Pleural Effusion and Pneumothorax Flashcards
Under normal circumstances, what is the volume of the pleural space?
1-20cc
Describe pleural fluid
clear, odorless with some nucleated cells whose function is lubrication of the pleural surface
What is the cellular composition of pleural fluid?
less than 1.5l/ul
70-80% macrophages
10% lymphocytes
2% PMNs
Normal protein conc in the pleural space?
1-1.5g/dL
What factors contribute to the development of pleural effusion?
- hydrostatic pressure
- lymphatic drainage
- colloid oncotic pressure
- tissue pressure
airway pressure does not
T or F. The parietal pleura has a low hydrostatic pressure
F. It is high which promotes movement of fluid into the pleural space through junctions (100ml/hr)
T or F. The visceral pleura has a low hydrostatic pressure
T. So it functions to move fluid out (300ml/hr)
What is the difference between a transudate or an exudate?
In a pleural effusion, different fluids can enter the pleural cavity. Transudate is fluid pushed through the capillary due to high pressure within the capillary (i.e. low proteins). Exudate is fluid that leaks around the cells of the capillaries caused by inflammation.
What are the pressure-based causes of pleural effusion?
- increased hydrostatic pressure
- decreased pleural pressure
- increased OR decreased oncotic pressure
When are hydrostatic pressures increased?
heart failure (transudate)
When are pleural pressures decreased?
atelectasis (transudate)
When are oncotic pressures increased?
inflammation (exudate)
When are oncotic pressures decreased?
low albumin (transudate)
T or F. In pleural effusion due to CHF, both the parietal and visceral pleura are adding fluid into the space
T. Oncotic pressure gradient not affected
Characteristics of CHF pleural effusion
- frequently bilateral
- cardiomegaly
The quantity of effusion related to CHF is based on what?
proportional to elevation in pulmonary artery capillary wedge pressure (24+ mm Hg)
What are some pathologies that might promote an exudative pleural effusion?
- infection
- inflammation
- cancer
What happens to the oncotic pressure gradient in exudate rich pleural effusions?
it decreases. Hydrostatic pressures not affected
T or F. In pleural effusion due to inflammation, both the parietal and visceral pleura are adding fluid into the space
T.
Physical findings of pleural effusion?
- dullness to percussion
- decreased vocal fremitus