Lecture 4- CXR Effusions

Question 1

Pleural Fluid Production

Answer 1

• liquid originates from systemic vessels of pleural membrane (interstitial fluid)
• avg volume of pleural fluid is 8.4mL per hemithorax

Question 2

Pleural fluid absorption

Answer 2

• pleural liquid exits the pleural space via lymphatic stomata of parietal pleural
• pleural pressure is lower than interstiail pressure of either pleural tissues so liquid can move out of pleural space

Question 3

what can cause pleural fluid accumulation

Answer 3

• increased hydrostatic pressure (HF)
• decreased oncotic pressure (hypoalbuminemia)
• increased permeability (pneumoia)
• impaired lymph drainage (malignancy)
• movement of fluid into peritoneal space (ascites)

Question 4

define:
* pneumothorax
* hydrothorax
* hemothorax
* chylothorax
* pyothorax

Answer 4

• pleural: abnormal accumulation of fluid in pleural space
• hydro: noninflammatory collection of serous fluid
• hemo: blood accumulation
• chylo: lymph fluid
• pyo: infection

Question 5

transudative vs exudative effusion

Answer 5

• transudative: increased hydrostatic/decreased oncotic pressure
• exudative: increased vascular permeability (high protein)

Question 6

causes of transudative?

5

Answer 6

• CHF
• nephrotic syndrome
• cirrhosis
• hypoalbuminemia
• atelectasis

Question 7

causes of exudative

Answer 7

• malignancy
• infection/empyema
• trauma
• TB
• SLE
• dressler syndrome
• pancreatitis

Question 8

first place fluid accumulates?

Answer 8

subpulmonic location

Question 9

describe blunting of costophrenic angles w/ effusion

Answer 9

• takes 300 mL of fluid to blunt when lateral
• takes 75 mL of fluid to blunt the posterior costophrenic angle
• pleural thickening from fibrosis can blunt costophrenic angles

Question 10

why does mensicus sign happen?

Answer 10

• natural elastic recoil of lungs so the pleural fluid appears to rise higher along lateral aspect of thorax

Question 11

how does free flowing fluid look in following views:
* upright
* supine
* semi-recumbent
* decubitus

Answer 11

• upright: base of thoracic cavity
• supine: layer on post pleural space
• semi rec: triangular density of varying thickness
• decub: bandlike distribution along dependent side

Question 12

why would you use decubitus views

Answer 12

• confirm presence of pleural effusion
• detemine if it is free flowing
• “uncover” part of lung hidden by effusion

Question 13

components of complete opacification of hemithorax

Answer 13

• takes 2L of fluid to opacity entirely
• displacement of heart/trachea away from affected side
• can cause atelectasis
• difficult to evaluate lung w/ CXR, do CT

Question 14

Describe loculations

Answer 14

• adhesions in pleural space (empyema/hemothorax)
• not free flowing, will not change with position
• more often require chest tubes

Question 15

describe pseudotumors

Answer 15

• caused by heart failure
• loculated fluid commonly located in minor fissure
• lemon shaped

Question 16

Laminar Effusion

Answer 16

• type of pleural effusion
• fluid takes on a thin, band like density along lateral chest wall near costophrenic angle (usually will not blunt the angle)
• CHF most common cause

Question 17

hydropneumothorax

Answer 17

• presence of both air & fluid in thorax
• causes: trauma, surgery, thoracentesis, bronchopleural fistula
• loss of meniscoid shape (straight line)

Question 18

laterality causes:
* right
* left
* bilat
* nonspecific unilat

Answer 18

• r: ascite, RA
• l: pancreatitis, dressler syndrome
• bilat: CHF, SLE
• unilat, nonspecific: malignancy, TB, PE, pneumonia

Question 19

pleural effusion tx

Answer 19

• underlying condition: diuretics, diet control
• thoracentesis
• chest tube (if empyema)
• pleurodesis (recurrent)