Thoracic trauma Richard Wills,MD,MBA,ACSM, Michael Norton,DC, and Kathryn DeLaney Approximately 25% of nonmilitary trau- ma-related deaths are due to thoracic trau- ma.1 The majority of deaths occur after the patient reaches the .Death will occur in about one third of the patients in which two or more organ systems are involved.Penetration and blunt force are the two mechanisms that cause thoracic trauma.Normal thoracic anatomy is shown in Figures 1 and 2.Penetrating thoracic trauma will cause in nearly all cases,with seen in more than 75% of these cases.One third of the cases of will be associ- ated with abdominal .Blunt trau- ma may be due to:compression (organ rup- ture), direct trauma (fracture), or acceleration/deceleration forces (vessel shear and tear).1 This article discusses several major types of traumatic thoracic injuries.

FEBRUARY 2001 The Surgical Technologist 21 197 FEBRUARY 2001 CATEGORY 3

eneral considerations describes traumatic injuries to the Patients sustain blunt thoracic trauma and according to their location. develop acute respiratory distress have a very high morality rate.2 (Table 1) Of the patients that experience with respiratory distress, three Subcutaneous emphysema is produced by pene- fourths will die.1 trating or blunt injuries, generally to the Patients that are diagnosed with respiratory and parietal pleura, causing air to be forced into distress will need airway control, optimal oxy- the tissues of the chest wall. The patient may dis- genation, and possibly ventilatory support and play an initial pneumothorax; however, massive . At the time of hospital admission, development of subcutaneous emphysema can 10% of these patients will require endotracheal delay the onset of pneumothorax. Generally, intubation. Most likely, the respiratory problem there is seldom reason to treat the subcutaneous is due to head trauma and/or spinal cord . emphysema; however,a cervical incision is useful Additionally, upper airway obstruction should to allow trapped air to escape. Attention should be suspected if the patient is attempting to be directed toward confirming the source of air breathe with little or no air movement. Upper leakage, which may be due to an esophageal per- gairway obstruction is common in comatose foration or major bronchial injury. Once the patients due to prolapse of the tongue into the source of air leakage is determined, immediate pharynx. Other causes of upper airway obstruc- treatment to solve the cause of the subcutaneous tion include vomitus or blood clots within the emphysema is implemented. pharynx, , or upper . If laryngeal trauma is suspected, an Mediastinal emphysema endoscopy should be performed as soon as pos- Mediastinal emphysema occurs when air enters sible. Emergency may become nec- the areolar tissue from a tracheal or bronchial essary to treat total airway occlusion from any wound, or from a perforation of the esophagus. cause. Once the upper airway is determined to be Blunt injuries to the chest may disrupt the bron- intact and breath sounds remain poor, thoracic chioles and alveolar units without disrupting the trauma should be suspected. , hemoth- visceral pleura. Air moves into the pulmonary orax, pneumothorax, , interstitium, centrally along the pulmonary and diaphragmatic injury, or parenchymal bronchial vessels until it reaches the medi- damage should be considered. Table two astinum. If the mediastinal pleura stays intact,

Table 1: Patients with following blunt thoracic trauma1

Type of Injury Incidence % Mortality Rate % Flail chest/multiple fracture 75 52 Hemopneumothorax 55 39 Lung contusion 39 45 Extremity fracture 30 53 Intraabdominal 23 46 Intracranial 23 46 Myocardial contusion 13 57 Diaphragm 9 20 Paraplegia 4 100 Other 7 100

