Author:
Benjamin I.Liotta
Christopher J.Coyne
Description
- Significant source of morbidity and mortality in the U.S.
- ∼12 thoracic trauma victims per million population per day
- ∼33% of these injuries require hospital admission
- Directly responsible for 20-25% of all deaths attributed to trauma
- Contributing cause of death in 25% of patients who die from other traumatic injuries
Etiology
- Common mechanisms of injury include:
- Motor vehicle collisions (70-80%)
- Motorcycle collisions
- Pedestrians struck by a motor vehicle
- Falls from great heights
- Assaults
- Blast injuries
- Sports-related injuries
- Injuries can result from direct blunt force to the chest or from forces related to rapid deceleration
Signs and Symptoms
- Obvious contusion, wound, or other defect of the chest wall
- Paradoxical chest wall movement suggests flail chest segment (usually occurs in combination with other injuries)
- Hypotension
- Some patients with severe intrathoracic injuries, such as traumatic aortic disruption, may have no visible external signs of trauma
History
- Time of injury
- Mechanism of injury
- Estimates of motor vehicle accident (MVA) velocity and deceleration
- Loss of consciousness
- Chest pain
- Pain with deep inspiration or cough
- Dyspnea
Physical Exam
- Unilaterally absent breath sounds
- Crepitus or subcutaneous air in the chest wall
- Decreased or absent breath sounds
- Tenderness to palpation on the chest wall
- Jugular venous distention
- Tracheal deviation away from midline
- Hyper-resonance to percussion on involved side
Essential Workup
- Check airway, breathing, and circulation (ABCs) to determine the patient's stability
- Focused exam of the chest:
- Respiratory effort and rate
- Chest wall excursion
- Crepitus
- Subcutaneous air
- Breath sounds and heart sounds
- Presence of jugular venous distention
- A FAST exam should be performed to assess for evidence of pericardial effusion
- Consider US for detecting small pneumothoraces, especially given the poor sensitivity of supine CXR in detecting such injuries
- Obtain a supine CXR immediately:
- Avoid an upright CXR because of potential for other injuries (especially spinal injuries)
- ECG and monitor to detect myocardial ischemia or dysrhythmias
Diagnostic Tests & Interpretation
Lab
- Baseline hemoglobin
- Pulse oximetry
- ABG
- Serum lactate
- Type and cross-match
- Coagulation profile
- Cardiac enzymes when indicated
- Periodic chemistry panel for patients receiving significant fluid resuscitation
Imaging
- CXR is the initial radiologic study of choice:
- If CXR reveals widened mediastinum and patient hemodynamically stable, repeat film in upright position
- Chest CT is more specific for pneumothoraces and pulmonary contusions/occult injuries
- Chest CT with contrast, or aortic angiogram, is useful in identifying aortic and large-vessel injuries
- Consider using the NEXUS Chest CT criteria in stable, awake, nonintoxicated patients. If all criteria are absent, chest CT may not be necessary:
- Abnormal CXR
- Distracting injury
- Chest wall tenderness
- Sternal tenderness
- Thoracic spine tenderness
- Scapular tenderness
- Rapid deceleration mechanism, i.e., 40 mph
- MVC or fall >20' (including [7] increases sensitivity, decreases specificity)
- Thoracic US can be efficiently used for detecting pneumothoraces and pericardial injuries. The sensitivity, specificity, and overall accuracy in the ED setting for such injuries is >90%
- Esophagoscopy for direct endoscopic visualization if esophageal injury suspected
- Contrast esophagogram (with water and then barium) for possible esophageal injuries if esophagoscopy negative, but patient at risk for esophageal injury (e.g., pneumomediastinum):
- Combination of these 2 tests in sequence reaches close to 100% sensitivity
- ECG if sternal tenderness is present or abnormalities on cardiac monitor
Diagnostic Procedures/Surgery
- If the patient is unstable, emergency thoracotomy may be necessary to repair a traumatic aortic disruption
- If there are signs of cardiac tamponade, and patient is stable, perform an echocardiogram urgently:
- Pericardial effusions, wall motion defects, aortic injuries, valvular or other intracardiac pathology may also be identified
- If there are signs of cardiac tamponade and the patient is unstable, consider emergent pericardiocentesis, followed by immediate transport to the OR for a pericardial window
- If there is evidence of an aortic tear on imaging, the patient may require emergent surgical or endovascular repair
- Bronchoscopy often indicated for possible upper airway injuries (e.g., a large persistent air leak after chest tube)
Pregnancy Prophylaxis |
- In pregnant patients, remember to use the least amount of radiation available and to shield the uterus during imaging when possible
- Take note of the differences in anatomy of the thoracic cavity in pregnant patients, as well as differences in lab values, intravascular volume, and cardiovascular physiology
- See “Pregnancy, Trauma in,” for details
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Differential Diagnosis
- Simple pneumothorax
- Tension pneumothorax
- Open pneumothorax
- Hemothorax
- Rib fractures
- Flail chest
- Sternoclavicular fractures/dislocations
- Pulmonary contusion
- Myocardial contusion
- Myocardial rupture
- Cardiac (pericardial) tamponade
- Traumatic aortic disruption/Injury
- Esophageal injury
- Large vascular injury (subclavian artery, pulmonary artery)
