Ascites in Children - An Overview

Introduction

Delicate and highly regulated hydrostatic and oncotic forces regulate blood and lymphatic flow to the splanchnic (organs present inside the abdominal cavity), portal (vascular network), and hepatic regions. Disturbances to the balance of these forces cause ascites. Children can develop ascites due to renal, cardiac, and hepatic causes. This article reviews information on ascites in children.

What Are Ascites in Children?

Ascites are the pathological collection of serous fluid within the peritoneal cavity. It is a frequent side effect of liver cirrhosis and a symptom of severe liver disease. Portal hypertension and sodium and fluid retention are essential factors for developing ascites in children. Children who have ascites are more likely to experience spontaneous bacterial peritonitis, which can lead to renal failure and mortality.

What Causes Ascites in Children?

Several factors can lead to the developing ascites in fetuses, neonates, or pediatric patients.

1. Congenital or Neonatal Ascites

   1. It is rare and commonly caused by intrauterine infections, metabolic disorders, cardiac structure and rhythm disorders, and rarely hematological or genitourinary disease.

   2. Liver and metabolic disorders cause 4 % of neonatal ascites.

   3. Rhesus hemolytic disease (destruction of red blood cells due to mother-fetus antibody incompatibility) is now a common cause of ascites due to the use of Anti-D immunoglobulin.

2. Ascites in Children

However, chronic liver disease and subsequent development of cirrhosis cause ascites development in children. Other causes include:

• Hepatic Non-cirrhotic (vascular abnormalities due to increase in hepatic blood pressure without inflammatory changes).

• Budd-Chiari syndrome (rare disease due to obstructed outflow in hepatic venous system).

• Congenital hepatic fibrosis.

• Bile duct trauma or perforation.

• Sinusoidal-obstruction syndrome (condition occurs due to blockage in hepatic veins).

• Non-hepatic Non-cirrhotic Ascites.

• Diseases of the peritoneum such as tuberculosis, cytomegalovirus, and Epstein-Barr virus.

• Intestinal causes include appendicitis, Crohn’s disease, eosinophilic enteropathy, intestinal atresia, meconium ileus, intestinal lymphangiectasia, intestinal malrotation or perforation, and pyloric duplication.

• Pancreatic conditions like acute pancreatitis and pancreatic pseudocyst.

• Inflammatory disorders like systemic lupus erythematosus and Henoch–Schonlein purpura.

• Metabolic disorders.

• Cardiac conditions like heart failure.

• Genitourinary disorders include nephrotic syndrome, obstructive uropathy, posterior urethral valves, bladder rupture, and ureterocele.

• Chylous ascites are caused due to thoracic duct trauma and ligation, intestinal lymphangiectasia, and total parenteral nutrition extravasation.

• Malignant conditions like lymphoma, Wilm’s tumor, germ cell tumors, and neuroblastoma.

• Pseudo-ascites are caused by celiac disease, cystic mesothelioma, omental cysts, and ovarian cysts.

• Other causes include abdominal trauma, hemoperitoneum, and ventriculoperitoneal shunt.

What Is the Mechanism of Ascites Development in Children?

1. Children can develop ascites secondary to cirrhosis because of splanchnic vasodilatation, portal hypertension, and hyperaldosteronism.

2. Ascites buildup and extracellular volume expansion are caused by sodium retention and portal hypertension.

3. Portal hypertension also elevates splanchnic capillary pressure, resulting in excess lymph formation.

Based on other theories, nitric oxide-mediated vasodilatation causes arterial blood volume reduction that activates the sympathetic renal nervous system, resulting in sodium retention in kidneys and antidiuretic hormone secretion.

What Are the Symptoms of Ascites in Children?

Peripheral edema is rare in children. Inappropriate weight gain is the first sign of ascites in children. The percussion in the flanks is dull. As fluid accumulation increase, the ascites becomes noticeable through inspection. At the supine position, the accumulated fluid appears as bulging flanks. Gradually, the abdomen becomes distended, and the umbilicus is everted due to raised abdominal pressure. Children with gross ascites have shiny skin with elevated intra-abdominal pressure leading to umbilical, inguinal, femoral, and incisional hernia.