22 The Surgical Technologist FEBRUARY 2001 air dissects into the neck tissue, moving through traction (by encircling the fractured with the deep tissue planes and finally spreading into towel clips or wire), and . the subcutaneous tissue. Improvements in respiratory therapy and the increased availability of arterial blood-gas stud- Flail chest ies have improved the outcomes for patients Flail chest is a crushing that implies with flail chest injuries.2 Mild to moderate flail disruption of the mechanism of , chest injuries can often be managed without a resulting in paradoxical motion of the chest wall by: region. For flail chest to occur, at least two seg- • Relief of pain (intercostal or mental fractures of three adjacent ribs or costal ) must occur (Figure 3). Combinations • Physiotherapy of the chest of rib and sternal fractures accompanied by cos- • Restriction of IV fluids to prevent volume tochondral or chondrosternal separations result overload.1 in paradoxical respiratory motion which is char- Ventilatory support may be implemented if 2 acteristic of a flail chest. There are three types the patient’s arterial P02 falls below 80 mm Hg of flail chest: lateral, anterior, and posterior. Flail chest injury may also be accompanied by pul- FIGURE 1 monary contusion, myocardial injury, pneu- mothorax, and hemothorax. Myocardial contusion must be considered, especially with anterior chest wall traumas. A trachea serial electrocardiogram, cardiac isoenzyme mediastinal space study, and radioisotope delineation of injured Visceral pleura myocardium may be appropriate for correlation left lung with clinical evidence of cardiac failure or peri- parietal pleura cardial friction rubs. pericardial sac While the posterior flail chest is rare, it is the diaphragm easiest to manage due to strong muscular and rib scapular support in the region and the patient’s secondary bronchi tendency to lie on his or her back. Respiratory right primary distress with and intrapulmonary shunt, as seen in flail chest injuries, is often due to rather than the para- while on supplemental .Ventilatory sup- doxical motion of the overlying chest wall. The port is necessary if: the patient is in shock; suffers paradoxical motion of the chest wall injury may from three or more associated injuries; has severe become apparent only after the associated lung head trauma, preexisting pulmonary disease, or injury has produced a sharp reduction in pul- fracture of eight or more ribs; or is 65 years old monary compliance and a severe increase in res- or older.1 Early ventilatory support in patients piratory effort. Pneumothorax is often present in with flail chest trauma can reduce mortality by severe flail chest injuries, and in these patients, about 7%. Patients not given immediate ventila- placement of an intercostal may relieve tory support have a mortality rate of 65% or the respiratory distress. greater. Early diagnosis and prompt medical The two main concepts for treatment of flail management can greatly reduce mortality. chest are chest-wall stabilization and reduction of intrathoracic dead space. Treatment options Pulmonary contusion for stabilizing a flail chest include the use of an Pulmonary contusion is defined as direct dam- external compression dressing, application of age to the lung resulting in both hemorrhage and

FEBRUARY 2001 The Surgical Technologist 23 in the absence of a pulmonary laceration. and blood out of the and into the It has a very high morbidity and mortality rate interstitium and alveoli. During this process, the following penetrating and . Mod- congestion and contusion continue to the next ern diagnostic techniques, such as the CT scan, uninjured segment of the lung. Changes within have made recognition of this common problem the capillaries leads to extravasation of red blood much more frequent. Opacification seen on X- cells and the accumulation of edema fluid with- ray within six hours of trauma generally is con- in the interstitium. These processes do not occur sidered to be a pulmonary contusion. simultaneously, but rather in a sequence. The The most common cause of this type of trau- main problem is intra-alveolar hemorrhage and ma is a compression/decompression injury to edema followed by a course of fluid resuscita- the chest, such as may occur during a high-speed tion. The hemorrhage and edema, together with automobile crash. Airbags can lessen but do not an accumulation of debris and mucous secre- entirely prevent this type of injury. A compres- tions, cause pulmonary to occur, lead- sion/decompression injury occurs when a high- ing to large areas of unventilated but still per- pressure wave within the thoracic cavity is fused lung. Intrapulmonary shunting is FIGURE 2 increased, as is the resistance to airflow, causing an increase in respiratory effort to move oxygen Muscles of the chest wall into and out of the lungs. Pul- monary ventilation is decreased, and the patient platysma muscle becomes hypoxic, hypercarbic, and acidotic.As a sternocleidomastoid muscle result, the will try to adapt to an increase subclavius in , but because of the , cardiopulmonary decompensation will occur pectoralis minor quickly. intercostal muscle Treatment of pulmonary contusion generally serratus anterior involves maintenance of adequate ventilation of deltoid muscle the lungs. , intercostal nerve blocks, epidural analgesia, and nasotracheal suc- tion are necessary to ensure the patient is ade- quately oxygenated.

