reported a small number of Am Surg 1965;109:819-23. cases. In 1999, a meta-analysis of the use of thor- [10] Pepe P, Potkin R, Reus O, et aI. Clinical predictors acoscopy in trauma was published that involved of the adult respiratory distress syndrome. Am J 28 studies and more than 500 patients. The com- Surg 1982;144:124-30. plication rate was 2% and the missed injury rate [li] Westermark N. A roentgenological investigation 0.8%. The most important benefit was that 62% into traumatic lung changes arisen through blast of patients did not require a thoracotomy or lap- violence to the thorax. Acta RadioI1941;22:331. arotomy for diagnosis or treatment of their tho- [12] HankinsJ, Attar S, Turndy S, et aI. Oifferential diagnosis of pulmonary parenchymal changes in thoracic racic injuries [21]. VATS is an accurate and trauma. Am Surg 1973;39:309-18. effective modality in the evaluation and manage- [13] Engelman RM, Boyd AO, Blum M, et aI. Multiple ment of hemodynamically stable patients who ex- circumscribed pulmonary hematomas masquerad- perience thoracic injuries. One should have a low ing as metastatic carcinoma. Ann Thorac Surg threshold to perform an open procedure if the sit- 1973;15:291--4. I uation arises. A reiative stable thoracic trauma [14] Abolhoda A, Livingston OH, Oonahoo JS, et aI. patient can become extremely unstable at any mo- Oiagnostic and therapeutic video assisted thoracic ment; therefore, one should be prepared to pro- surgery (VA TS) following chest trauma. Eur J Car- ceed with a thoracotomy immediately. Caution diothorac Surg 1997;12:356-60. should also be taken in the thoracic trauma [15] Manlulu A V, Lee TW, Thung KH, et aI. Current indications and results of VATS in the evaluation and l patient with multiple injuries, especially severe management of hemodynamically stable thoracic intra-abdominal injuries. injuries. Eur J Cardiothorac Surg 2004;25:1048-53. Blunt thoracic trauma continues to be a signif- [16] Graham JM, Mattox KL, Beall AC. Penetrating icant cause of morbidity and mortality in the trauma ofthe lung. J Trauma 1979;19:655-9.

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[17] Beall AC, Crawford HW, Debakey ME. Consid- treatment of thoracic injury. Am J Surg 1993;166: erations in the management of acute traumatic 690-5. hemothorax. J Thorac Cardiovasc Surg 1966;52: [20] Kern JA, Tribble CG, Spotnitz WD, et aI. Thor- 351-60. acoscopy in the subacute management of patients [18] Carr RE. Injuries to the pu1monary parenchyma and with thoracoabdominal trauma. Chest 1993;104: vasculature. In: Daughtry DC, editor. Thoracic 942-5. trauma. Boston: Little Brown; 1980. [21] Villavicencio RT, Aucar JA, Wall MR Jr. Analy- [19] Smith RS, Fry WR, Tsoi EKM, et aI. Preliminary re- sis of thoracoscopy in trauma. Surg Endosc 1999; port on videothoracoscopy in the evaluation and 13:3-9.