Diseases of the Pleural Space

Question 1

What are clinical signs of pleural disease?

Answer 1

shallow, rapid breathing
- dyspnea
- tachypnea
- orthopnea

Question 2

Define the characteristics of different types of pleural effusion.

Answer 2

1. Pure transudate. TP <2.5, cellularity <2500
   - water-like effusion, due to low albumen (PLN/ PLE)
   - Yorkies with lymphangiectasia
   - can provide colloid, diuretics, and tx underlying disease
2. Modified transudate. TP 2.5-7, cellularity 1000-7000
   - most common!
3. Exudate, TP > 7, cells > 7000
   - infectious, can be localized or systemic sepsis
   - cats: penetrating bite wounds; dogs: bite wounds, FB/ migrating grass awns
   - treatable with appropriate antibiotics
   - FIP

Question 3

How can NT-proBNT be used in the pleural effusion?

Answer 3

high NT-proBNT in feline effusion is linked to cardiogenic cause –> CHF leading to pleural effusion

Question 4

Does a low glucose in pleural effusion = sepsis?

Answer 4

No, though it’s true in ascites

Question 5

What are the 3 top differentials for modified transudate pleural effusion?

Answer 5

1. CHF, diagnosis based on echo
   - most common in dogs and cats
   - right sided heart failure, esp in cats (can look chyus)
   - increase in NT-proBNT in serum or plasma supportive of CHF
   - Tx = thoracocentesis, then aim to slow down the return of pleural effusion by treating the CHF: pimobendan, Ace-I, diuretics
2. Pericardial Disease
   - pericardial effusion –> cardiac tamponade –> ascites, pleural effusion
   - the pleural effusion will resolve with pericardectomy
   - presence of ascites = chronic, better prognosis than acute
   - can also develop pleural effusion with constrictive pericarditis
3. Cancer
   - treatment pending the cancer
   - not all cancer will exfoliate will in the fluid
   - mesothelioma = challenging

Question 6

What’s the definition of hemothorax?

Answer 6

hemorrhagic effusion with PCV > 20% or > 50% peripheral PCV

Question 7

What are the 3 causes of pneumothorax?

Answer 7

1. spontaneous - in dogs, should prompt surgical exploration
2. traumatic - if from blunt, trauma, will resolve with time. Penetrating wounds will need Sx
3. iatrogenic

Question 8

What are the 2 types of spontaneous pneumothorax?

Answer 8

1. Primary - no underlying pulmonary disease (ex. ruptured bullae). Very rare in cats, more common in dogs. Needs surgical exploration for correction. Really important to ddx between blunt trauma
2. Secondary - due to underlying pulmonary disease (ex. feline asthma, neoplasia, PTE). Treatment depends on severity and underlying cause.