Acute Peritonitis

DESCRIPTIONS
* Acute peritonitis is an inflammatory process within the abdominal cavity. It is usually due to a bacterial infection and is treated with antibiotics.
* In some cases, the infection occurs independent of outside infection, and is known as Spontaneous Bacterial Peritonitis (SBP). SBP usually occurs in patients who have Ascites (fluid in the abdominal cavity) from some other cause. Most people normally have only a very small amount of fluid in the stomach cavity. However, certain diseases can lead to the accumulation of fluid within the abdomen. This fluid can get infected, in turn, and cause peritonitis.
* About 20 to 30% of patients with Ascites will develop SBP. In other cases, peritonitis is caused by some other condition, and this is known as secondary bacterial peritonitis.
* In a few cases, the condition may be due to less common causes, such as Tuberculosis, cancer, or other processes. In cases of bacterial peritonitis, treatment is with antibiotics. In other cases, the underlying condition has to be treated.


SYMPTOMS
* Most patients with peritonitis will have abdominal pain and a fever.
* Also, they usually already have Ascites (a build-up of fluid within their stomach) and a distended stomach. Peritonitis may or may not cause the stomach to be more distended than normal.
* Some patients will have nausea, vomiting, loss of appetite, and weight loss. Which of these symptoms are present depends on the cause of the problem.
* Many patients with Ascites also have liver problems. When these patients develop peritonitis, they often experience deterioration in mental status because of the build-up of toxic substances in their blood.
* Patients with tuberculous peritonitis have low-grade fever, loss of appetite, and weight loss. Often, their Ascites will develop slowly.
* In patients with cancer, the cancer can spread to the peritoneum (the abdominal cavity). If this happens, it triggers a reaction and causes the accumulation of fluid. This can cause an abnormal increase in the size of the abdomen, loss of appetite, and lack of energy.
* If there is a large amount of fluid within the stomach cavity, the patient may have trouble breathing because the lungs cannot expand normally. Also, fluid may block the intestine and not allow food to pass through.
* Examination by a doctor usually reveals tenderness of the abdomen, and fever.

CAUSE
* As stated above, there are many factors that cause peritonitis.
* Secondary bacterial peritonitis is usually caused by an infection somewhere in the abdomen. For example, Diverticulitis, Appendicitis, pancreatitis, intestinal perforation, etc., all can cause this problem. Most abdominal infections stay within the infected organ. When the infection spreads out of the organ and into the abdominal cavity, it causes peritonitis. This is known as secondary bacterial peritonitis. Also, any type of trauma that introduces bacteria into the abdominal cavity can lead to peritonitis.
* Spontaneous Bacterial Peritonitis occurs when the fluid within the abdominal cavity becomes infected on its own. This process almost always occurs in patients who already have Ascites. It is called spontaneous because the bacteria enter the abdominal cavity on their own by moving through the wall of the intestine. There is no outside source for the infection, such as in secondary bacterial peritonitis.
* The risk of Spontaneous Bacterial Peritonitis (SBP) is higher in patients who have liver disease and who have a low amount of protein in their Ascites fluid.
* Another cause of peritonitis is Tuberculosis infection of the abdominal cavity.
* Cancer can also spread to the abdominal cavity and cause the development of Ascites. The most common tumors that spread to the abdominal cavity include cancer from the ovaries, uterus, pancreas, stomach, colon, lungs, and breasts.
* A disease called familial Mediterranean fever also can cause peritonitis.