Hemothorax caused by rapid compression.As the wave moves Hemothorax is most frequently caused by bleed- through the chest wall, the pressure wave reaches ing from lung injuries. Only 5 to 15% of patients the lungs, causing an instant increase in with hemothorax require , due to intrathoracic pressure followed by an instant the fact that the in the chest, along with drop (decompression).2 a high concentration of thromboplastin in the Pulmonary contusion has two stages: the first lungs and low pulmonary arterial pressure, is related to the initial injury; the second to reduces the chance of surgery.2 A volume of resuscitative measures and massive fluid over- more than 300-500 ml of blood in the chest cav- load. Administration of fluids to patients with ity must be removed completely as soon as possi- unilateral pulmonary contusion can cause ble. In the chest, large clots act as local anticoag- extravasation of fluid to the contralateral (unin- ulant by releasing fibrinolysins and jured) lung. A reduction in the pulmonary vas- fibrogenolysins from their surface. A large cular resistance of the uninjured lung causes the amount of blood in the chest can also restrict right side of the heart to increase hydrostatic ventilation and venous return. Bleeding from pressure within the capillaries to force both fluid multiple small intrathoracic vessels will often

24 The Surgical Technologist FEBRUARY 2001 Table 2:Types of thoracic trauma

1. Trauma to the outer region of the chest 3. Trauma to the innermost region of the chest A. subcutaneous emphysema A. mediastinal emphysema B. paradoxical respiration(flail chest) B. C. open pneumothorax C. compression atelectasis (trauma to the diaphragm) 2. Trauma to the inner region of the chest A. closed pneumothorax B. hemothorax C. secretional obstruction of the lower air- ways (as in pulmonary contusion,“wet lung,”and aspiration pneumonitis)

stop fairly rapidly after the volume of blood is FIGURE 3 completely removed. Hemothorax should be suspected following Flail chest detail trauma if: breath sounds are reduced; the chest is dull to percussion on the involved side; or fluid rib 3—two fractures collections greater than 300 ml are seen on rib 4—two fractures upright or decubitus roentgenograms of the rib 5—two fractures chest. Treatment depends on the size of the rib 6—two fractures hemothorax. Large hemothoraxes should be treated by insertion of a (tube thora- costomy). Blood that collects within the causes a reduction in the vital capacity of the lung and an increase in intrathoracic pressure,thereby decreasing minute ventilation and venous return to the heart. During inspiration, the negative intrapleural pressure increases the tendency for FIGURE 4 blood and air to leak into the pleural cavity through the wound in the lung or chest wall. The Pneumothorax patient with an upper airway obstruction has additional air forced into the pleural space during pleaural edge expiration, increasing the possibility of a tension at midline pneumothorax because the intrapleural pressure hemidiaphragms at equal heights exceeds atmospheric pressure.

Pneumothorax Pneumothorax is the presence of air in the pleur- al space (Figure 4). Chest X-ray upon admission to the emergency department is the ideal diag- nostic tool. However, a clinical diagnosis can be made based on the following criteria:

