Chapter 10: Recognizing Pneumothorax, Pneumomediastinum, Pneumopericardium, and Subcutaneous Emphysema Flashcards
How do you recognize a pneumothorax?
Visualization of the visceral pleural line
Convex curve of the visceral pleural line paralleling the countour of the chest wall
Absence of lung markings distal to the visceral pleural line
The deep sulcus sign of an inferiority displaced costophrenic angle seen on a supine chest
The presence of an air-fluid interface in the pleural space
How large is the pneumothorax?
Size measurement of pneumothorax on X-rays correlate poorly with CT scans of the actual size
There is poor circulation between the size of the pneumothorax and the degree of clinical impairment
What is the 2 cm rule and what disease does it correlate with?
Pneumothorax
If the distance between eh lung margin and the chest wall at the apex is <2cm, a chest tube is usually not needed; a distance >2cm usually requires chest tube drainage
What is the most important determinant in deciding whether a patient needs a chest tube?
Patient’s clinical status
What is a pneumothorax?
Air in the pleural space
What must you identify to diagnose a pneumothorax?
The visceral pleural white line
What are the pitfalls that resemble a pneumothorax?
Bullae
Skinfolds
Medial border of the scapula
What does a simple pneumothorax have?
It doesn’t have a shift of the heart or mobile mediastinal structures
What does a tension pneumothorax create?
Produces a shift of the heart and mediastinal structures AWAY from the side of the pneumothorax by virtue of a check-valve mechanism that allows air to enter the visceral pleural space but not leave
What do most pneumothoraces have?
Traumatic causes
What imaging is better at estimating the size of a pneumothorax?
A CT
What are other ways to diagnose a pneumothorax besides an upright CXR?
Expiration exposures
Decubitus views
Delayed images
What test detects a small pneumothorax?
CT
Why do spontaneous pneumothoraces occur?
They occur as a result of rupture of a small apical, subpleural bleb and they most often occur in younger men
How does a pulmonary interstitial emphysema occur and how are they read on an Xray?
Results from an increase in the intraalveolar pressure, which leads to rupture of an alveolus and dissection of air back toward the Hilar along the bronchovascular bundles
It is difficult to see on Xray