Chest Injuries Flashcards
what is a pneumothorax
it is when air collects in the pleural space due to lung injury (can lead to partial/ complete pulmonary collapse)
what are the subclassifications of pneumothorax
- spontaneous pneumothorax
- primary/ secondary - traumatic pneumothorax
what is the life threatening variant of pneumothorax
tension pneumothorax
NB: any pneumothorax can develop into a tension pneumothorax if not treated
what is a primary spontaneous pneumothorax
its a pneumothorax that occurs in patients without any apparent underlying lung disease
what causes a primary spontaneous pneumothorax
rupture of subpleural apical blebs
what are risk factors of primary spontaneous pneumothorax
- slim, tall stature body part
- male sex
- young age
- smoking
what is a secondary spontaneous pneumothorax
its one that is as a result of a complication of a lung disease
what things can cause a secondary spontaneous pneumothorax
-COPD- rupture of bullae in emphysema
-infections like pulmonary TB, pneumocystis pneumonia
-cystic fibrosis
-marfan syndrome
what causes a traumatic pneumothorax
- blunt trauma e.g. motor vehicle accident, rib fractures
- penetrating injury e.g. gunshot, stab wound
-iatrogenic e.g. mechanical ventilation with high PEEP, thoracentesis, lung biopsy
whats the pathophysiology of a tension pneumothorax
-its caused by a one way valve effect, where during inspiration air enters the pleural space but during expiration the one way valve closes and air is unable to exit the pleural space
- this causes an increase in positive pressure within the chest as air continues to accumulate
- there is the collapse of the ipsilateral lung and compression of the contralateral lung, trachea, heart and superior vena cava
- this results in hypoxia as the lungs are both being mechanically compressed
-there is impaired cardiac filling (due to compression of the heart) as well as reduced venous return (due to increased intrathoracic pressure) hence causing obstructive shock
what are clinical features of a tension pneumothorax
- sudden severe ipsilateral pleuritic chest pain
- reduced/ absent breath sounds on the affected side
- hyper-resonant on percussion on affected side
- decreased fremitus on affected side
- acute respiratory distress (cyanosis, tachypnea, hypoxia, diaphoresis)
- reduced chest expansion on the affected side
- distended neck veins
- hemodynamic instability ( tachycardia, hypotension)- obstructive shock
- tracheal deviation
how do you diagnose tension pneumothorax
its mainly a clinical diagnosis
on an xray how will a pneumothorax present
- theyll be a line separating the lung from the pleural space
- theyll be absent lung markings
- inferior displacement of the diaphragm on the ipsilateral side
- shifting mediastinum toward the contralateral side
- tracheal deviation toward the contralateral side
what is the first line treatment for a tension pneumothorax
needle decompression to equilibrate pressure between the pleural space and atmosphere
- done by inserting a 14G cannula into the 2nd ICS, MCL or
- insert the cannula into the 4th/5th ICS, between the anterior and midaxillary line (safe triangle)
what does needle decompression do for a tension pneumothorax
it changes the tension pneumothorax into a simple pneumothorax (its a temporary measure)
