Pleural Effusions

Question 1

Thoracentesis

Answer 1

• Insert needle b/t ribs into pleural space to sample pleural effusions
• Done in all patients that CHF is NOT the obvious cause
• Risk: pneumothorax or hemothorax
• Contraindicated if increased risk of bleeding or only 1 lung

Question 2

Definition of exudate

Answer 2

• Meets at least one of Light’s criteria
  1. Pleural protein to serum protein ratio>0.5
  2. pleural LDH to serum LDH ratio>0.6
  3. Pleural LDH > 2/3 upper limit of normal for serum LDH
• Caused by many things: pneumonia, malignancy, and PE most common

Question 3

Define transudate

Answer 3

• Doesn’t meet ANY of light’s criteria
• Usually due to increased pulmonary capillary pressure due to heart failure
• Also caused by deceased plasma oncotic pressure
  
  • Hypoalbuminemia from cirrhosis
  • Nephrotic syndrome

Question 4

Pleuritic chest pain

Answer 4

• Sharp stabbing pain

- Worsened w/ inspiration or cough

Question 5

Loculated

Answer 5

• Fluid collected agains chest wall and doesn’t move
• Doesn’t layer w/ gravity or position change
• Most common in intesne pleural inflammation
  
  • Pneumonia, TB, hemothorax

Question 6

Empyema

Answer 6

• Due to pneumonia
• Also called parapneumonic
• Similar to abscess
• Requires drainage
• Characteristics: acidic pH, low glucose, high LDL, visible pus

Question 7

Tube Thoracostamy

Answer 7

-Placing tube in chest wall b/t ribs to drain empyema, blood or air

Question 8

Sclerosant

Answer 8

• Chemical that cause inflammatory reaction in pleural space
• Obliterates pleural space so no fluid can return
• Antibiotics or powders

Question 9

Role of pH in effusions

Answer 9

• pH <7.2 suggests complicated effusion/empyema

- also seen in malignancy or TB

Question 10

Glucose levels in effusion

Answer 10

• Normally same as serum
• Low is associated w/ same conditions as low pH
• glucose of 0 only seen in empyema or rheumatoid arthritis

Question 11

Effusion with >10% eosinophils

Answer 11

• pneumothorax
• hemothorax
• Benign asbestos effusion

Question 12

Effusions with >50% lymphocytes

Answer 12

• Malignancy
• TB
• PE
• Post-CABG

Question 13

Effusion with >90% lymphocytes

Answer 13

-TB or lymphoma

Question 14

Effusion with >50% neutrophils

Answer 14

• parapneumonic effusion
• PE
• Intrabdominal disease
• Very rarely TB or cancer

Question 15

Scarcity of mesothelial cells in effusion

Answer 15

• Normally present in pleural fluid as cells are exfoliated
• Paucity indicates:
• TB
• Empyema
• Chronic cancer
• Due to intense inflammation limiting shedding

Question 16

Effusion with Adenosine Deaminase (ADA) >40U/L

Answer 16

• TB 90%
• Empyema 60%
• Parapneumonic 30%
• Malignancy 5%
• RA

Question 17

Interferon and effusions

Answer 17

-Identifies TB effusion

Question 18

Amylase increase and Effusions

Answer 18

-Increased due to malignancy, pancreatic disease, or esophageal rupture

Question 19

Cholesterol levels in effusion

Answer 19

> 45-60 mg/dL suggests exudate

Question 20

NT-pro BNP levels

Answer 20

> 1500 mg/dL suggests heart failure

Question 21

Pathophysiology or Effusion

Answer 21

1. Increased fluid formation
   - Increased capillary pressure from heart failure
   - Decreased capillary oncotic pressure from liver failure, nephrotic syndrome or malnutrition
   - Ascites from cirrhosis can move up to pleura (hepatic hydrothorax)
   - Transudative
2. Fluid removal limited by obstruction
   - Damage to capillaries
   - Infection from pneumonia or TB
   - Malignancy
   - Trauma
   - Systemic disease such as lupus

Question 22

Effusion presentation

Answer 22

• Decreased breath sounds
• Decreased tactile fremitus
• Decreased voice transmission
• In large effusions, trachea may deviate from affected side
• CXR shows costophrenic angle blunting
  
  • Lat. decubitus position shows free fluid