Ascites is the abnormal accumulation of fluid in the peritoneal cavity, the space between the abdominal organs and the abdominal wall. It is a common complication of various medical conditions, particularly liver disease.

Causes

Ascites can result from several underlying conditions, broadly categorized into hepatic and non-hepatic causes:

Hepatic Causes

• Cirrhosis: The most common cause of ascites, accounting for approximately 80% of cases. Cirrhosis leads to portal hypertension and reduced albumin production, causing fluid to accumulate.
• Severe alcoholic hepatitis: Can lead to ascites even without cirrhosis.
• Hepatic vein obstruction (Budd-Chiari syndrome): Blocks blood flow out of the liver.
• Portal vein thrombosis: Rarely causes ascites unless accompanied by liver damage.

Non-Hepatic Causes

• Malignancy: Cancers such as those of the liver, pancreas, colon, ovaries, or stomach can lead to fluid buildup in the abdomen.
• Heart failure: Causes systemic venous congestion leading to fluid leakage.
• Nephrotic syndrome: Severe protein loss in urine reduces oncotic pressure.
• Infectious peritonitis: Bacterial or fungal infections can cause inflammation and fluid accumulation.
• Pancreatitis: Inflammation of the pancreas may lead to ascitic fluid formation.

Symptoms

The symptoms of ascites depend on the volume of fluid and underlying cause:

Mild Ascites

• Often asymptomatic
• May be detected incidentally during imaging studies

Moderate to Severe Ascites

• Abdominal distension and bloating
• Weight gain
• Discomfort or pain in the abdomen
• Shortness of breath due to diaphragm compression
• Early satiety (feeling full quickly)
• Swelling in the lower extremities (edema)

Complications

• Spontaneous bacterial peritonitis (SBP): Infection of the ascitic fluid causing fever, abdominal pain, and worsening symptoms.
• Hepatorenal syndrome (HRS): Kidney failure associated with severe liver disease.

Diagnosis

Diagnosis of ascites involves a combination of clinical evaluation and diagnostic tests:

• Physical Examination:
  • Bulging flanks
  • Shifting dullness on percussion
  • Fluid wave test
• Imaging Studies:
  • Ultrasound or CT scan confirms the presence of fluid and evaluates its extent.
• Paracentesis:
  • A needle is used to withdraw ascitic fluid for analysis.
  • Tests include cell count, albumin levels (serum-ascitic albumin gradient or SAAG), culture, and cytology to determine the cause.
• Laboratory Tests:
  • Liver function tests
  • Kidney function tests
  • Coagulation profile

Treatment

Treatment for ascites focuses on addressing the underlying cause and managing symptoms:

• Lifestyle Modifications:
  • Sodium restriction (< 2 g/day) to reduce fluid retention.
  • Avoiding alcohol in cases related to liver disease.
• Medications:
  • Diuretics such as spironolactone (preferred) and furosemide to promote fluid excretion.
  • Antibiotics for spontaneous bacterial peritonitis (e.g., cefotaxime).
• Paracentesis:
  • Therapeutic paracentesis is performed to remove large volumes of fluid in cases of severe ascites causing discomfort or respiratory issues.
• Surgical Interventions:
  • Transjugular intrahepatic portosystemic shunt (TIPS): A procedure that reduces portal hypertension by creating a connection between the portal vein and hepatic vein.
  • Liver transplantation for end-stage liver disease with refractory ascites.

Prognosis

The prognosis for patients with ascites depends on its underlying cause. Ascites related to cirrhosis often indicates advanced liver disease with a poor long-term prognosis unless treated with liver transplantation. Early diagnosis and appropriate management are critical in improving outcomes and preventing complications.