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abdominal dropsy, hydroperitoneum
Ascites is the abnormal accumulation of fluid within the abdominal or peritoneal cavity. It may be the result of non-cancerous or benign disease. Ascites may also be caused by cancer, which is called malignant ascites.
What is going on in the body?
Ascites is a common clinical finding that has a wide range of causes.
There are a number of factors that can lead to ascites:
What are the signs and symptoms of the condition?
- increased pressure in the veins that lead to or drain the liver. This is called increased hydrostatic pressure. The increased pressure causes fluid to leak out of the veins and accumulate in the abdomen. When there is increased pressure in the veins, there can also be increased pressure in the lymph circulation near the liver. The lymph circulation is a special drainage system to get rid of excess fluid and particles. When this system backs up or doesn't drain well, extra fluid can enter the abdomen.
- decreased amounts of albumin and other proteins in the blood. This causes what is called decreased osmotic pressure. Albumin and blood proteins help to keep fluid within the blood vessels. When their amounts are decreased, the fluid can leak out of the blood vessels and accumulate.
- increased leakage of fluid from tiny blood vessels called capillaries due to inflammation or infection.
- inability of the kidneys to eliminate salt and water in a normal fashion.
Depending on the amount of ascites and the cause, there may be no symptoms at all.
Commonly encountered symptoms include:
What are the causes and risks of the condition?
- increasing abdominal girth
- abdominal pain
- low back pain
- difficulty breathing, especially when trying to take deep breaths.
- shortness of breath
- difficulty walking
- feeling full after eating only small amounts of food
- changes in bowel function
There are many different disease states that can result in ascites.
Increased hydrostatic pressure can be caused by:
Increased leakage of fluid can be caused by:
- cirrhosis, or permanent scarring of the liver
- alcoholic hepatitis, which is inflammation of the liver due to alcohol abuse
- sudden liver failure, which can be due to many different conditions such as infection or medication reactions
- congestive heart failure
- obstruction in the inferior vena cava, one of the largest veins in the body
- an abnormal tightening of the lining around the heart, which is called constrictive pericarditis
- liver cancer
- other cancers
Decreased osmotic pressure can be caused by:
- bile leaking into the abdomen
- pancreatic fluid leaking into the abdomen
- lymph drainage leaking into the abdomen
- blood or fluid leaking from the blood vessels into the abdomen
What can be done to prevent the condition?
- certain kidney conditions
- severe malnutrition
- gastrointestinal diseases that cause a loss of protein, like inflammatory bowel disease. This condition is an inflammation of the bowel from unknown causes.
- end-stage liver disease, such as cirrhosis
- inflammation of the lining of the abdomen, known as peritonitis, due to a bacterial infection or other causes
- tumours on the lining of the abdomen, known as the peritoneum, such as ovarian, stomach, uterine, pancreatic, breast and lung cancers
- tuberculosis that has infected the peritoneum, which is called tuberculous peritonitis
Ascites can be a result of many different diseases. Prevention of ascites itself is a function of either prevention of the disease causing ascites or treatment of the disease. For example, avoidance of alcohol abuse can prevent cirrhosis, one of the more common causes of ascites.
How is the condition diagnosed?
The diagnosis of ascites is sometimes made clinically from the history and physical examination. The doctor may be able to detect the presence of fluid in the abdomen. There may be abdominal distension, bulging flanks from the fluid, and other signs that can be detected by careful examination. Special x-ray tests are also commonly used to diagnose ascites and help determine the cause.
A diagnostic test, called paracentesis, may be done. This involves the insertion of a needle through the skin and into the abdominal cavity to withdraw fluid. Testing the fluid helps to determine the cause of the ascites. For example, an elevated white blood cell count (WBC) may indicate an infection of the fluid.
What are the long-term effects of the condition?
Most long-term effects are due to the underlying disease. Long-term effects of ascites can include:
What are the risks to others?
- gastrointestinal problems
- difficulty breathing
- kidney failure
- heart failure
- difficulty sleeping
- difficulty walking and performing daily activities
There are no risks to others, as ascites is not contagious.
What are the treatments for the condition?
Treatment should target the underlying cause of the ascites if possible.
There are some general treatment guidelines followed for ascites itself:
The majority of patients respond to these measures. About 10% to 15% are resistant and require other methods to control the ascites.
- hospitalisation may be required to search for the cause of the ascites and to monitor the daily weight and salt balance.
- bed rest may be used to improve kidney function.
- salt restriction is very important. A diet containing no more than 2 grams of sodium or salt per day is used.
- fluid restriction of 1 litre a day is used if the blood sodium levels are low.
- diuretics, which are pills that cause urination or "water" pills, may be used. Examples include spironolactone, amiloride, or triamterene. These are used if there is not sufficient loss of sodium and weight with diet and fluid restrictions. If these medications fail, other diuretics like frusemide, thiazide, or ethacrynic acid, may be used.
- With massive ascites, hospitalised patients may be advised to undergo removal of large volumes of ascitic fluid using paracentesis. This procedure is occasionally done in a doctor's office, where a needle is inserted into the abdominal cavity.
These measures can include:
In rare and selected cases, liver transplantation may be indicated.
- surgical placement of a shunt or tube connecting the peritoneum to a large vein called the vena cava. This is known as a peritoneovenous shunt. This shunt has a pressure-sensitive, one-way valve that allows ascites to flow from the peritoneum into the vena cava.
- transjugular intrahepatic portosystemic shunt (TIPS). This is an expandable mesh stent or tube that is passed through the skin of the neck and into the jugular vein. The tube is then advanced down through the veins and into the liver. The stent is pushed through the liver and into the portal vein, which drains into the liver. It creates a shunt of blood across the liver in an attempt to reduce pressure and ascites formation.
What are the side effects of the treatments?
Side effects of diuretics can include:
Removal of large volumes of fluid using parencentesis may cause:
- high or low potassium levels in the blood
- kidney failure
Side effects of shunting procedures can include:
- low blood pressure, called hypotension
- decreased kidney function
What happens after treatment for the condition?
- clotting of the shunt
- abnormal blood clotting that may result in bleeding
- change in mental functioning or level of consciousness (hepatic encephalopathy)
The goal of treatment is to control the amount of ascites. Treatment needs to be adjusted so that ascites is lost gradually. The rule of thumb is to have the patient lose 0.5 kg, or roughly 1 pound, per day. Ongoing treatment is often needed for life.
How is the condition monitored?
Continuous monitoring of ascites treatment is important to determine the effectiveness of control. This includes:
Author: Susan Woods, MD
- monitoring weight, sodium and fluid intake
- measuring blood electrolytes, which include various salts such as sodium and potassium, blood protein and albumin
- monitoring the ease of breathing
- monitoring gastrointestinal function
- monitoring liver and kidney function
- watching for any signs of infection
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Potential conflict of interest information for reviewers available on request