Pleural Effusion Flashcards
Pleural surface composed of what 3 components?
- mesothelial layer (single layer of cells)
- basement membrane
- connective tissue (w/ blood vessels, lymphatics, and nerves)
2 types of pleura?
Visceral, Parietal
2 major forces that control arrangement of free fluid in pleural space?
gravity, elastic recoil of lung
Mesothelial cell distribution in visceral vs parietal pleura?
Visceral - loose
Parietal - Tight
Mesothelial cell junction in visceral vs parietal pleura?
Visceral - Tight
Parietal - loose
Microvilli distribution in visceral vs parietal pleura
Visceral - dense
Parietal - sparse
Normal description of pleural fluid (volume, color, cell composition, protein concentration)
Thin layer w/ 1-20 cc of fluid
Clear, odorless
Nucleated cells (70-80% macrophages, mesothelial cells, and monocytes; 2% polymorphonuclear leukocytes; 10% lymphocytes)
1-1.5 g/dL protein (gives colloid oncotic pressure of 8 cm H2O)
Simple definition of pleural effusion?
Collection of fluid within the pleural space
Pleural effusion due to what factors (4)? Of these, which 2 are most important
- Hydrostatic pressure
- Colloid osmotic pressure
- Tissue pressure
- Lymphatic pressure
1 & 2 = most important factors
Which pleura is under systemic circulation? via what arteries?
Parietal pleural - systemic circulation (intercostal arteries)
Which pleura is under pulmonary circulation
Visceral
Which pleura has a high hydrostatic pressure at baseline?
Parietal >>> Visceral, what creates gradient
Which pleural is in charge of fluid absorption?
Visceral pleura absorbs fluid(Parietal forms). Same concept as hydrostatic pressure gradient
Movement of proteins and cells within pleural space occurs via what pleura? Via what drainage pathway?
Parietal pleura only has lymphatic drainage that can remove proteins, particles, and cells that may accumulate.
Visceral pleura DOES NOT have lymphatic drainage channels
Repeat concept. Pleural effusion occurs due to what 2 important factors?
Change in hydrostatic tissue forces OR oncotic pressure gradient
Pleural effusions divided into what 2 types?
exudates, transudates
Protein rich fluid = ?
exudate
protein poor fluid = ?
transudate
CHF patients have pleural effusions via what primary factor? Type of fluid produced?
Increased visceral hydrostatic pressure, transudate
Low albumin and pleural effusion. What force? what type of protein fluid?
Decreased oncotic pressure, transudate
Atelectasis and pleural effusion. What force? What type of protein fluid?
Increased negative pleural pressure, transudate
Inflammation and pleural effusion. What force? What type of protein fluid
Increased oncotic pressure due to increased capillary permeability, produces EXUDATE
Heart failure, atelectasis, low albumin, and inflammation/infection. Which of the 4 is the only one associated with exudate?
Inflammation/infection; other 3 associated with transudate
Visceral pleura feature in CHF (fluid formation or fluid absorption affected)?
Shifts from fluid absorption to fluid formation due to increased visceral hydrostatic pressure. This causes more fluid to remain within the pleural space
Oncotic pressure gradient not affected in what type(s) of pleural effusion?
Pleural effusions seen in CHF, atelectasis
Hydrostatic pressure not affected in what type(s) of pleural effusions?
Decreased oncotic pressure pleural effusions (i.e. nephrotic syndrome); Increased oncotic pressure (capillary permeability) seen with infections/inflammation
Bilateral effusion with cardiomegaly. Most likely to be?
CHF
Bilateral effusion without cardiomegaly. Name possibly condition(s)?
Malignancy, lupus, RA, nephrotic syndrome, esophageal rupture, cirrhosis with ascites
Light Criteria for transudate
- Pleural/serum protein ratio?
- Pleural/serum LDH ratio?
- Serum LDH?
- ≤ 0.5
- ≤ 0.6
- ≤ 200 U/L
Light criteria for Exudate
- Pleural/serum protein ratio?
- Pleural/serum LDH ratio?
- Serum LDH?
- > 0.5
- > 0.6
- > 200 U/L
2 malignancies most likely to cause pleural effusion?
Breast and Lung (makes anatomical sense)
Mononuclear infiltration on evaluation of the pleural fluid. What is most likely the causative agent( there are 3)?
Tuberculosis, Malignancy, Sarcoidosis
How would you discern that the RBCs in the specimen are from a traumatic tap?
non-uniform color distrubtion during aspiration (really blood at first, then it clears are you aspirate more fluid)
What cause of pleural effusion will 100% of the time have a pleural fluid acidosis?
Esophageal rupture (Empyema is also almost always acidic)
Most common cause of amylase in the pleural fluid?
Acute pancreatitis; somehow the amylase leaks through the diaphragm into the pleural space
What is the indication for a thoracentesis?
Perform thoracentesis if > 10 mm of fluid in pleural space on lateral deubitus X-ray
Describe the typical patient that gets a primary sponataneous pneumothorax
Someone that looks like TJ… Or Jacob (too soon?); Male predominance of 4:1
No identifiable lung disease
Secondary spontaneous pneumothorax occurs in what type of patients?
Those with underlying lung disease:
Obstructive lung disease (COPD, asthma, CF)
Interstitial lung disease
Infections
Tension Pneumothorax primarly occurs in patients that are under what?
mechanical ventilation (positive pressure ventilation)
What is the worst complication of a tension pneumothorax? Why does it happen?
Complete circulatory collapse and death; the intrapleural pressure builds up and compresses the right atrium/ventricle–> no venous return or cardiac output
What is commonly seen on CT in a patient with spontaneous pneumothroax?
Subpleural blebs
2 clinical signs of someone with a tension pneumothorax?
Hypoxemia and Hypotension
Treatment for someone with a tension pneumothorax?
NEEDLE DECOMPRESSION with a large bore needle; must do this prior to the chest tube to prevent circualtory collapse; then you put in the chest tube
Where do you needle decompress (anatomical location)?
2nd ICS, midclavicular
If there are > 5% mesothelial cells in pleural fluid, what disease process can you exclude?
TB, TB makes mesothelial cells drop, will be < 5% in possible TB
Acid fast bacillus test is + in what % of TB patients? Why is this relevant?
Only 5% of TB patients will have +AFB (acid fast bacillus).
KEY POINT: a -AFB doesn’t rule out TB
