Chapter 23 Thoracic Injuries

1. Chapter 23 Thoracic Injuries

3. Introduction • Thoracic trauma accounts for a significant amount of injuries and fatalities annually • Approximately 700,000 emergency department visits • Over 18,000 deaths

4. You are dispatched to a call involving a gunshot victim. You are told he was trying to rob the liquor store and the clerk shot him with a .32-caliber handgun. • When you arrive, things are very quiet and still around the store. You see no obvious dangers, and the scene seems safe. However, police are still on the scene, two inside the store and two walking around the parking lot and front of the store. • Since you were dispatched to that scene, should you assume that it is safe to enter?

5. Anatomy (1 of 2) • Thorax: a bony cage consisting of the following structures: • 12 pairs of ribs • Scapula • Clavicle • Sternum • Thoracic vertebrae

6. Anatomy (2 of 2)

7. Sternum • Sternum: composed of three sections called the manubrium, body, and xyphoid process • Suprasternal notch: just superior to the manubrium • Angle of Louis: junction of the manubrium and sternal body

8. Rib Anatomy • Each of the 12 ribs attach posteriorly to the 12 vertebrae • Intercostal space: area located between the ribs • Neurovascular bundle: artery, vein, and nerve located in the intercostal space

9. Mediastinum • Located within the central region of the thorax • Contains heart, great vessels, esophagus, trachea, mainstem bronchi, and vagus and phrenic nerves

10. Pericardium • The heart is located within the pericardial sac. • The pericardial sac consists of two layers: visceral and parietal. • There is a potential for blood or fluid to become trapped between these layers.

11. Aorta • The largest artery in the human body • It exits the left ventricle, and attaches at three points: anulus, ligamentum arteriosum, and aortic hiatus. • These points represent sites of potential injury.

12. Lungs • Occupy most of the space in the thoracic cavity • Lined with two pleural membranes • Small amount of fluid found between parietal and visceral membranes

13. Respirations (1 of 2) • The diaphragm is the principle muscle of respiration. • Intercostal muscles work in conjunction with the diaphragm. • The thoracic cavity increases in size when the muscles contract.

14. Respirations (2 of 2)

15. Physiology • The process of breathing includes delivery of oxygen and removal of carbon dioxide. • Gas exchange occurs at alveoli.

16. Respiratory Stimulus • Stimulation to breathe occurs via chemoreceptors located in the carotid sinus and aortic arch. • When CO2 level increases, the brain is stimulated to increase respiratory rate and depth and “blow off” CO2.

17. Inspiration • The diaphragm contracts and moves downward while the intercostals contract and move outward. • Intrathoracic pressure decreases resulting in air entering the thoracic cavity.

18. Expiration • The diaphragm relaxes and moves upward while the chest wall relaxes. • Intrathoracic pressure increases above atmospheric pressure. • Air leaves the body.

19. Oxygenation and Ventilation • Oxygenation is the delivery of oxygen from the air to the blood. • Oxygen binds with hemoglobin. • Ventilation is the removal of carbon dioxide from the body to the atmosphere.

20. Cardiac Output • Proper cardiac output is required to ensure adequate tissue perfusion. • Cardiac output is the volume of blood delivered in one minute. • Cardiac output is equal to heart rate times stroke volume.

21. (continued) • When the scene is declared safe, you go in to find a man lying on the floor. He is bleeding heavily. Upon closer inspection, you can see that he has been shot twice—once in the upper chest, about an inch below his right clavicle, and once in the abdomen, slightly up and to the left of his belly button. • You note that the patient is pale; has cool, clammy skin; and is breathing rapidly but shallowly. The majority of the bleeding is coming from the wound in his abdomen. The one in his chest is bleeding only slightly. He tries to be combative and uncooperative, but he is weak and seems to be very confused. • When assessing the patient’s injuries, what possible (or probable) life-threatening problems are you facing? • How would you quickly and efficiently find out if any life-threatening conditions do exist for this patient?

22. Thoracic Injuries • Thoracic injuries risk serious airway, respiratory, and circulatory compromise for your patient. • Aggressive identification and management of injuries is required.

23. Flail Chest (1 of 2) • Major chest wall injury from blunt force trauma • Two or more adjacent ribs fractured in two or more places • Creates a “free-floating” segment that impairs chest wall motion

24. Flail Chest (2 of 2)

25. Rib Fractures • Most common thoracic injury • Patient often “self-splints,” leading to inadequate ventilation and atelectasis • Consider underlying injuries

26. Sternal Fractures • 1 out of 4 patients with this injury will die. • Patient will complain of anterior chest pain. • Look for deformity, flail sternum, and ECG changes.

