25/01/2025
Ascites refers to the abnormal accumulation of fluid in the peritoneal cavity. It is usually a manifestation of an underlying condition. Here’s an overview:
Clinical Overview of Ascites
Etiology
1. Portal Hypertension (80% of cases)
• Cirrhosis (most common cause)
• Hepatic venous outflow obstruction (e.g., Budd-Chiari syndrome)
• Portal vein thrombosis
2. Malignancy
• Peritoneal carcinomatosis (e.g., ovarian, gastric, or pancreatic cancers)
• Hepatocellular carcinoma
3. Infections
• Tuberculous peritonitis
4. Cardiac Causes
• Right-sided heart failure
• Constrictive pericarditis
5. Other Causes
• Hypoalbuminemia (e.g., nephrotic syndrome, protein-losing enteropathy)
• Pancreatic ascites (due to pancreatic duct rupture)
• Chylous ascites (lymphatic obstruction)
Pathophysiology
• Cirrhosis: Portal hypertension leads to increased hydrostatic pressure in the splanchnic circulation, hypoalbuminemia, and activation of the renin-angiotensin-aldosterone system, resulting in fluid accumulation.
• Infections/Malignancy: Inflammation or obstruction increases vascular permeability, leading to fluid exudation into the peritoneal cavity.
Clinical Features
• Symptoms:
• Progressive abdominal distension
• Weight gain
• Dyspnea (due to diaphragmatic elevation)
• Abdominal discomfort
• Signs:
• Shifting dullness
• Fluid wave
• Everted umbilicus (tense ascites)
• Signs of underlying etiology:
• Spider nevi, jaundice, palmar erythema (cirrhosis)
• Cachexia or abdominal mass (malignancy)
• Fever and abdominal pain (infection)
Diagnostic Evaluation
1. Abdominal Paracentesis (Diagnostic Tap):
• Appearance of fluid:
• Clear/yellow: Transudative (e.g., cirrhosis)
• Cloudy: Infection (e.g., spontaneous bacterial peritonitis)
• Bloody: Malignancy/trauma
• Serum-Ascitic Albumin Gradient (SAAG):
• SAAG ≥ 1.1 g/dL: Portal hypertension (e.g., cirrhosis, cardiac ascites)
• SAAG < 1.1 g/dL: Non-portal hypertension causes (e.g., malignancy, infection)
• Other Tests:
• Total protein, cell count, Gram stain, culture, cytology
2. Imaging:
• Ultrasound: Most sensitive for detecting small volumes of fluid
• CT abdomen: Identifies underlying malignancy or other causes
3. Liver function tests (LFTs), coagulation profile
Management
1. General Measures:
• Sodium restriction (
