The Pleura Flashcards
What is malignant mesothelioma?
Cancer of the pleural cells
How much pleural fluid do you have?
15-20ml
How is pleural fluid produced? Which layer produces most?
Through filtration, the parietal pleura produces more, mainly just due to the forces on the pleural membranes
What cells are in the pleural fluid?
Macrophages, lymphocytes usually filtered out from blood and mesothelial cells shed from peural surface
What pressure is the pleura at? Is there a gradient?
Negative pressure, yes, most negative at the base of the lung (-5) compared to -3 at the top
Differences pleural effusion/pneumothorax/harmothorax/empyema
pleural effusion - fluid in pleural space
pneumothorax- air in pleural space
harmothorax - blood in pleural space
empyema - pus in pleural space
What causes pleural effusion?
An imbalance in production and absorption of pleural fluid
What is transudate vs exudate
Different types of pleural fluid:
Transudate = think translocated, the cause is generally not lung related, more watery secretion (low protein, non inflammatory), produced purely through filtration
Exudate = wanted to exit real fast, high protein(3g/deciliter), high immune cells
What is Lights criteria
Distinguishes between transudates and exudates.
Compares plasma fluid to serum fluid for:
Protein concentration, lactate dehydrogenase and fluid.
What are causes of transudates? Is effusion usually bilateral/unilateral?
Common causes include organ failure eg heart failure, liver failure, kidney failure.
Presents often as bilateral effusions, often have subcutaneous oedema/fluid elsewhere in body too.
Common causes of Exudate
Pulmonary causes eg parapneumonic effusion associated with pneumonia.
Also can be secondary malignancy
Pulmonary emboli/clots in the lungs or benign asbestos effiusions.
Can an ultrasound be easily used bedside to monitor?
Yes
How much fluid is needed to be visible on CX
100-200ml
What is a loculation?
A small fluid pocket usually only picked up on CT scans. Usually likely to be infected or about to form pus.
How do you take pleural fluid sample?
With a simple green needle, sometimes under local anasthetic. An ultrasound will mark the spot.
Why do you need to drain fluid pH 7.2+ in pneumonia?
Likely to form PUS, infection more difficult to control.
Which protein and carb levels do we look for?
LDH - Lactacte dehydrogenase and glucose levels
What is a pneumothorax?
Air in the pleural space
Spontaneous pneumothorax can be caused by what? Who in usually? Presentations? Signs?
usually tall and thin men (primary spontaneous pneumothorax) - or those with pre existing lung disease (2ndry spontaneous pneumothorax) eg COPD. caused by “blebs” on lungs - which are weak spots which can spontaneously rupture.
Sudden onset of chest pain and SOB
Tachypneic, tachycardia, resonant chest, hypoxia
What is Iatrogenic caused by usually?
Some sort of healthcare intervention, eg biopsy/mechanical ventilation
What is tension pneumothorax? Is it a life threatening event?
When the trachea becomes deviated to one side and the air compresses all the structures over.
yes, life threatening because can compress heart, so less bp drops, compression of opposite lung can mean that o2 levels fall. Can escalate quickly to cardiac arrest.
Why are smaller pneumothoraxes easily missed?
Because they are generally at the apices (air rises) of the lungs, harder to see on X-Ray due to lots of other structures being there (clavicle, first rib)
What are the management options for pneumothorax?
Depends on condition of patient:
Observe (small pneumothorax, patient is well)
Aspiration (needle with syrynge to suck out air) - small pneumothorax but over 2cm in size, patient well
Chest drain insertion - usually left in place until pneumothorax completely resolves, common for large secondary pneumothoraxes
If it is the 2nd pneumothorax patient has had surgery may be best option as unlikely to heal by itself.
What is the recurrence rate for pneumothorax? Precautions after 1sr pneumothorax?
25-50%
Within 1st week of recovery from pneumothorax advised o flying and to avoid lifting heavy objects