27. Simple Pneumothorax (1 of 2) • Presentation depends upon size of pneumothorax. • Small pneumothorax may cause only mild dyspnea and pleuritic chest pain. • Breath sounds may be diminished.

28. Simple Pneumothorax (2 of 2) • Large pneumothorax will produce increased respiratory compromise: • Absent breath sounds • Hypoxia • AMS • Tachycardia • Cyanosis

29. Open Pneumothorax (1 of 2) • Occurs when a defect in the chest wall allows air to enter the thoracic space • Results from penetrating chest trauma • Air is drawn into the pleural space. • Collapse of lung results in mismatch between ventilation and perfusion.

30. Open Pneumothorax (2 of 2)

31. Tension Pneumothorax (1 of 3) • Life-threatening condition that results from continued air accumulation within the intrapleural space • May occur from open thoracic injury, blunt trauma, barotrauma, or shearing forces

32. Tension Pneumothorax (2 of 3) • Injury to the lung can cause a one-way valve to develop. • Air enters pleural space. • Air exerts increasing pressure.

33. Tension Pneumothorax (3 of 3) • Classic signs include: • Increased dyspnea • Absent breath sounds on affected side • Tachycardia • JVD (late sign) • Tracheal deviation (late sign)

34. Massive Hemothorax (1 of 2) • Occurs when blood begins to fill the potential space between the parietal and visceral pleura • Occurs in approximately 25% of chest trauma patients • Each lung can hold up to 3,000 mL of blood.

35. Massive Hemothorax (2 of 2) • Condition will result in both ventilatory compromise and circulatory collapse. • There are several physical findings that help differentiate between tension pneumothorax and hemothorax.

36. Pulmonary Contusion (1 of 2) • Caused by compression of lung tissue against chest wall • Alveolar and capillary damage results • Results in reduced delivery of oxygen across the alveolar-capillary membrane

37. Pulmonary Contusion (2 of 2) • Patient may have hemoptysis. • Look for signs of overlying injury, such as crepitus, tenderness, or contusions.

38. Pericardial Tamponade (1 of 3) • Excessive fluid in the pericardial sac causing compression of the heart • May be caused by blunt or penetrating injury

39. Pericardial Tamponade (2 of 3) • In medical conditions, inflammation leads to fluid collection. • As the pericardium fills, the atria and vena cavae become compressed. • Preload is therefore reduced, which reduces stroke volume.

40. Pericardial Tamponade (3 of 3) • Beck’s triad is a classic combination: • Muffled heart tones • Hypotension • JVD • Patient appears in shock with signs and symptoms similar to tension pneumothorax.

41. Myocardial Contusion (1 of 2) • Blunt cardiac injury caused by the heart colliding with the sternum • Leads to local tissue contusion, hemorrhage, edema, and cellular damage • May lead to dysrhythmias

42. Myocardial Contusion (2 of 2) • Patient complains of sharp, retrosternal chest pain. • Soft-tissue injury may be present. • Lung sounds may reveal crackles. • ECG changes may occur.

43. Myocardial Rupture • Acute perforation of the ventricles, atria, septum, chordae, muscles, or valves • Caused by severe blunt force compression • Life-threatening condition that accounts for 15% of fatal chest injuries

44. Commotio Cordis • Immediate cardiac arrest caused by blunt trauma during the heart’s repolarization period • Patient appears in ventricular fibrillation, which responds well to defibrillation if performed quickly.

45. Vascular Injuries (1 of 2) • Injury to the thoracic aorta accounts for one in every five blunt trauma deaths. • Caused by transection or dissection • Aorta is sheared at its fixed points. • Most patients die before EMS arrives.

46. Vascular Injuries (2 of 2) • Patient may complain of pain behind sternum. • Patient may also show signs and symptoms of hypoperfusion.

47. Diaphragmatic Injuries (1 of 2) • May be due to blunt or penetrating trauma • The most serious injury is diaphragmatic herniation. • Abdominal organs enter the thoracic cavity, causing a tension gastrothorax.

48. Diaphragmatic Injuries (2 of 2) • May be identified by bowel sounds in the chest cavity • Absence of breath sounds on affected side

49. Esophageal Injuries • Rapidly fatal injury • Associated with other significant injuries especially tracheal injuries • Patient may have subcutaneous emphysema. • There is no prehospital treatment.

50. Tracheobronchial Injuries • Rare injuries normally caused by penetrating trauma • Have a high mortality rate • May lead to a tension pneumothorax • Be prepared to decompress the patient as needed.