Pulmonary Trauma, part 2

Question 1

These suggest pneumomediastinum

Answer 1

Subcutaneous emphysema in the neck
Hamman’s sign
- crunching osund over the heart during systole

Question 2

Pneumomediastinum in blunt chest trauma is most commonly the result of

Answer 2

Alveolar rupture,
followed by dissection along the bronchoalveolar sheath and subsequent spread of air to the mediastinum, a process known as the Macklin effect

Question 3

Remarks on pneumomediastinum

Answer 3

Pneumomediastinum alone does not require further diagnostic testing or intervention unless the patient is symptomatic (chest pain, voice change, stridor), in which case a search for other serious injuries to the larynx, trachea, major bronchi, pharynx, or esophagus is essential

Question 4

Hemorrhage from pulmonary lacerations is most commonly seen in

Answer 4

the settting of displaced rib fractures

Question 5

Remarks on aspiration during trauma

Answer 5

1. Aspiration of gastric contents is common after severe trauma, especially if the patient was unconscious at any time
2. Radiographic changes may be delayed for up to 24 hours and can include consolidation virtually anywhere in the lungs, with the most common sites being the right middle and lower lung fields
3. There is no evidence to support the use of prophylactic antibiotics to prevent pulmonary infection after gastric aspiration

Question 6

Key points in management of intrabronchial bleeding

Answer 6

1. It is important to identify the involved lung and to keep the other lung as free of blood as possible
2. If the hemorrhage is severe, a double-lumen endotracheal tube can be used as a temporizing measure to confine the bleeding to one lung**
3. If a double-lumen ETT is not available, a standard tube may be inserted over a flexible bronchoscope into the unaffected lung, or an endotracheal tube can be purposely passed into the right mainstem bronchus as a diagnostic measure and the patient placed with the affected lung in the dependent position

Question 7

Most tracheoronchial injuries occur where?

Answer 7

within 2 cm of the carina
or at the origin of lobar bronchi

Question 8

Remarks on bronchopleural fistula

Answer 8

The air leak due to bronchopleural fistula following tube thoracostomy is continuous and massive.
High-frequency oscillation is the ventilator modality of choice to maintain gas exchange and expand the alveoli in the face of the massive gas leak

Question 9

Remarks on tracheobronchial lacerations

Answer 9

1. All lacerations of the bronchi involving more than 1/3 of the circumference should be operatively repaired.
2. Untreated tracheal tears may result in severe mediastinitis or can lead to severe bronchial stenosis with atelectasis and repeated pulmonary infections
3. intrathoracic tracheal transections is usually associated with two or more major injuries and is almost invariably fatal

Question 10

Blunt injuries to the upper (cervical) trachea are usually found where

Answer 10

at the junction of the trachea and cricoid cartilage
this most frequently occurs when the anterior neck strikes the steering wheel or dashboard in an automobile accident

Question 11

Diaphragmatic injuries are most commonly caused by

Answer 11

penetrating trauma,
particularly GSW of the lower chest or upper abdomen

Question 12

Remarks on diaphragmatic blunt injuries

Answer 12

More diaphragmatic injuries following blut trama are diagnosed on the **left hemidiaphragm.
This left-sided predominance is likely due to the protective effect of the liver on the right hemidiaphragm and the possible increased weakness of the left posterolateral diaphragm

Question 13

Favored approach for the diagnosis of isolated traumatic diaphragmatic injury

Answer 13

Laparoscopy

NGT placement with evaluation to see if the tube curves up from the abdomen into the chest may also be done.

Question 14

If traumatic esophageal injury is suspected but there is no indication for immediate operative exploration, do what?

Answer 14

obtain CT angiography of the neck

Question 15

Remarks on esophageal injuries

Answer 15

Despite the diagnostic and therapeutic advances, esophageal injuries are associated with significant morbidity and mortality, particularly if there is a delay in recognition and definitive management.

Question 16

Remarks on subcutaneous emphysema

Answer 16

Presume patients with subcutaneous emphysema to have an underlying pneumothorax, even if it is not visible on the chest radiograph

Question 17

Most common bony injuries in chest trauma

Answer 17

Rib fractures.
- Up to 50% of rib fractures (especially those involving the anterior and lateral portions of the first five ribs) are not apparent on conventional radiography, particularly in the first few days after injury
- with the exception of direct local trauma, it takes great force to fracture the first and second ribs

Question 18

Remarks on analgesia for chest wall pain

Answer 18

1. A combination of opioids, benzodiazepines, topical lidocaine patch, and NSAIDs provides the most effective analgesia for mild to moderate chest wall pain
2. An intercostal nerve block or serratus anterior plane block with a long-acting agent such as bupivacaine will relieve severe pain assoc’d with muscle spasm and ventilation for up to 12 hours

Question 19

Remarks on flail chest

Answer 19

1. The primary cause of the hypoxemia is contusion to the underlying lung
2. Indication for early ventilatory support: fracture of 8 or more ribs, PO2 <80 mm Hg despite supplemental oxygen
3. Early intubation and ventilatory assistance in patients with flail chest reduce mortality compared with delaying intubation until the onset of respiratory failure

Question 20

Sternal fractures usually occur where?

Answer 20

At the body

Question 21

These patients are at risk for air embolus

Answer 21

Patients with penetrating chest wounds who require positive-pressure ventilation
High ventilatory pressures, especially >50 cm H2O, may force air from an injured bronchus into an adjacent injured vessel.
Patients presenting with hemoptysis in the setting of penetrating chest trauma are at particular risk for this serious complication

Question 22

Air embolism management

Answer 22

If systemic air embolism is suspected or diagnosed, place the patient in a flat supine position with 100% oxygen applied, which may decrease air bubble size by displacing nitrogen and promoting resorption of the embolus.

There is NO evidence to support the theoretical benefit of the Trendelenburg (head down) position in arterial air embolism

Question 23

NEXUX Chest Rules

Answer 23

Presence of 1 or more criteria: cannot exclude intrathoracic injury and obtain chest imaging
Age >60 y/o
Rapid deceleration: fall >20 ft (>6 m); MVC >40 mph (>64 kph)
Chest pain
Intoxication
Abnormal alertness
Distracting painful injury
Tenderness to chest wall palpation

Question 24

Some considerations for early ventilatory assistance after thoracic trauma

Answer 24

RR >30-35 breaths/min
Vital capacity <10-15 mL/kg
Negative inspiratory force <25-30 cm H2O