Pulmonary Trauma, part 2 Flashcards
These suggest pneumomediastinum
Subcutaneous emphysema in the neck
Hamman’s sign
- crunching osund over the heart during systole
Pneumomediastinum in blunt chest trauma is most commonly the result of
Alveolar rupture,
followed by dissection along the bronchoalveolar sheath and subsequent spread of air to the mediastinum, a process known as the Macklin effect
Remarks on pneumomediastinum
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
Hemorrhage from pulmonary lacerations is most commonly seen in
the settting of displaced rib fractures
Remarks on aspiration during trauma
- Aspiration of gastric contents is common after severe trauma, especially if the patient was unconscious at any time
- 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
- There is no evidence to support the use of prophylactic antibiotics to prevent pulmonary infection after gastric aspiration
Key points in management of intrabronchial bleeding
- It is important to identify the involved lung and to keep the other lung as free of blood as possible
- If the hemorrhage is severe, a double-lumen endotracheal tube can be used as a temporizing measure to confine the bleeding to one lung**
- 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
Most tracheoronchial injuries occur where?
within 2 cm of the carina
or at the origin of lobar bronchi
Remarks on bronchopleural fistula
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
Remarks on tracheobronchial lacerations
- All lacerations of the bronchi involving more than 1/3 of the circumference should be operatively repaired.
- Untreated tracheal tears may result in severe mediastinitis or can lead to severe bronchial stenosis with atelectasis and repeated pulmonary infections
- intrathoracic tracheal transections is usually associated with two or more major injuries and is almost invariably fatal
Blunt injuries to the upper (cervical) trachea are usually found where
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
Diaphragmatic injuries are most commonly caused by
penetrating trauma,
particularly GSW of the lower chest or upper abdomen
Remarks on diaphragmatic blunt injuries
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
Favored approach for the diagnosis of isolated traumatic diaphragmatic injury
Laparoscopy
NGT placement with evaluation to see if the tube curves up from the abdomen into the chest may also be done.
If traumatic esophageal injury is suspected but there is no indication for immediate operative exploration, do what?
obtain CT angiography of the neck
Remarks on esophageal injuries
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.
Remarks on subcutaneous emphysema
Presume patients with subcutaneous emphysema to have an underlying pneumothorax, even if it is not visible on the chest radiograph
Most common bony injuries in chest trauma
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
Remarks on analgesia for chest wall pain
- A combination of opioids, benzodiazepines, topical lidocaine patch, and NSAIDs provides the most effective analgesia for mild to moderate chest wall pain
- 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
Remarks on flail chest
- The primary cause of the hypoxemia is contusion to the underlying lung
- Indication for early ventilatory support: fracture of 8 or more ribs, PO2 <80 mm Hg despite supplemental oxygen
- Early intubation and ventilatory assistance in patients with flail chest reduce mortality compared with delaying intubation until the onset of respiratory failure
Sternal fractures usually occur where?
At the body
These patients are at risk for air embolus
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
Air embolism management
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
NEXUX Chest Rules
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
Some considerations for early ventilatory assistance after thoracic trauma
RR >30-35 breaths/min
Vital capacity <10-15 mL/kg
Negative inspiratory force <25-30 cm H2O
