SM_172a: Pleural Disease Flashcards
Describe the histology of the pleura
Meosthelial cells bordering pleural space, then connective tissue, then alveolar space
______ pleura lines the lung, while ______ pleura lines the chest wall
Visceral pleura lines the lung, while parietal pleura lines the chest wall
(pleural space is between the two)
There are ____ pleural spaces
There are 2 pleural spaces
Pleural fluid is formed in the _______ pleura
Pleural fluid is formed in the parietal pleura
- Visceral pleura is thicker
- Visceral pleura drains into low pressure pulmonary veins, while parietal pleura drains into systemic veins
- Parietal pleura has lymphatic stoma
What is the Frank-Starling equation?
Describe pleural fluid flow
- Hydrostatic pressure high in small capillaries in parietal pleura which causes fluid to move into pleural space
- Lymphatic stoma draw fluid back into lymphatic drainage system
Pleural effusion forms as a result of an imbalance between _____ and _____
Pleural effusion forms as a result of an imbalance between pleural fluid filtration and pleural fluid clearance
What are the 5 factors that can lead to pleural effusion?
- Increased microvascular hydrostatic pressure (congestive heart failure)
- Decreased microvascular oncotic pressure (nephrotic syndrome)
- Obstruction to lymphatic drainage (malignancy)
- Decreased pleural space pressure (trapped lung)
- Increased permeability of capillaries or pleural lining (parapneumonic effusion)
Describe the presentation of pleural effusion
- Often asymptomatic
- Cough
- Dyspnea
- Dullness to percussion
- Decreased breath sounds
What is a tension pleural effusion?
- One hemothorax fills up with fluid
- Exerts mass effect on mediastinum
- Impedes venous drainage and right and left heart filling
What is the CXR finding corresponding to pleural effusion?
Dense opacification w/ meniscus sign (layering of fluid)
(need confirmatory testing to determine how much is pleural fluid and how much is atelectasis, CXR can also miss pleural effusion)
Which arrow represents an pleural effusion?
Middle arrow (anechoic space represents pleural fluid)
______ is the procedure used to evaluate pleural effusion
Thoracentesis is the procedure used to evaluate pleural effusion
What are Light’s criteria?
Pleural effusion is exudative if any one of the following is true:
- Pleural fluid total protein / serum total protein > 0.5
- Pleural fluid LDH / serum LDH > 0.6
- Pleural fluid LDH > 2/3 of upper normal value of serum LDH
If at least one of the Light criteria for pleural effusion is met, the pleural effusion is ______
If at least one of the Light criteria for pleural effusion is met, the pleural effusion is exudative
______, ______, and ______ are causes of transudative pleural effusions
CHF, cirrhosis, and nephrotic syndrome are causes of transudative pleural effusions
_______, _______, _______, _______, and _______ are causes of exudative pleural effusions
Parapneumonic, malignancy, autoimmune disease, pulmonary embolism, and pancreatitis are causes of exudative pleural effusions
What additional testing is done for exudative pleural effusions?
- Cell count
- Neutrophilic: infection (likely bacterial)
- Lymphocytic: malignancy, TB, autoimmune disease
- pH: if <7.2 consider chest tube drainage b/c likely active infectious process
- Glucose
- Cultures
- Cytology
A neutrophilic exudative effusion is suggestive of a _____
A neutrophilic exudative effusion is suggestive of a bacterial infection
A lymphocytic exudative effusion is suggestive of _____, _____, or _____
A lymphocytic exudative effusion is suggestive of malignancy, TB, or autoimmune disease
The more acidic the exudative pleural fluid is, the more we are concerned about an ______
The more acidic the exudative pleural fluid is, the more we are concerned about an active infectious process
_____ is purulent infection in the pleural space and an indication for chest tube
Empyema is purulent infection in the pleural space and an indication for chest tube
______ is triglyceride-rich fluid in the pleural space and most often results from injury to the ______
Chylothorax is triglyceride-rich fluid in the pleural space and most often results from injury to the thoracic duct
Describe the approach for diagnosing/sampling pleural effusion
______ is air in the pleural space
Pneumothorax is air in the pleural space
- Types: primary spontaneous, secondary spontaneous, traumatic/iatrogenic
Describe the characteristics of primary spontaneous pneumothorax
Primary spontaneous pneumothorax
- No underlying lung pathology
- No inciting event
- Young thin patients
- Recurrent rate high
Secondary spontaneous pneumothorax is spontaneous pneumothorax in the setting of ______
Secondary spontaneous pneumothorax is spontaneous pneumothorax in the setting of underlying lung disease
What is trapped lung?
Visceral pleura become inflamed, hypertrophied, and scarred -> impede lung expansion
Describe the imaging modalities using to diagnose pneumothorax
- Chest CT: gold standard
- CXR: acceptable if pneumothorax is moderate-large
- Ultrasound: increasingly utilized
The ultrasound finding diagnostic of pneumothorax is ______
The ultrasound finding diagnostic of pneumothorax is lung point
(half of pleura moving and half not moving)
Describe what occurs in an open pneumothorax
- Continuous connection between chest wall and atmosphere
- Pressure in intrapleural space will not get too high b/c air can flow in, causing pressure to equilibrate
Describe what occurs in a closed pneumothorax
Injury acts like a ball valve
- Air continues to fill up pleural space -> pressure becomes more positive -> impedes venous return and right and left heart filling -> pneumothorax
(concerned about pneumothorax when on positive pressure b/c intrapleural pressure rapidly exceeds pressure needed for venous return)
In tension pneumothorax, intrapleural pressure _____ atmospheric pressure, shifting trachea away from the affected side
In tension pneumothorax, intrapleural pressure rises above atmospheric pressure, shifting trachea away from the affected side
Subcutaneous emphysema is when ______ and is treated by ______
Subcutaneous emphysema is when air dissects bronchovascular bundles and enters into tissue and is treated with needle decompression