- Tracheobronchial injury
- Diaphragmatic injury
Pediatric Considerations |
The rib cage is highly elastic in children and can withstand significant forces without overt signs of external trauma and can underestimate even major intrathoracic injuries- Retrospective studies have proposed limiting chest CT in pediatric trauma to patients with a vehicle-related mechanism or an abnormal CXR
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Geriatric Considerations |
| Elderly patients have been shown to have greater respiratory complications, including ARDS and pneumonia, than younger patients in the setting of blunt chest trauma. This is especially true in those >85 yr of age |
Prehospital
- All patients with any signs of life in the field should be transported to a trauma center
- Full spinal precautions should be employed
- Needle decompression is indicated for tension pneumothorax:
- Unilaterally absent breath sounds
- Hypotension
- Jugular venous distention
- Hyper-resonance to percussion
- If large, open pneumothorax exists, tape an occlusive dressing on 3 sides only to prevent causing a tension pneumothorax
- Do not delay transport to hospital for IV access
Initial Stabilization/Therapy
- ABCs management; intubate patient early if signs of respiratory insufficiency, shock, or altered mental status exist
- Resuscitation attempts should be initiated only in patients who arrive in the ED with vital signs
- Any patient who presents in blunt traumatic arrest is not likely to survive a thoracotomy in the ED, and it is therefore generally not indicated in this group
- If the patient's condition is unstable and clinically shows signs of a tension pneumothorax, perform needle thoracostomy and place a chest tube immediately afterward
- Do not wait to obtain a CXR
- Place chest tube on the affected side or bilaterally if injury site is unclear
- Deliver oxygen by nonrebreather face mask for stable patients
- Obtain vascular access, preferably 2 large-bore IV lines (>18G)
- Maintain spinal immobilization
ED Treatment/Procedures
- Tube thoracostomy if pneumothorax or hemothorax is identified:
- 36F chest tube in an adult
- In children, use the largest tube that the intercostal space will accommodate
- Provide resuscitation with isotonic fluids and blood products as necessary:
- Aggressive fluid resuscitation may be harmful if severe pulmonary contusions exist (consider permissive hypotension)
- Workup for associated intra-abdominal injuries (e.g., with abdominal US, abdominal CT scan, less commonly diagnostic peritoneal lavage):
- Patients with chest trauma frequently have concomitant intra-abdominal injuries
Medication
ALERT |
- This practice is under debate and becoming less utilized, so know your hospital's protocol
- Judicious doses of short-acting analgesics (fentanyl 1-2 mcg/kg IV, morphine 0.1 mg/kg IV) as needed for pain control
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Disposition
Admission Criteria
- Patients with conduction blocks, frequent ectopy, or ischemic changes visible on ECG should be admitted to a monitored setting for possible myocardial contusion
- Hemodynamically unstable patients should go to the OR on an emergency basis for thoracotomy or laparotomy
- >1,000-1,500 mL of blood drawn out of the chest tube on initial insertion indicates need for thoracotomy/operative management
- >200 mL of blood per hour from chest tube for several hours suggests the need for operative intervention
- Patients with significant rib fractures should be admitted for pain control:
- Consider epidural catheter for analgesia
- Patients who lose vital signs in the ED should undergo rapid open thoracotomy
Discharge Criteria
The NEXUS Chest criteria can be used to help identify low-risk patients who can be safely discharged with a normal CXR - absence of all NEXUS criteria had a sensitivity of 99.2% (NPV 99.8%) for major injury and a sensitivity 95.4% (NPV 93.9%) for any clinically significant injury
- Alternatively, patients with clinically insignificant chest wall contusions and an initial negative upright CXR may be observed for 6 hr in the ED and often be discharged if a repeat radiograph at that time reveals no pneumothorax, hemothorax, or pulmonary contusion, the patient is able to breathe deeply and to cough, remains clinically stable, and has no other significant injuries
Issues for Referral
- Notify trauma surgeon promptly about patients with significant injuries requiring surgical intervention or admission
- Indications for emergent surgical referral:
- Traumatic thoracotomy with loss of chest wall integrity
- Blunt diaphragmatic injuries
- Massive air leak following chest tube insertion
- Massive hemothorax or continued high rate of blood loss via the chest tube (i.e., 1,500 mL on insertion of tube or continued loss of 200-300 mL/hr)
- Radiographically or endoscopically confirmed tracheal, major bronchial, or esophageal injury
- GI tract contents recovered on chest tube placement
- Cardiac tamponade
- Radiographic confirmation of a great-vessel injury
- Embolism or missile into pulmonary artery, great vessel, or heart
Follow-up Recommendations
- Patients should be closely followed by trauma or cardiothoracic surgeons after hospital discharge, as indicated, depending upon the injuries discovered and treatment rendered
- Patients with thoracostomy tubes should have a CXR and routine wound care follow-up within 48 hr to remove the dressing and reassess clinical status