From the Guidelines
Ascites in pediatric patients is primarily caused by liver disease, including cirrhosis, biliary atresia, and other genetic metabolic disorders, as well as congenital infections and mitochondrial disorders. The causes of ascites in pediatric patients can be multifaceted, involving various conditions that lead to fluid accumulation in the peritoneal cavity. According to the most recent guidance by the American Association for the Study of Liver Diseases 1, the underlying causes of cirrhosis in children with ascites include biliary atresia, primary sclerosing cholangitis, autoimmune hepatitis, cholestatic genetic disorders, Wilson disease, alpha-1 antitrypsin deficiency, and many other genetic metabolic disorders. Some key points to consider in the causes of ascites in pediatric patients include:
- Liver disease, such as cirrhosis, hepatitis, or biliary atresia, is a significant contributor to ascites in pediatric patients, often resulting from portal hypertension which increases hydrostatic pressure in the portal venous system, forcing fluid into the peritoneal space 1.
- Congenital infections, mitochondrial disorders, tyrosinemia, and biliary atresia are also notable causes of ascites in newborns and infants 1.
- Other conditions such as heart failure, nephrotic syndrome, protein-losing enteropathy, and malnutrition can also contribute to the development of ascites in pediatric patients. It is essential to identify and treat the underlying cause of ascites in pediatric patients, as it can significantly impact a child's respiratory function, nutrition, and overall development. Management may involve diuretics, sodium restriction, albumin infusions, or paracentesis for severe cases, with diuretic therapy commonly commenced with spironolactone or spironolactone and furosemide in combination 1.
From the Research
Causes of Ascites in Pediatric Patients
The causes of ascites in pediatric patients can be categorized into several broad groups, including:
- Hepatic disorders, such as chronic liver disease and cirrhosis, which are the most common causes of ascites in children 2, 3
- Renal disorders, which can lead to fluid retention and ascites 3
- Cardiac disorders, which can cause fluid buildup in the peritoneal cavity 3
- Other causes, such as portal hypertension and sodium and fluid retention, which are key factors in the pathophysiology of ascites 4, 3
Key Factors in the Pathophysiology of Ascites
The peripheral arterial vasodilation hypothesis is the most accepted mechanism for inappropriate sodium retention and formation of ascites 4, 3. This hypothesis suggests that vasodilation of the peripheral arteries leads to a decrease in effective arterial blood volume, which in turn triggers the renin-angiotensin-aldosterone system and causes sodium and water retention.
Classification of Ascites
Ascites can be classified into two main categories: portal hypertensive and non-portal hypertensive, based on the serum-ascites albumin gradient (SAAG) 4, 3. A SAAG greater than 1.1 g/dL indicates portal hypertensive ascites, while a SAAG less than 1.1 g/dL indicates non-portal hypertensive ascites.
Complications of Ascites
The most important complications of ascites are spontaneous bacterial peritonitis (SBP) and hepatorenal syndrome 4, 5. SBP is a serious infection that can occur in patients with ascites, and is characterized by a neutrophil count greater than 250 cells/mm3 in the ascitic fluid 4, 3. Hepatorenal syndrome is a type of kidney failure that can occur in patients with advanced liver disease and ascites 5.