Pleural Problems

Question 1

What is a pleural effusion?

Answer 1

Accumulation of fluid in the pleural space.

Question 2

How much pleural fluid is there normally?

What is it like?

Answer 2

<15ml

Clear, serous fluid, few cells.

Question 3

How much fluid would you need in a pleural effusion to be able to diagnose it clinically easily?

Answer 3

> 500ml

Question 4

What features would you see on CXR that may indicate a pleural effusion?

Answer 4

Blunting of the costophrenic angle

Question 5

What are the clinical features of pleural effusion?

Answer 5

• SOB
• Dry cough
• Pleuritic chest pain due to pleural inflammation
• Reffered pain to shoulder or abdomen
• Chest heaviness

Question 6

What clinical signs would you see on examination in a pleural effusion?

Answer 6

• Reduced chest expansion
• Quiet breath sounds
• Decreased tactile vocal cremates
• Stony dull percussion
• Bronchial breathing above fluid level.

Question 7

What is the physiological principle that explains why a pleural effusion would arise?

Answer 7

Arises when balance between pleural fluid production and absorption has been disturbed.

Question 8

List mechanisms of pleural effusions?

Answer 8

• Increased hydrostatic pressure
• Decreased osmotic pressure
• Increased vascular permeability
• Decreased lymphatic drainage
• Increased intra-pleural negative pressure.

Question 9

How would you investigate a pleural effusion?

Answer 9

CXR 
Pleural fluid sample 
CT chest 
Biopsy 
Thoracoscopy

Question 10

What could cause a unilateral pleural effusion?

Answer 10

• Infection: Always consider sepsis
• Breast/gynae malignancy
• Asbestos history
• TB
• Liver disease
• Cardiac failure

Question 11

What is the difference between a transudate and exuded pleural effusion and what causes them?

Answer 11

Transudate:

• Either less proteins in the blood or in congestive HF.
• In HF there is increased pressure in the hear and blood backs up to the lungs causing an increased in hydrostatic pressure. Fluid leaks out and causes a pleural effusion.

Exudate:

• Normally inflammatory.
• In inflammation vessels are dilated and endothelial cells are more spaced out, therefore fluid AND proteins leak out.

Question 12

What tests must be done through pleural fluid sampling?

Answer 12

• 100ml to cytology
• Biochemistry for LDH, glucose, proteins
• Microbiology for TB culture (also send blood culture if empyema suspected)

Question 13

How is pleural fluid sampled?

Answer 13

Under ultrasound guidance
Remove 1L if symptomatic then stop
DO NOT drain to dryness

Question 14

How much protein is in a transudate vs exudate effusion?

Answer 14

T: <30g/L
E: >30g/L

Question 15

How does serum LDH compare in transudate vs exudate effusion?

Answer 15

T: LDH <2/3rds of upper limit of normal.
E: >2/3rd of upper limit of normal.

Question 16

Are transudates/exudates normally bilateral or unilateral?

Answer 16

T: Often bilateral
E: Usually unilateral

Question 17

Describe the appearance of transudate pleural fluid vs. exudate pleural fluid?

Answer 17

T: clear usually
E: Can be clear, cloudy or blood stained.

Question 18

List causes of transudate pleural effusions?

Answer 18

Cardiac failure
Hepatic cirrhosis
Nephrotic syndrome
Hypoalbulminaemia

Question 19

List causes of exudate pleural effusions?

Answer 19

Bacterial pneumonia
Malignancy
Mesothelioma
TB

Question 20

What is a medical thoracoscopy?

Answer 20

An investigation to examine parietal pleura, visceral pleura and diaphragm with a thoracoscope.

Allows direct visualization of pleura, biopsies to be performed, and therapeutic manouvers to be performed e.g. pleural drainage or pleurodesis.

Question 21

Describe how a thoracoscopy is performed?

Answer 21

• Give oramorph/atropine
• Patient in lateral decubitus position
• Spot marked with ultrasound
• Local anesthetic e.g. Lidocaine
• Creation of pneumothorax
• Blunt dissection and port inserted
• Drainage of fluid with suction catheter
• Inspection of pleural surface
• Biopsies x10
• Talc pleurodesis if clearly malignant
• Size 24-28 chest drain - removed once lung re expanded.

Question 22

What is the name for cancer of the pleura?

Answer 22

Mesothelioma

Question 23

Where do metastases to the pleura normally come from?

Answer 23

Breast/ovary

Also bowel, renal, lymphoma

Question 24

What % of pneumonias has an associated effusion?

Answer 24

50%

Question 25

Describe results seen in a complex parapneumonic infection effusion?
(pH, LDH, glucose, ultrasound report)

Answer 25

• pH: <7.2
• LDH: >1000
• Glucose <2.2
• loculated on ultrasound

Question 26

What is empyema?

Answer 26

Collection of pus in the pleural cavity usually due to bacterial infection.

Question 27

How is empyema managed?

Answer 27

• Small bore chest drain (12-16F) - larger drains are more painful and not more effective
• Frequent sterile saline flushes
• IV antibiotics
• DVT prophylaxis
• Fibrinolytics e.g. streptokinase, DNAase and alteplase.