Pleural Effusion

Question 1

Pleural surface composed of what 3 components?

Answer 1

• mesothelial layer (single layer of cells)
• basement membrane
• connective tissue (w/ blood vessels, lymphatics, and nerves)

Question 2

2 types of pleura?

Answer 2

Visceral, Parietal

Question 3

2 major forces that control arrangement of free fluid in pleural space?

Answer 3

gravity, elastic recoil of lung

Question 4

Mesothelial cell distribution in visceral vs parietal pleura?

Answer 4

Visceral - loose

Parietal - Tight

Question 5

Mesothelial cell junction in visceral vs parietal pleura?

Answer 5

Visceral - Tight

Parietal - loose

Question 6

Microvilli distribution in visceral vs parietal pleura

Answer 6

Visceral - dense

Parietal - sparse

Question 7

Normal description of pleural fluid (volume, color, cell composition, protein concentration)

Answer 7

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)

Question 8

Simple definition of pleural effusion?

Answer 8

Collection of fluid within the pleural space

Question 9

Pleural effusion due to what factors (4)? Of these, which 2 are most important

Answer 9

1. Hydrostatic pressure
2. Colloid osmotic pressure
3. Tissue pressure
4. Lymphatic pressure

1 & 2 = most important factors

Question 10

Which pleura is under systemic circulation? via what arteries?

Answer 10

Parietal pleural - systemic circulation (intercostal arteries)

Question 11

Which pleura is under pulmonary circulation

Answer 11

Visceral

Question 12

Which pleura has a high hydrostatic pressure at baseline?

Answer 12

Parietal >>> Visceral, what creates gradient

Question 13

Which pleural is in charge of fluid absorption?

Answer 13

Visceral pleura absorbs fluid(Parietal forms). Same concept as hydrostatic pressure gradient

Question 14

Movement of proteins and cells within pleural space occurs via what pleura? Via what drainage pathway?

Answer 14

Parietal pleura only has lymphatic drainage that can remove proteins, particles, and cells that may accumulate.

Visceral pleura DOES NOT have lymphatic drainage channels

Question 15

Repeat concept. Pleural effusion occurs due to what 2 important factors?

Answer 15

Change in hydrostatic tissue forces OR oncotic pressure gradient

Question 16

Pleural effusions divided into what 2 types?

Answer 16

exudates, transudates

Question 17

Protein rich fluid = ?

Answer 17

exudate

Question 18

protein poor fluid = ?

Answer 18

transudate

Question 19

CHF patients have pleural effusions via what primary factor? Type of fluid produced?

Answer 19

Increased visceral hydrostatic pressure, transudate

Question 20

Low albumin and pleural effusion. What force? what type of protein fluid?

Answer 20

Decreased oncotic pressure, transudate

Question 21

Atelectasis and pleural effusion. What force? What type of protein fluid?

Answer 21

Increased negative pleural pressure, transudate

Question 22

Inflammation and pleural effusion. What force? What type of protein fluid

Answer 22

Increased oncotic pressure due to increased capillary permeability, produces EXUDATE

Question 23

Heart failure, atelectasis, low albumin, and inflammation/infection. Which of the 4 is the only one associated with exudate?

Answer 23

Inflammation/infection; other 3 associated with transudate

Question 24

Visceral pleura feature in CHF (fluid formation or fluid absorption affected)?

Answer 24

Shifts from fluid absorption to fluid formation due to increased visceral hydrostatic pressure. This causes more fluid to remain within the pleural space

Question 25

Oncotic pressure gradient not affected in what type(s) of pleural effusion?

Answer 25

Pleural effusions seen in CHF, atelectasis

Question 26

Hydrostatic pressure not affected in what type(s) of pleural effusions?

Answer 26

Decreased oncotic pressure pleural effusions (i.e. nephrotic syndrome); Increased oncotic pressure (capillary permeability) seen with infections/inflammation

Question 27

Bilateral effusion with cardiomegaly. Most likely to be?

Answer 27

CHF

Question 28

Bilateral effusion without cardiomegaly. Name possibly condition(s)?

Answer 28

Malignancy, lupus, RA, nephrotic syndrome, esophageal rupture, cirrhosis with ascites

Question 29

Light Criteria for transudate

1. Pleural/serum protein ratio?
2. Pleural/serum LDH ratio?
3. Serum LDH?

Answer 29

1. ≤ 0.5
2. ≤ 0.6
3. ≤ 200 U/L

Question 30

Light criteria for Exudate

1. Pleural/serum protein ratio?
2. Pleural/serum LDH ratio?
3. Serum LDH?

Answer 30

1. > 0.5
2. > 0.6
3. > 200 U/L

Question 31

2 malignancies most likely to cause pleural effusion?

Answer 31

Breast and Lung (makes anatomical sense)

Question 32

Mononuclear infiltration on evaluation of the pleural fluid. What is most likely the causative agent( there are 3)?

Answer 32

Tuberculosis, Malignancy, Sarcoidosis

Question 33

How would you discern that the RBCs in the specimen are from a traumatic tap?

Answer 33

non-uniform color distrubtion during aspiration (really blood at first, then it clears are you aspirate more fluid)

Question 34

What cause of pleural effusion will 100% of the time have a pleural fluid acidosis?

Answer 34

Esophageal rupture (Empyema is also almost always acidic)

Question 35

Most common cause of amylase in the pleural fluid?

Answer 35

Acute pancreatitis; somehow the amylase leaks through the diaphragm into the pleural space

Question 36

What is the indication for a thoracentesis?

Answer 36

Perform thoracentesis if > 10 mm of fluid in pleural space on lateral deubitus X-ray

Question 37

Describe the typical patient that gets a primary sponataneous pneumothorax

Answer 37

Someone that looks like TJ… Or Jacob (too soon?); Male predominance of 4:1

No identifiable lung disease

Question 38

Secondary spontaneous pneumothorax occurs in what type of patients?

Answer 38

Those with underlying lung disease:

Obstructive lung disease (COPD, asthma, CF)

Interstitial lung disease

Infections

Question 39

Tension Pneumothorax primarly occurs in patients that are under what?

Answer 39

mechanical ventilation (positive pressure ventilation)

Question 40

What is the worst complication of a tension pneumothorax? Why does it happen?

Answer 40

Complete circulatory collapse and death; the intrapleural pressure builds up and compresses the right atrium/ventricle–> no venous return or cardiac output

Question 41

What is commonly seen on CT in a patient with spontaneous pneumothroax?

Answer 41

Subpleural blebs

Question 42

2 clinical signs of someone with a tension pneumothorax?

Answer 42

Hypoxemia and Hypotension

Question 43

Treatment for someone with a tension pneumothorax?

Answer 43

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

Question 44

Where do you needle decompress (anatomical location)?

Answer 44

2nd ICS, midclavicular

Question 45

If there are > 5% mesothelial cells in pleural fluid, what disease process can you exclude?

Answer 45

TB, TB makes mesothelial cells drop, will be < 5% in possible TB

Question 46

Acid fast bacillus test is + in what % of TB patients? Why is this relevant?

Answer 46

Only 5% of TB patients will have +AFB (acid fast bacillus).

KEY POINT: a -AFB doesn’t rule out TB