Pleural Effusion

Question 1

what is a pleural effusion?

Answer 1

collection of fluid in the pleural cavity (between lung and chest wall)

can result from pleural, pulmonary or extrapulmonary diseases

can be exudative or transudative

Question 2

exudative pleural effusion

Answer 2

high protein count >3g/dL (>35g/L)

causes are related to inflamamtion which results in protein leaking out of the tissue into the pleural space (ex= move out)

• lung cancer
• pneumonia
• RA
• tuberculosis
  subdiaphragmatic- pancreatitis
  trauma- haemathorax, chylothorax

Question 3

transudative pleural effusion

Answer 3

relatively lower protein count <3g/dL

fluid moving ACROSS into the pleural space (trans=move across/shifting) as a result of increased hydrostatic pressure of decreased oncotic pressure

congestive cardiac failure (bilateral effusions)
hypoalbuminaemia
hypothyroidism
meig's syndrome (R side pleural effusion with ovarian malignancy)
LVF
cirrhosis
PE
myxodedema
sarcoidosis
peritoneal dialysis

Question 4

what are the symptoms of a pleural effusion?

Answer 4

progressive SOB
pleuritic pain
symptoms of an underlying condition

Shortness of breath
Dullness to percussion over the effusion
Reduced breath sounds
Tracheal deviation away from the effusion if it is massive
reduced chest wall movements

decreased tactile / vocal fremitus

Question 5

investigations for pleural effusion

Answer 5

bedside: ABG. sputum for MC+S
bloods: FBC, clotting, LFT, U+E, CRP

imaging:

1. ultrasound
2. CXR

blunting of costophrenic angle
fluid in lung fissures
meniscus (curving upwards)
tracheal and mediastinal deviation

3. CT to detect pleural fluid seperation and differentiate between benign/malignant cause
4. diagnostic aspirate of effusion. sample of pleural fluid by aspiration / chest drain (US guided)
   - protein count
   - cell count
   - pH
   - glucose
   - LDH
   - microbiology testing
   - colour
   - odour

Question 6

treatment of pleural effusion

Answer 6

1. conservative management (small resolve without tx) if CHF diuretics, physiology, echo, therapeutics, thoracocenteiss, o2

if infecitve- antibiotic (IV cefurxime + IV metronidazole)

2. pleural aspiration (larger) (stick needle to aspirate fluid, can temp relieve but can recur)
3. chest drain (if recurring)

Question 7

what is empyema?

Answer 7

infected pleural effusion

e.g. improving pneumonia but new / ongoing fever

pleural aspiration
pus and acidic pH <7.2, low glucose, high LDH

treatment of empyema: chest drain and antibiotics

Question 8

what is the light’s criteria?

Answer 8

protein levels in a transudate is <25g/L nd protein levels in exudate is >35g/L

however if the protein is 23-25g/L (if difficult to interpret as close to cut off value)

exudate if:

1. pleural fluid protein level: serum protein level exceeds 0.5 (i.e it is exudate if the fluid protein level is greater than half the serum protein level)
2. pleural fluid LDH exceeds 0.6 (if the fluid LDh level is greater than 0.6 times the measured serum LDH level)
3. pleural fluid LDH exceeds 2/3 x upper limit of normal for serum LDH (if the fluid LDH is greater than 2/3 the upper limit of norma for serum LDH)

transudate low S.G, low protein

exudate high s.G
protein 1.5g/dl

Question 9

meig’s syndrome

Answer 9

right sided ovarian mass and transudate pleural effusion.

ca-125 (ovarian tumor)

Question 10

empyema

Answer 10

collection of pus in the pleural cavity and life threatening after disseminated bacteraemia, trauma or complication of pneumonia

investigation: pleural aspirate

Question 11

macroscopic inspection of pleural effusion

Answer 11

colour: clear/blood stained/ odour

if <30 >30 unclear then use light’s criteria

cytology: 
prtoein
LDH
pH
organisms

CT thorax
CT USS
video associated thorascopic surgery

Question 12

which bronchus is a foreign body most likely to enter?

Answer 12

the right inferior locar bronchus (it is shorter, wider and at a shallower angle)