Pleural effusion in critically ill patients and intensive care setting

Table 3 Some important pleural fluid analysis parameters and their relations to diagnosis[2,4,13]

Test result	Significance
Lymphocytes > 85%	Tuberculous pleural effusion, sarcoidosis, chronic rheumatoid pleurisy, yellow nail syndrome, chylothorax
Neutrophils > 10000 / µL	Para-pneumonic effusion, lupus pleuritis, acute pancreatitis
Neutrophils > 50000 / µL	Empyema
Red blood cells: pleural fluid to serum haematocrit value > 0.5	Haemothorax
Protein < 1 gm/dL	Peritoneal dialysis, central venous catheter migration, cerebrospinal fluid leakage into pleura
Protein > 4 gm/dL	Tuberculous pleural effusion
Eosinophils > 10%	Haemothorax, pulmonary infarction, benign asbestos pleurisy, coccidioidomycosis, drug-induced pleurisy, Churg-Strauss syndrome, polyarteritis nodosa, paragonimiasis and other parasites, Sarcoidosis, Hodgkin’s disease
Glucose: Pleural fluid to serum < 0.5	Complicated para-pneumonic effusion, chronic rheumatoid pleurisy, paragonimiasis, amoebic empyema, oesophageal rupture, tuberculous pleural effusion, lupus pleuritis, urinothorax
Glucose: pleural fluid to serum > 1	Peritoneal dialysis, central venous catheter migration
Lactate dehydrogenase > 1000 IU/L	Bacterial empyema, pancreatitis, pancreatic-pleural fistula, amoebic empyema, septic emboli, rheumatoid pleurisy
Pleural fluid pH < 7.3	Oesophageal rupture, chronic rheumatoid pleurisy, complicated para-pneumonic effusion, paragonimiasis, amoebic empyema, tuberculous pleural effusion, lupus pleuritis, urinothorax, pancreatic-pleural fistula
Elevated pleural fluid amylase	Oesophageal rupture, acute pancreatitis, pancreatic-pleural fistula
Creatinine: pleural fluid to serum > 1	Urinothorax
Cholesterol > 200 mg/dL	Pseudo-chylous effusion
Presence of chylomicrons	Chylothorax
Triglycerides > 110 mg/dL	Chylothorax, central venous catheter migration with lipid infusion
Beta 2 transferrin level elevated	Cerebro-spinal fluid leakage to pleura
Adenosine deaminase > 40 IU/dL with lymphocytosis.	Tuberculous pleural effusion