1 CHEST TRAUMA
Dec 17, 2015
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CHEST TRAUMA
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Blunt Trauma to the Chest
• Common result of industrial, military and road trauma
• Chest x-ray important in evaluating lung, mediastinal and vascular conditions
• Injury to great vessels, life threatening -90% die immediately
• Two thirds of victims of major blunt trauma suffer from a thoracic injury
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Blunt Trauma to the Chest
• 50% of remainder die within 24 hours if undiagnosed
• 2-5% of those who survive present later with an aortic aneurysm
• Diagnosis often hindered by other injuries • Chest injuries account for 20 -25% of the deaths,
mainly as a result of injuries from road accidents • 70% of multisystem injuries include significant
thoracic injuries
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Blunt Trauma to the Chest
• Chest x-ray is non specific, though it may demonstrate first clues – there is some relationship between fractures
of the 1st and 2nd ribs with aortic tears – caudal displacement of posterior upper ribs
with thoracic aortic injury
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Blunt Trauma to the Chest
• Aortic contour and mediastinal widening may be suggestive of haemothorax
• Aortography will confirm the presence of aortic injury, with high sensitivity and specificity
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Blunt Trauma to the Chest
• Conventional CT unable to confirm aortic tear, though will show mediastinal widening and haematoma
• Spiral CTA will be able to show aortic tear and extent of damage or whether the tear originates from the venous system
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Blunt Trauma to the Chest
• Spiral CTA will also demonstrate whether mediastinal widening or haematoma is due to small vessel damage
• Aortography may well be the only option which has the capacity to identify the: – involvement – size and location – direction of an aortic tear
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Pneumothorax
• There are two main forms: – Closed – Valvular
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Pneumothorax
• Closed – There is no air movement between the lung
and the pleural space,
• Valvular – Air enters on inspiration and remains on
expiration, – This will lead to an increase in pressure within
the thoracic cavity, – Substantial ‘side effects’ occur as the
pressure increases.
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Pneumothorax
• Air enters the pleural cavity through penetrating, open chest wound on inspiration. Negative pressure has been lost, thus collapsing the lung towards the mediastinum, reducing venous return to the heart. The shift of the mediastinum towards the opposite side compresses the ‘unaffected lung’.
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Pneumothorax
• During the expiration phase, the chest wall contracts, air will be expelled from the pleural cavity through the wound. The mediastinum shifts towards the affected side, beyond its normal central position, thus causing distortion of the vena cava.
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Tension Pneumothorax
• Air enters pleural cavity through lung wound. Negative intrapleural pressure is lost and the affected lung collapses, the mediastinum shifts towards opposite side, causing impaired ventilation.
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Tension Pneumothorax
• Upon expiration, intrapleural pressure rises, thus closing off the wound. Successive respiration phases increase this pressure thus causing further shift of structures to the opposite side. The diaphragm is depressed and venous return is impaired.
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Pneumothorax
• Well seen on conventional chest radiographs • Follow up chest radiographs necessary after
thoracosotomy tube has been inserted • 60% of patients with a lacerated bronchial tree
will have a pneumothorax – 25% of these will have a tension pneumothorax – 1 in 20 will have bilateral pneumothoracicies
• Fractures of the first 5 ribs a common finding with a pneumothorax
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Pneumothorax
• Clues that might indicate the presence of a pneumothorax if the classic findings of pneumothorax are not present on a supine chest radiograph are: – The deep sulcus sign ; abnormal deepening
of the costophrenic angle on the affected side– The double diaphragm sign ; the impression
of two diaphragms on the affected side– Visualisation of pericardial fat
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Flail Chest
• A loss of stability of the chest wall due to multiple rib fractures, with a rib being fractured in two places
• Insufficient expansion of the thorax and a corresponding increase energy expenditure for breathing to be effective
• 20 –30% increase in the likelihood of adult respiratory distress syndrome [ARDS], with a flail chest
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Flail Chest
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• On inspiration, the chest expands, and the diaphragm descends. The flail section sinks inwards, impairing the ability to produce negative intrapleural pressure. The trachea and mediastinum shift to the uninjured side, thus reducing the expansion of that lung.
Flail Chest
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• When the chest contracts and the diaphragm rise on expiration, the flail section bulges outwards, thus impairing the expiratory effect.
• The trachea and mediastinum shift now towards the injured side
Flail Chest
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Rib fractures causing flail chest
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Haemothorax
• May occur through either penetrating or non penetrating injuries. The larger the haemorrhage the greater the danger vital functions and shock.
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Haemothorax
• Haemothorax implies that the negative pressure in the intrapleural space still exists, therefore the nature of the haemorrhage is typical of a pleural effusion, in terms of its radiographic effect.
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Haemothorax
• 3 examples of a haemothorax – A = small haemorrhage of about 300-350 mls – B = Moderate haemorrhage up to 1500 mls – C = massive haemorrhage over 1500 mls.
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PLEURAL EFFUSION
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Sternal Fractures
The fracture itself is not important • The association with potential serious
injuries to the: • Aorta • Great vessels • Pulmonary contusion • Cardiac trauma Differential Diagnosis is far more important
• Sternal fracture require a lateral chest radiograph
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Aortic and Great Vessel Injuries
• Acceleration and traction forces are the major mechanism for thoracic and great vessel injuries – Horizontal deceleration create shear forces at the aortic isthmus – Vertical deceleration displace the heart caudally, displacing itinto
the left pleural cavity and acutely straining the ascending aorta-innominate artery junction
– 35 –90% of patients with thoracic aortic rupture die at the scene
• Chest radiographs is viewed for mediastinal widening, which is 90% sensitive and 10% specificity for traumatic aortic rupture
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36CARDIAC TAMPONADE
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Diaphragm Injuries
• Rupture of the diaphragm occurs in 1 –3% of patients with blunt chest trauma, usually from MVA’s
• Injury most common the left side due to the protective effect of the liver on the right
• Nearly all patients have associated injuries with a mortality rate of about 15%
• Chest radiographs are a useful starting point, though less than half the documented cases of rupture had chest findings
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Misplaced CVP line in jugular vein
39Nasogastric tube in bronchus
40Misplaced chest tube
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