Ascites - Approach

• Symptoms: weight gain, lower extremity edema (negative LR 0.1)

• Pathophysiology:
• Elevated hydrostatic pressures (SAAG >1.1)
• Normal JVP: cirrhosis (80%), alcoholic hepatitis, IVC obstruction, Budd-Chiari, portal vein thrombosis
• Elevated JVP: heart failure, constrictive pericarditis, pulmonary hypertension
• SAAG <1.1
• Decreased oncotic pressure (ascitic total protein <2.5 g/dL): protein losing enteropathy, nephrotic syndrome, malnutrition
• Increased permeability (ascitic total protein >2.5 g/dL): malignancy (8%), infection (TB, secondary peritonitis), serositis, pancreatitis
• Diagnosis
• Physical exam: shifting dullness (LR 2.7) and fluid wave (LR 6.0) are most helpful maneuvers
• Gold standard for diagnosis is ultrasound, which can detect as little as 100cc
• Paracentesis, with following:
• Cell count: >250 PMN/mm3 indicates spontaneous bacterial peritonitis
• Serum albumin ascites gradient (Serum albumin less ascitic albumin
• Total protein: when SAAG is >1.1, protein >2.5 mg/dL suggests cardiac ascites, <1 mg/dL increases risk of SBP
• o    When considering TB:
• AFB smear very insensitive
• AFB culture: 75% sensitive when one liter cultured
• Adenosine deaminase not useful (falsely depressed in cirrhosis)
• Often requires peritoneoscopy and biopsy
• When considering malignancy:
• Cytology: 50cc typically sufficient if coordinated with lab for prompt processing (sensitivity increases from 83% to 97% if send 3 samples)

(Christopher Woo MD, 5/10/11)