Pleural and Peritoneal fluid

Question 1

How much pleural effusion to see on CXR

Answer 1

300ml

Question 2

Transudate Vs exudate

Diagnosis and causes

Answer 2

Exudate over 30g/L of protein
Transudate less than 30g/L of protein

Unilateral more likely to be exudate

Exudate: infection, malignancy, PE/Infarction, TB, Rheumatoid disease, Acute pancreatitis

Transudate: Cardiac failure, Liver failure (low albumin), Nephrotic syndrome, Malnutrition, Hypothyroidism

Question 3

Colour of pleural aspirate and diagnosis:

• Straw
• Yellow
• Blood stained
• Frank blood
• Pus
• Food debris

Answer 3

• Straw: Normal
• Yellow: Infection
• Blood stained: Trauma, Malignancy
• Frank blood: Mesothelioma, Trauma, Malig
• Pus: Empyema
• Food debris: Oesophageal rupture

Question 4

Role of paracentesis

Answer 4

Charecterise disease causing ascites, detect infection

Therapeutic in large collections

Question 5

Exudate Vs Transudate in Ascites

Differentiation

Causes

Answer 5

Exudate: over 25g/L protein
Transudate: under 25g/L protein

SAAG test is better way of differentiating

Transudate: Cirrhosis (portal HTN), cardia failure (R-sided), Hypoalbuminaemia, Nephrotic syndrome

Exudate: Intraperitoneal malignancy (primary or secondary), Infection including TB, Pancreatitis, Hypothyroidism

Question 6

Diagnosing SBP

Answer 6

WCC (Neutrophils) + clinical symptoms

If multiple organsms seen on Gram staining then consider alternative cause e.g. perforated bowel

Question 7

Detecting malignancy from peritoneal fluid

Answer 7

Low glucose

Cytology