Thoracic Trauma

Question 1

What are the 2 most common results of thoracic trauma?

Answer 1

1. PNEUMOTHORAX - increased intrathoracic pressure against a closed glottis resulting in alveolar rupture and accumulation of air in the plerual space –> hypoventilation, hypoxemia, vena cava collapse
2. PULMONARY CONTUSIONS - compression of thoracic wall and lungs causes elastic recoil and shearing forces on the blood vessels / hemorrhage into alveoli and pulmonary interstitium –> ventilation/perfusion mismatch, hypoxemia

Question 2

Why can diaphragmatic hernias occur with thoracic trauma?

Answer 2

• abdominal trauma causes increased pressure directed and transmitted across the diaphragm
• an open glottis results in low intra-pleural pressure, which creates a large peritoneal-pleural pressure gradient
• this results in the diaphragm rupturing at its weakest point

Question 3

What is the most common viscera to be found within a diaphragmatic hernia? What else is seen?

Answer 3

liver

• spleen
• small intestine
• stomach
• greater omentum

Question 4

What is the most concerning contents of a diaphragmatic hernia?

Answer 4

stomach –> severe distention

Question 5

What results following a diaphragmatic hernia?

Answer 5

decreased lung capacity = hypoventilation, ventilation/perfusion mismatch, hypoxemia

Question 6

What is a flail segment? What does it result in?

Answer 6

ribs fractured in two places results in independent movement of the segment

hypoxia secondary to pulmonary contusions from impact and hypoventilation from pain

Question 7

What clinical signs are seen in cases of pneumothorax, pulmonary contusions, diaphragmatic hernias, and rib fractures/flail segments?

Answer 7

dyspnea, tachypnea, muffled or diminished lung sounds especially dorsally

dyspnea, tachypnea, increased lung sounds/crackles, may not be apparent initial (up to 24 hours)

respiratory distress, rapid and shallow breathing (worse when patient is laying down), muffled lung sounds (especially unilateral), borborygmi

rapid/shallow breathing pattern, pain on palpation of chest wall, paradoxical movement of chest wall

Question 8

What are 3 parts to diagnosing thoracic trauma?

Answer 8

1. thoracic radiographs - only when stable!
2. thoracocentesis - for pneumothorax!
3. arterial blood gas - hypoxemia, hyper/hypocapnea

Question 9

What are 4 specific signs of thoracic trauma on radiographs?

Answer 9

1. pneumothorax - retraction of lungs from the chest wall and sternal elevation of the heart
2. pulmonary contusions - patchy/diffuse distribution of interstitial to alveolar patterns
3. diaphragmatic hernia - soft tissue or air-filled structures in pleural space, lateral displacement of heart, lungs, and trachea, absence of distinguishable diaphragmatic contour
4. rib fractures

Question 10

What supportive care is recommended for cases of thoracic trauma?

Answer 10

• supplemental oxygen
• sedation/analgesia
• stabilize patients in shock with cautious fluid resuscitation

Question 11

What are 4 parts to injury-specific treatment of thoracic trauma?

Answer 11

1. pneumothorax - thoracocentesis at the 7th-9th ICS, cranial to the rib, dorsal 1/3 of chest, thoracostomy tube recommended if continuous/recurrent
2. pulmonary contusion - time and supplemental oxygen, mechanical ventilation if severe
3. diaphragmatic hernia - thoracocentesis and trocarization if stomach is involved, surgery to replace viscera and repair defect
4. rib fractures - surgery NOT required, analgesia with opioids +/- lidocaine, ketamine CRI, intercostal nerve block