Pleural Diseases

Question 1

What’s the blood supply to the parietal pleura?

Answer 1

Intercostal arteries.

Question 2

What’s the blood supply to the visceral pleura?

Answer 2

Pulmonary and a small amount of bronchial circulation.

Question 3

What drives a small net movement of fluid into the pleural space under normal conditions)?
Does the parietal and visceral pleura equally contribute?

Answer 3

Parietal pleura has both higher hydrostatic and higher oncotic pressure than the pleura space, but the hydostatic pressure is high enough to cause some net fluid movement.

There is no net fluid movement across the visceral pleura. (under normal conditions)

Question 4

How does fluid in the pleura space get reabsorbed?

What about of excess fluid production can they handle?

Answer 4

Stomata on the parietal pleaura - they’re concentrated inferiorly and directly connect with lymphatics.
Can reabsorb up to 28x normal production.

Question 5

What are the symptoms of pleura effusion?

they’re non-specific

Answer 5

Shortness of breath.
Cough.
Vague chest pressure or discomfort.
Pleuritic chest pain.
Orthopnea.
Signs and symptoms of underlying disease disease.

Question 6

How do palpation physical exam findings change in pleural effusion?

Answer 6

Decrease in chest wall excursion.

Decrease in tactile fremitus.

Question 7

How do percussion exam findings change in pleural effusion?

Answer 7

Dull to percussion.

Question 8

How do auscultation exam findings change in pleural effusion?

Answer 8

Diminished or absent breath sounds.
Pleural rub.
(no egophony)

Question 9

Most straightforward imaging to confirm a pleural effusion?

Answer 9

Chest x-ray - blunting of costodiaphragmatic angle.
(or shifting of mediastinal structures if massive)

But you can see it on CT, ultrasound.

Question 10

When should and effusion be tapped?

Answer 10

Thoracentesis should be done anytime there’s > 10 mm fluid (on ultrasound or lateral dicubitus CXR).

Question 11

Effusion color is useful.

Answer 11

Yeah…. in a fairly obvious way. But “straw-colored” fluid doesn’t tell you much.

Question 12

What’s the difference between transudate and exudate?

Answer 12

Transudate: from hydrostatic/oncotic pressure imbalance.
Exudate: from increased capillary permeability.

Question 13

How do Light’s criteria help you tell exudate vs. transudate?

Answer 13

If 1 or more of the following criteria are met, it’s exudate:
Pleural fluid:serum protein > 0.5.
Pleural fluid:serum LDH > 0.6.
Pleural fluid LDH > 2/3 upper limit of normal for serum.

Basically, if the fluid resembles serum in protein and LDH levels, it’s exudate.

Question 14

3 ways to get increased hydrostatic pressure -> transudate?

Answer 14

CHF.
Constrictive pericarditis.
SVC obstruction.

Question 15

3 ways to get decreases in oncotic pressure -> transudate?

Answer 15

Cirrhosis.
Nephrotic syndrome.
Hypoalbuminemia.
(all have not enough protein in serum)

Question 16

Why is there pleural effusion in SVC syndrome?

Answer 16

Recall that the parietal pleura is drained by the systemic circulation -> if the systemic circulation backs up… increased hydrostatic in parietal pleura -> effusion.

Question 17

2 most common types of cause of exudative effusions?

Answer 17

Infections and malignancy.

though PE, connective tissue disease, some drugs, and lots of other things can cause it

Question 18

Why would there be decreased glucose in the fluid?

How about low pH?

Answer 18

Highly metabolically active things, including infection, malignancy, rheumatoid arthritis, and esophageal rupture.

Question 19

3 types of cells that can be predominant when there’s increased cellularity of the effusion?

Answer 19

PMNs - infection.
Lymphocytes - Cancer, TB, chylothorax(?)
Eosinophils - trauma, PTX, asbestos, drug reaction, parasitic infecition.

Question 20

Treatment for pleural effusion?

Answer 20

Depends on the underlying cause…

and thoracentesis.

Question 21

3 classifications of exudative effusions?

Answer 21

Parapneumonic - not severe, doesn’t need therapy.
Complicated parapneumonic effusion (CPE).
Empyema.

Question 22

What distinguishes empyema and CPE from parapneumonic exudate?

Answer 22

Abnormal chemistries - low pH, low glucose, high PMNs.

Question 23

What distinguishes empyema from CPE?

Answer 23

Chemistries are the same, but empyema has frank pus and bacteria in the effusion.

Question 24

Treatment of CPE or empyema? (2 things)

Answer 24

ABx.

Drainage with chest tube / surgery.

Question 25

Larger effusions are more likely to be malignant.

Answer 25

okay. And it’s a bad prognostic sign.

Question 26

Treatment for malignant pleural effusion? (3 things)

Answer 26

Thoracentesis.
Treat underlying cancer.
Pleurodesis.

Question 27

What’s pleurodesis?

Answer 27

It’s a palliative treatment for a malignant effusion - drain fluid, spray in talcum powder… makes pleura stick together, reducing recurrent effusion.

Question 28

Autoimmune diseases that can cause pleural effusions?

Answer 28

Rheumatoid arthritis.
SLE.
(Effusions of SLE tend to be more painful.)

Question 29

Causes of pneumothorax (PTX)?

Answer 29

Spontaneous
Interstitial Lung Disease (ILD)
Emphysema
Asthma
Iatrogenic (procedures, mechanical ventilation)

Question 30

3 kinds of ILD that can lead to PTX?

Answer 30

ILD.
Lymphangioleiomyomatosis (LAM) -recurrent PTX in a young female.
Langerhans cell histiocytosis.

Question 31

Treatment for PTX?

Answer 31

Chest tube