Thoracic Trauma

1. Thoracic Trauma Elaina Turner

2. List the types of thoracic trauma seen in small animals. • Trauma to thoracic cage • Open pneumothorax, fractures of ribs or sternum, flail chest, diaphragmatic hernia • Trauma to respiratory tract • Pulmonary contusion, laceration, traumatic bullae, ruptured trachea • Trauma to cardiovascular system • Myocardial contusion, hemothroax, ruptured aorta • Pleural space disease • Pneumothorax, pneumomediastinum, flail chest, hemothorax, traumatic chylothorax

3. Now cross-index or chart these types of trauma vs. etiology. • Blunt or penetrating trauma • Blunt • Pulmonary contusion • Pulmonic bullae • Pneumothorax, pneumomediastinum, hemothorax • Myocardial contusion • Trauma to thoracic cage (diaphragmatic hernia, fractured rib or sternum, flail chest) • Rupture of trachea (cat), aorta (horse) • Penetrating • Pulmonary laceration • Open pneumothorax • Hemothorax • Diaphragmatic hernia

4. Which of these conditions causes primarily respiratory embarrassment, and which causes primarily circulatory embarrassment?

5. What is the incidence of thoracic trauma in hit-by-car dogs? • 12% of all HBCs have some type of thoracic trauma

6. What is the incidence of thoracic trauma in hit-by-car dogs that have also sustained fractures? • 38.9% of all HBCs with fractures have some type of thoracic trauma

7. Which are the most common types of trauma seen in hit-by-car dogs with fractures? • Pulmonary contusion • Pneumothorax • Fracture of rib or sternum • Hemothorax • Diaphragmatic hernia

8. Why is it important to you as a surgeon to detect pulmonary contusion? • May have to delay anesthesia and surgery for repair of other injuries (fractures)

9. List or chart the different types of pneumothorax vs. etiology, signalment, source or air, and integrity of chest wall. Bite & stab wounds, gunshot, impalement, inadequate thoracotomy closure No hx of trauma, chronic obstructive lung disease Blunt trauma, fractured rib, ruptured pseudocyst More common in med to lg dogs, occurs in small and cats - BLEB Cutaneous Pulmonary (trachea, bronchi, lungs) Esophageal Pulmonary (lungs)

10. Which is the most common type? • Open pneumothorax??????????

11. Which type is not traumatic in origin? • Spontaneous pneumothorax

12. Which type has the best prognosis? • Closed???????????

13. How do both pulmonary contusion and pneumothorax result in ventilation-perfusion mismatch? • Pneumothorax – increased physiologic dead space and pulmonary shunting • Contusion – increased physiologic dead space due to too much blood, thus air can not enter the alveoli

14. Why do these pateints develop respiratory acidosis, despite tachypnea? • They are not ventilating anything other than their dead space

15. What specific tx is required for the patient with severe closed pneumothorax, before oxygen supplementation is of greatest possible benefit? • Tube thoracostomy with continuous suction drainage or Heimlich valve

16. What is the emergency tx for a dog with an open pneumothorax? • Cover wound w/ sterile non-occlusive dressing • Insert thoracostomy tube • Repair definitvely or place sterile occlusive dressing over wound until closure • If penetrating object is present in chest wall, do not pull it out • Radiograph chest to determine intrathoracic location of object • Thoracotomy in location that will allow removal of object under direct visualization

17. What is the course of tx for a dog that has impaled itself and is presented with a stick protruding from the thoracic wall? • See previous slide….

18. Hemothorax, like pneumothorax, is a pleural space disease, T or F? • True

19. Why are the CS seen in dogs and cats with hemothorax (and no other pleural space dz) not referable to the respiratory system? • Pulmonary circulation is low pressure – volume of hemorrhage usually too low to cause severe hydrothorax • Patients show signs of circulatory insufficiency rather than signs of respiratory insufficiency

20. What is the tx for hemothorax? • Mild case • Rest and observation • Moderate or severe case • Tx for shock • Restore oxygen-carrying capacity w/ whole blood or oxyglobin (autotransfusion) • Monitor patient carefully – if shock recurs, exploratory thoracotomy indicated (rare)

21. Why do animals with fractured ribs become hypoxic? • Pain increased by deep inhalation • Animal voluntarily restricts respiratory effort • Increased hypoxia

22. What can you do to alleviate this condition? • Use intercostal nerve blocks

23. Much of the dyspnea seen in patients with fractured ribs and flail chests is a result of another traumatic condition. • Go to next slide…………..

24. What is that condition? • Contusions and lacerations

25. What is the recommended tx for a simple flail chest? • Stabilize with an external splint

26. Describe the signalment and clinical signs of a patient with traumatic myocarditis. • Medium and large dogs, especially dogs w/ deep chests • CS: • Weakness and depression • Cardiac arrhythmia • Pulse deficit • Dyspnea and cyanosis

27. What is the significance of this condition to you as a surgeon? • Causes significant anesthetic risk • Decreased CO • Cardiogenic shock • Potential for fatal arrhythmias • Fatal arrhythmias may occur w/o anesthesia

28. When is chest wall reconstruction indicated? • Following en bloc resection of 3 or more consecutive ribs • Neoplasia • Trauma • Infection

29. Which methods of reconstruction bring additional vascular supply to the area of defect? • Omental and muscle pedicle flaps

30. Which provide mechanical support to the chest wall? • Polypropylene mesh • Lubra plates secured to ribs • Muscle flap – some