How Are Ascites in Children Diagnosed?

A thorough physical examination and laboratory analysis of renal and liver disease are necessary. Laboratory tests must include measurement of transaminases, serum albumin, coagulation study, serum blood urea nitrogen, creatinine, urine analysis, and urinary sodium excretion.

The imaging study must include abdominal sonography to evaluate hepatic and biliary anatomy and liver vasculature and find evidence of portal hypertension. The volume and character of ascitic fluid can be visualized by imaging. However, diagnostic paracentesis is suggested for children with newly diagnosed or suspected complications of ascites. Percutaneous or trans jugular liver biopsy can help confirm the diagnosis.

How Are Ascites Treated in Children?

Medical and surgical management of ascites is dependent on the underlying cause. The treatment is selected based on the benefits outweighing the risks. The underlying problem must be treated to treat ascites caused by non-liver disease.

1. Nephrotic syndrome ascites respond to salt restriction and diuretics.

2. Ascites caused by tuberculosis improve with tuberculosis medication.

3. Lymphatic ascites following trauma or surgery require surgery.

4. Relief from pancreatic ascites can be obtained through endoscopic, open, or octreotide infusion surgery.

5. Mild-to-Moderate Ascites in Children

• It is treated with outpatient appointments if liver complications do not develop.

• Mild ascites need not be treated.

• For children with moderate ascites treatment is to achieve negative sodium balance through sodium restriction and improving sodium excretion with diuretics.

  • Sodium Restriction: It is a mainstay of treatment for patients with ascites. Fluid restriction is beneficial for children with hyponatremia. Daily salt intake can be half a teaspoon for older children and adolescents, but young children and infants must consume less than 1 gram of salt daily.

  • Diuretics: The medication is given as mono or dual therapy. Commonly used diuretics in children are spironolactone and furosemide. However, the drug must be used cautiously in children with renal impairment and electrolyte imbalance.

6. Large Ascites in Children

• It is necessary to perform a large-volume paracentesis with albumin infusion on children having large or unresponsive ascites. It removes 50 ml or more ascitic fluid per kilogram of body weight.

• Around 100 to 150 ml/kg (milliliter per kilogram) of body weight is removed safely.

• Additionally, children are given Frusemide daily with careful monitoring of electrolytes. However, large-volume paracentesis may be associated with post-paracentesis circulatory dysfunction (PPCD), a condition characterized by effective blood volume reduction. The complication is prevented with a slow infusion of albumin.

7. Management of Refractory Ascites

Earlier treatments do not work for this kind of ascites. Therefore, the following treatment is suggested:

1. Endovascular Shunts (prosthetic valves used for connecting two arterial sheaths to prevent fluid obstruction).

2. Trans jugular Intrahepatic Porto-Systemic Shunt (TIPS) and Peritoneal-Venous Shunt (PVS Shunt) are two methods for treating refractory ascites. However, these procedures could cause several complications and are executed when other treatment methods fail.

3. Liver Transplantation.

4. It is a life-saving procedure for all end-stage liver disease patients with refractory ascites. The treatment has an excellent prognosis if carried out before developing hepato-renal problems.

What Are the Complications of Ascites in Children?

Lack of or insufficient treatment causes the following complications:

• Significant lung restriction and compromised ventilation.

• Elevated infection risk.

• Gastrointestinal hemorrhage.

• Encephalopathy.

• Renal failure.

• Death.

Conclusion

Pediatric ascites develop when fluid builds up within the abdomen. The presenting symptoms for children with ascites are abdomen swelling, stomach pain, reduced appetite, and inappropriate weight gain. Renal, heart, hepatic, and pancreatic disorders are common causes of pediatric ascites. Although several treatments are available, it should be based on analyzing the benefits and risks.