HOW THE DIAGNOSIS IS MADE
* The symptoms and doctor's examination may suggest the presence of peritonitis, or peritonitis might be diagnosed during abdominal surgery.
* However, the only way to be sure is to remove some of the fluid and send it to the lab. This is done by a process known as paracentesis. In a paracentesis, a needle is inserted into the abdomen and a sample of the fluid is removed. The fluid is then sent to the lab where it is analyzed.
* Once, the test results are back, decisions regarding treatment can be made.
* This test will only tell you whether or not an infection is present. It will not necessarily tell you the source of the infection.
* Once the diagnosis of an infection (peritonitis) is made, then it has to be determined whether this is spontaneous or secondary bacterial peritonitis.
* Spontaneous Bacterial Peritonitis usually responds to antibiotic therapy within 24 to 48 hours.
* If the patient is placed on antibiotics and is not improving after 1 to 2 days, the doctor may need to repeat the paracentesis to recheck the fluid. The doctor has to take into consideration that the lack of improvement may be due to secondary bacterial peritonitis or some other disease.
* If secondary bacterial peritonitis is felt to be present, the doctor will have to do more testing to see what is causing the problem. Tests may include Ultrasound, CAT scan, and special X-Rays (such as an upper gastrointestinal series or a gastrograffin enema). The most appropriate test will be determined by your doctor.
* Tuberculous peritonitis is often very hard to diagnose. Often, the fluid collected from the abdomen will not give a specific diagnosis. In such cases, the patient may need a biopsy to see if the infection is due to Tuberculosis. The biopsy can be done by laparoscopic surgery, in which a camera is inserted into the abdomen via 2 or 3 small incisions. The doctor can then look around and perform a biopsy.
* In patients with peritonitis due to cancer, the fluid can be collected and analyzed in the laboratory to see if any cancer cells are present. If this does not give a final diagnosis, then laparoscopic surgery can be done (as described above) to obtain a biopsy.
* In patients with familial Mediterranean fever, they can undergo genetic testing to see if they have this disease.

RISK FACTORS
* Risk factors for developing peritonitis include the presence of Ascites. Therefore, any condition that leads to the formation of Ascites can also be considered a risk factor for peritonitis.
* Also, a low amount of protein (less than 1 gram per deciliter) in the Ascites fluid is a risk factor for developing peritonitis.
* Any other abdominal infection such as Appendicitis, Diverticulitis, perforation, etc can lead to peritonitis.
* Having had peritonitis previously is a risk factor for developing peritonitis again.

TREATMENT
* Treatment depends on the cause of the peritonitis.
* In general, patients who have Ascites are placed on diuretics. A diuretic is a type of medication that increases urine output and helps remove excess fluid from the body. It is often also known as a "water pill."
* Treatment for secondary peritonitis is addressed at taking care of the underlying infection or problem. The person will need to be placed on antibiotics. However, the most appropriate treatment depends on the cause of the problem.
* Treatment for SBP is with antibiotics. Usually the person is treated with an antibiotic such as cefotaxime. If needed, another antibiotic called ampicillin can be also be used. Antibiotics are usually continued for 1-2 weeks.
* In certain special circumstances (for example those who do peritoneal dialysis), they may need different antibiotics. Therefore, the doctor treating the person will help decide which antibiotic is most appropriate.
* Patients with Ascites due to cancer usually do not require antibiotics. They also usually do not respond to medicines that increase urine output (diuretics). These individuals usually require a procedure known as large volume paracentesis. This procedure is the same as that described above (in the diagnosis section). However, instead of removing just a small sample for analysis, a large amount of the fluid is removed to help reduce the person's symptoms.
* Patients with familial Mediterranean fever sometimes can be treated with a medicine called Colchicine (which is often used in patients with gout) to help reduce the frequency and severity of symptoms. However, no specific cure for this condition is currently available.

COMPLICATIONS
* Usually, most cases of peritonitis due to an infection respond to antibiotics.
* If the infection does not respond, the infection may get worse or spread to other parts of the body.
* Other complications include Intestinal Obstruction, shortness of breath, or development of fluid build-up around the lungs (called a pleural effusion).

IF YOU SUSPECT THIS CONDITION
* If you suspect this condition, please seek medical attention as soon as possible.

PREVENTION
* Things such as fluid collections due to cancer cannot really be prevented.
* Peritonitis due to other causes (secondary bacterial peritonitis) can potentially be prevented if those conditions are diagnosed and treated quickly.
* Tuberculous peritonitis can sometimes be prevented if the infection is detected elsewhere in the body and treatment is started early.
* Spontaneous Bacterial Peritonitis has a high rate of occurring again in patients who have already had it once. Therefore, antibiotics are often given to these patients to prevent repeat infections. These antibiotics are also given to patients with very low amounts of protein in their Ascites (remember a low protein level greatly increases the risk of developing SBP).
* The antibiotics most often used are ciprofloxacin (750 milligrams once a week), Norfloxacin (400 milligrams once a day), or Trimethoprim-sulfamethoxazole (one double-strength tablet a day).
* These antibiotics, though not a 100% effective, do greatly reduce the risk of developing an infection.

SIMILIAR CONDITIONS
* Diverticulitis
* Pancreatitis
* Cholecystitis
* Cholangitis
* Pancreatitis
* Chylous, pancreatic, or bile Ascites
* Bowel obstruction
* Appendicitis