Lab case 39 – Interpretation

A 34 year old female with a large right sided pleural effusion


1. Clinical Examination:

Inspection – signs of respiratory distress (tachypnoea, accessory muscle use, difficulty in speaking full sentences), asymmetrical chest expansion

Palpation – Reduced chest expansion, tracheal deviation to the opposite side, reduced fremitus

Percussion – stony dullness

Auscultation – reduced breath sounds and vocal resonance, egophony, pleural rub

2. Patient has an exudate, using Light’s criteria:

Pleural:serum  LDH > 0.6

Pleural LDH > 2/3 of the upper limit of normal serum LDH

Pleural:serum protein > 0.5

with predominance of eosinophils (which is usually non specific) and negative gram stain.

pH and glucose is not given

3. Causes:

Pancreatic pseudocyst

Infection – parapneumonic, TB



Connective Tissue disease – Rheumatoid arthritis, SLE

4. Indications for Drainage:

Significant respiratory distress

pH < 7.2

Purulent fluid

WCC > 50 000, (PMN > 1000)

Glucose < 3 mmol/l

LDH >1000 IU/ml

Positive culture