Connective Tissue Fluid

This section will evaluate fluid aspirated

• Pleural fluid

• Pericardial fluid

• Ascitic fluid

• Joint fluid

• Perimass fluid/ collection ?abscess ?cancer

Ascitic Fluid

Most common cause: liver cirrhosis (transudate)

Transudate

Criteria: protein < 30

• Hepatic cirrhosis & Budd Chiari Syndrome

• Heart failure (right sided)

• Nephrotic syndrome (hypoalbuminaemia) & acute nephritis

Exudate: protein > 30

• Infection: Tb, SBP

• Inflammation: vasculitis, pancreatitis

• Malignancy: GI primary or metastatic

SAAG

Marker of portal pressure, particularly looking if the cause is from portal hypertension. 

SAG < 11: malignancy, infection & nephrotic syndrome

SAG > 11: portal hypertension

Why is SAG < 11: nephrotic syndrome when SAG i

Common misconception that SAG is a marker of exudate vs transudate. This is not the case. Protein dictates transudate vs exudate. SAAG is a marker of portal pressure, hence nephrotic syndrome has a low SAG despite being 

Written in 2025. 

References & Resources

1. https://geekymedics.com/ascitic-fluid-analysis/