What is Ascites?
Ascites is an abnormal accumulation of fluid within the abdominal cavity. The fluid accumulates as a result of a chronic, progressive disease. It is most often associated with diseases involving the liver. The cause is poorly understood.
The large majority of individuals with ascites have cirrhosis of the liver, which can result from longstanding liver inflammation, infection, or alcohol abuse. Cirrhosis is a permanent scarring of the liver, which causes elevated pressure in the veins to the liver (portal hypertension). Ascites may then result. Severe congestive heart failure of the right ventricle can also cause ascites, perhaps also by increased venous pressure Ascites without portal hypertension can be caused by disease involvement of the inner lining of the abdomen (peritoneum). Ovarian cancer commonly spreads to the peritoneum, and ascites may be its first symptom. Tuberculosis can infect the peritoneum and result in ascites. Chronic renal failure (nephrotic syndrome, chronic glomerulonephritis) can also be associated with ascites. Individuals on dialysis (hemodialysis) can have ascites. Inflammation of the pancreas or gallbladder, with leakage of their secretions and contents into the abdomen, can cause ascites.
Other less frequent causes are diseases of the small intestine that cause protein to be chronically lost from the body. Severe underactivity of the thyroid gland (hypothyroidism) may rarely cause ascites. Chylous ascites, an accumulation of lymph in the abdomen, can occur when the lymph circulation becomes blocked by a tumor.
How is Ascites diagnosed?
- History is of abdominal distention, perhaps by noticing that a belt or clothes are becoming too tight. Pain is usually absent; but when pain is present, the location and character of the pain may lead to the diagnosis of the underlying cause. Individuals may note weight gain. Shortness of breath can be experienced with a large accumulation of ascites when it limits the space for the lungs to expand. Swelling may occur in other parts of the body, especially where gravity pulls the fluid, as to the ankles. A history of "yellow jaundice" might be reported. Most often they already know they have a chronic disease.
- Physical exam: The abdomen will be distended. Physical examination can detect the presence of free flowing fluid in the abdomen. Signs of liver disease may be present, including abnormal veins on the abdomen and face, red palms and face, and jaundice. The person may appear chronically ill. The rate of breathing may be high. Distended neck veins could indicate heart failure. Fever, if present, could point to an infectious process.
- Tests: Blood tests may confirm infection, liver inflammation, kidney failure, pancreatitis, hypothyroidism, and certain types of cancer. Ultrasound imaging can quickly and easily identify the presence of ascites as well as give valuable information as to why the ascites might be present. CT scan is used to identify ascites and give detailed images of the organs in the abdomen. Withdrawing some of the ascites fluid with a needle through the abdominal wall (paracentesis) can give valuable information as to the composition of the fluid and indicate the direction in which to look for the cause.
How is Ascites treated?
Treatment of ascites must be directed at the underlying cause. Accurate diagnosis is therefore essential, as heart failure requires very different treatment than cancer. Frequently, the underlying cause is not reversible. Efforts to remove the fluid are useful for the individual's comfort. Diuretics can be used to help remove the excess fluid. Withdrawing large amounts of the fluid through a needle (therapeutic paracentesis) can be done. There are several surgical options such as to shunt ascites fluid into a large vein, to relieve portal hypertension if present, or to transplant the liver.
What might complicate it?
A serious complication is spontaneous bacterial peritonitis, where the ascitic fluid may become infected without any identifiable cause or reason. If ascites fluid is removed too rapidly, low blood pressure or shock can result. This may lead to kidney failure (hepatorenal syndrome) and is frequently fatal. Compromise of breathing can be a problem, especially for those with preexisting lung disease.
The predicted outcome depends on the underlying disease process. Since ascites is usually caused by a chronic, progressive disease process, the outlook is not good unless something can be done to correct the underlying disease.
Gastroenterologist, cardiologist, oncologist, infectious disease specialist, and endocrinologist.
Last updated 21 December 2011