FEBRUARY 2001 The Surgical Technologist 25 • Severe respiratory distress The patient with a small may • Distended neck veins experience a delayed pneumothorax that can • Decreased breath sounds and hyperreso- occur 12 or more hours following the trauma. nance unilaterally Serial chest X-rays every six hours for 12 to 24 • Deviation of the trachea away from the hours are generally indicated in these patients. affected side.2 Following observation and repeated chest X- rays, the patient may be discharged if no other When pneumothorax is suspected, but not seen problems are noted. clearly on the first chest X-ray, an expiratory When pneumothorax is assumed, treatment film may be helpful. The patient may not show should be started without waiting for a chest X- severe symptoms of pneumothorax unless: it ray. Treatment of pneumothorax consists of occurs in patients with shock or preexisting car- placement of a large needle into the involved diopulmonary disease; it is a tension pneu- pleural space through a midclavicular or second mothorax; or it occupies more than 40% of the intercostal space puncture and aspirating any hemothorax.2 air. This procedure can also confirm the diagno- sis of the pneumothorax and may provide tem- FIGURE 5 porary relief until a tube thoracostomy can be performed. If a pneumothorax persists in spite Emergency of one or more well-placed chest tubes, an emer- gency bronchoscopy should be performed to pericardiocentesis clear the bronchi and identify any damage to the tracheobronchial tree that may need repair. Con- tinued air leakage and failure of the lung to heart expand adequately is an indication for early tho- blood racotomy.2 Trauma to the diaphragm The most common cause of a diaphragmatic injury is penetrating trauma,particularly gunshot wounds to the lower chest or upper . Diaphragmatic injury due to blunt trauma is less frequent, only occurring in 4 to 5% of patients with diaphragmatic injury. If a is pre- sent,the incidence of diaphragmatic injury due to blunt trauma increases to 8 to 10%.2 Rupture of the diaphragm can cause serious ventilatory problems, but the initial are generally masked by other injuries. If the diaphragmatic injury is large, the intestinal viscera enters the chest cavity immedi- ately. On the other , if the diaphragmatic defect is small, the intestinal viscera may take time to move into the chest cavity, eventually becoming obstructed or strangulated, leading to the formation of a tension pneumothorax. Generally, patients suffering penetrating diaphragmatic injury are diagnosed according to

26 The Surgical Technologist FEBRUARY 2001 the location of an entrance wound or intraoper- Conclusion atively. Fifty percent of diaphragmatic injuries Rapid diagnosis and immediate treatment are are diagnosed surgically (via thoracotomy or necessary when chest trauma is suspected. Mod- laparotomy). Patients suffering blunt trauma ern radiographic techniques, blood laboratory may show an abnormality of the lower lung studies, and give the patient care fields or diaphragm on chest X-ray.Additionally, team valuable diagnostic treatment shortly after diaphragmatic injuries may be diagnosed using admission to the emergency department allow- the following methods. ing treatment to be implemented within min- utes, lowering the mortality rate. 1. Peritoneal lavage with a chest tube in place 2. Upper GI series About the Authors 3. Pneumoperitoneum with carbon dioxide Richard E Wills, MD, MBA, ACSM is the medical 4. CT scan with contrast director and program director of Steven’s 5. Intraperitoneal technetium sulfur colloid.2 Henager Physician Assistant Program and pro- fessor of clinical medicine. Michael Norton, DC, Optimal repair of a diaphragmatic injury occurs is the owner of Chiropractic Health and Fitness during laparotomy. and adjunct professor of medicine at Steven’s Henager College in Salt Lake City, Utah. Kathryn Cardiac tamponade DeLaney is an EMT and medical assistant in Salt Cardiac tamponade may be caused by penetrat- Lake City, Utah. ing or blunt trauma to the chest, due to an accu- mulation of blood within the pericardial sac. References The most common penetrating cause of cardiac 1. Tintinalli JE. . New York: tamponade is a stab wound to the mid-chest; McGraw-Hill; 2000. while blunt compressive forces to the anterior 2. Schwartz SI. Principles of Surgery, 4th ed. New heart cause rupture of the right atrium. Due to York: McGraw-Hill; 1984 the injury, blood fills the pericardial sac causing 3. Active First Aid Online—Chest Injuries pressure within the sac to rise rapidly. During www.parasolemt.com.au Accessed 1-9-01 this time, the right ventricle may be able to main- 4. Medic Boss—Chest and Abdominal Injuries tain enough blood volume to sustain life for a www.cyberramp.net/~johnholt/chest%20and%20abd short interval. The patient will show the same ominal%20injuries Accessed 1-9-01 symptoms as seen with a tension pneumothorax. 5. Trauma.org—Thoracic Trauma Both cardiac tamponade and tension pneu- www.trauma.org /thoracic/index.html Accessed 1-9-01 mothorax will cause obstruction of venous 6. Virtual Hospital—Chest Trauma www.vh.org/ return to the heart. Patients will have hypoperfu- Providers/TeachingFiles/M3M4TeachingModules/Mullan sion, and distended neck veins. As the tampon- /ChestTrauma.html Accessed 1-9-01 ade progresses, the heart sounds will also be muffled and become more distant as the pericar- dial pressure increases.2 The initial treatment is emergency pericar- diocentesis (Figure 5), followed by surgical inter- vention, if necessary, to control bleeding. The patient should be given an intravenous bolus of Figures 3 and 4 used with permission of Virtual Hospital, fluid to fill the right atrium and increase cardiac www.vh.org. Figure 5 from Surgical Technology for the Sur- output. Aspiration of 5 to 10 ml of blood can gical Technologist: A Positive Care Approach, 1st edition, by substantially improve cardiac performance and Wintermantel C2001. Reprinted with permission of Del- outcome. mar, a division of Thompson Learning. Fax 800-730-2215.

