Ascites is the abnormal accumulation of fluid within the abdominal cavity. It is a condition with a wide range of causes. Ascites develops most frequently as a result of liver disease. It can also be seen in people who have cancer, kidney disease, pancreatic disease, heart disease, and other conditions.
Mechanisms in the body leading to ascites are complex and not completely understood. The accumulation of fluid in the abdominal cavity can be associated with portal hypertension. This means there is an increased blood pressure in the veins draining the intestines and spleen toward the liver. The higher pressure can be caused by liver damage. It can also be caused by impaired drainage in the lymph system. This system takes excess fluid and particles away from the liver.Low levels of albumin and other proteins in the blood also contribute to ascites. The force that holds plasma water within the blood vessels is reduced. Plasma water is lost into the abdominal cavity. Albumin in the ascitic fluid pulls yet more fluid across into this cavity.Blood flow to the kidneys might be reduced. This leads to increased secretion of the hormone aldosterone. This increase causes the kidneys to retain salt and water. Urinary output is decreased, and fluid is retained. In some cases, kidney disease contributes to impaired elimination of salt and water.Fluid may leak from capillaries, the pancreas, or the lymph system. Capillary fluid leakage can be caused by inflammation or infection.
All of these events may lead to a large volume of abdominal ascites. An adult with cirrhosis of the liver may have as much as 10 to 12 liters (about 10-12 quarts) of fluid in the abdominal cavity.
Depending on the amount of ascites and the cause, there may be no symptoms at all. Some of the common symptoms include: abdominal painchanges in bowel functiondifficulty breathing, especially when trying to take deep breathsdifficulty walkingfatiguefeeling full after eating only small amounts of foodincreasing abdominal girthlow back painshortness of breath
Ascites is most often a result of liver disease, including the following: alcoholic liver diseasechronic hepatitis from viruses, medications, or the person's immune systemcirrhosis, which is permanent scarring of the liverliver cancersudden liver failure, which can be due to infection or drug reactions
Other common causes of ascites include the following: bile leaking into the abdomenblood or fluid leaking from the blood vessels into the abdomencancercertain kidney conditionscongestive heart failure, a condition in which the weakened heart fails to pump blood effectivelyconstrictive pericarditis, which is a tightening of the lining around the heartgastrointestinal diseases that cause a loss of protein, such as inflammatory bowel diseaseinflammation of the lining of the abdomen, known as peritonitisobstruction in the inferior vena cava, one of the largest veins in the bodypancreatic fluid leaking into the abdomensevere malnutritiontuberculosis that has infected the peritoneumtumors on the lining of the abdomen
Some cases of ascites can be prevented. For example, alcoholic cirrhosis can be prevented by avoiding excessive drinking of alcohol. Effective treatment of congestive heart failure can prevent ascites from that cause.
The diagnosis of ascites begins with a medical history and physical exam. The healthcare provider may be able to detect fluid in the abdomen. Special X-ray tests, such as an ultrasound or CT scan, are also commonly used to diagnose ascites and help determine the cause.
A diagnostic test, called paracentesis involves the insertion of a needle through the skin and into the abdominal cavity. The needle is used to withdraw fluid. Testing the fluid helps to determine the cause of the ascites. For example, an elevated white blood cell count, or WBC, may indicate an infection.
Long-term effects of ascites can include the following: difficulty breathingdifficulty walking and performing daily activitiesgastrointestinal problemsheart failurekidney failureinfection of the ascites fluidmalnutritionsleep disorders
Ascites is not contagious and poses no risk to others.
Treatment of ascites includes treatment of the underlying disorder. Some of the general treatment guidelines followed for ascites itself are as follows: bed rest to improve kidney functiona diet limited to 2 grams of sodium a dayfluid restricted to 1 liter a dayhospitalization to monitor the daily weight and salt balance
Diuretics, also called water pills, may also be used to treat ascites. These medications help the body excrete extra water through the kidneys. Common diuretics include spironolactone (i.e., Aldactone), amiloride (i.e., Midamor), and triamterene (i.e., Dtrebuyn(. If these are not effective, other diuretics may be used, including furosemide (i.e., Lasix), hydrocholorothiazide (HCTZ, i.e., Esidrix, HydroDiuril, Microzide, Oretic), and ethacrynic acid (i.e., Edecrin).
Some people with massive ascites may need a paracentesis to remove excess fluid. A needle is inserted into the abdominal cavity, and extra fluid is drained out.
Most people respond to these measures. About 10% to 15% are resistant and require other methods to control the ascites.
Other individuals may need a transjugular intrahepatic portosystemic shunt, also called TIPS. This is a mesh catheter tube that is passed through the skin of the neck and into the jugular vein. The catheter is then advanced into the liver. It is pushed into the portal vein, which drains into the liver. The shunt reduces pressure and ascites formation. In some cases, depending on the underlying cause, a liver transplant may be needed
Side effects of diuretics can include the following: dehydrationhigh or low potassium levels in the bloodkidney failure
Removal of large volumes of fluid using paracentesis may cause the following conditions: decreased kidney functionlow blood pressure, called hypotensionshock
Some of the side effects that shunting procedures can cause include: abnormal blood clotting that may result in bleedingchange in mental functioning or level of consciousnessclotting of the shuntinfection
In most cases, treatment of ascites is lifelong.
Ascites is monitored with lab tests and regular visits to the healthcare provider. Any new or worsening symptoms should be reported to the provider.