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CECONTINUINGExam EDUCATION EXAMINATION

6. Emergency pericardiocentesis is used to treat ____. 1. Pneumothorax is defined as ____. A. cardiac tamponade A. blood within the pleural space B. pneumothorax B. air within the pleural space C. trauma to the diaphragm C. chyle within the pleural space D. None of the above D. pus within the pleural space 7. What is the most common cause of 2. Under normal circumstances,lung diaphragmatic trauma? Thoracic trauma expansion in maintained by A. blunt trauma A. positive pressure within the pleural cavity B. penetrating trauma B. negative pressure within the pleural cavity C. tension pneumothorax Earn CE credit at home C. positive pressure mechanical ventilation D. increased intrathoracic pressure You will be awarded one continuing education (CE) credit for D. atmospheric pressure within the pleural cavity recertification after reading the designated article and complet- 8. Which of the following is the best approach ing the exam with a score of 70% or better. 3. Following pneumothorax,lung expansion is to treating a diaphragmatic injury? If you are a current AST member and are certified, credit maintained with the use of ____. A. tube thoracostomy A. positive pressure mechanical ventilation B. median sternotomy earned through completion of the CE exam will automatically B. tracheotomy C. thoracotomy be recorded in your file—you do not have to submit a CE report- C. thoracotomy D. laparotomy ing form. A printout of all the CE credits you have earned, includ- D. tube thoracostomy ing Journal CE credits, will be mailed to you in the first quarter 9. Cardiac tamponade is described as ____. following the end of the calendar year. You may check the status 4. Treatment options for flail chest include A. blood contained within the pleural space of your CE record with AST at any time. ____. B. air contained within the pericardial sac A. mechanical ventilation C. blood contained within the pericardial sac If you are not an AST member or not certified, you will be B. stabilization D. massive fluid overload notified by mail when Journal credits are submitted, but your C. pain control credits will not be recorded in AST’s files. D. all of the above 10. Cardial tamponade may be difficult to Detach or photocopy the answer block, include your check or diagnose because the patient will show the money order made payable to AST and send it to the Accounting 5. The term opacification refers to ____. same symptoms as ____. Department, AST, 6 West Dry Creek Circle, Suite 200, Littleton, CO A. application of a sequential compression device A. pneumothorax 80120-8031. B. a large hemothorax B. tension pneumothorax C. the development of a white spot on a X-ray C. diaphragmatic trauma Members: $6 per CE, nonmembers: $10 per CE D. spasm of the heart D. subcutaneous emphysema

197 FEBRUARY 2001 CATEGORY 3

Thoracic trauma abcd abcd

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Certification No ______2 ❑❑❑❑ 7 ❑❑❑❑

Name ______3 ❑❑❑❑ 8 ❑❑❑❑

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City______State ______ZIP ______5 ❑❑❑❑ 10 ❑❑❑❑

Telephone ______Mark one box next to each number. Only one correct or best answer can be selected for each question.