Peritonitis is the inflammation of the peritoneum. The peritoneum is very much resistant to infections and tends to limit infection if the contamination does not continue. Peritonitis is usually due to contamination of the abdominal cavity from any cause.
Causes: 1. Spread of infection from an infected organ like appendix, gall bladder, a gangrenous segment of bowel or fallopian tubes in women.
2. Perforation of bowel like duodenum, intestines or appendix.
3. Introduction of infection into the abdominal cavity from outside during surgery, peritoneal dialysis or laparoscopy or penetrating injuries.
4. Primary peritonitis due to no known cause.
5. Non-infective peritonitis due to irritation by chemicals like glove powder or enzymes from pancreatitis.
Clinical features: What ever be the origin , peritonitis has a uniform clinical picture. The patient complains of severe pain in abdomen, usually associated with vomiting. The pain starts from the location of the source infection , for example, it starts in the upper abdomen in perforated duodenal ulcer and cholecystitis, in the right ileac fossa in acute appendicitis and lower abdomen in fallopian tubes' infection. Then the pain spreads to all over the abdomen. The patient develops fever and in later stages the abdomen gets distended. There will be guarding and rigidity over the abdomen. Bowel sounds diminish and ultimately end up as a silent abdomen. Because of loss of fluid into the bowel and peritoneal cavity and associated vomiting, the patient gets dehydrated rapidly. Fluid loss and sepsis lead to hypotension and shock. In late stages of peritonitis the patient presents as a dehydrated and debilitated person without any interest in the surroundings. The patient develops shallow breathing and urine output gets low or absent. If not treated, shock and kidney failure lead to death.
Diagnosis: The typical picture of pain abdomen associated with guarding , rigidity and tenderness is diagnostic. Xray of the abdomen in erect posture or lateral position may show free air in the peritoneal cavity indicating a perforation of the bowel. Needle aspiration of the peritoneal fluid may help in diagnosing the peritonitis and the organisms causing it. Laparotomy is the most reliable diagnostic and therapeutic measure.
Treatment: Preliminary administration of intra-venous fluids is very important to resuscitate the patient. Nasogastric suction is initiated. Antibiotics are administered to combat infection. Pulse, blood pressure and other parameters are monitored closely. Once the general condition has improved, exploratory laparotomy is conducted. During surgery the source of infection is dealt with (appendicectomy, closure of perforation or resection of a gangrenous segment of bowel). The infected peritoneal fluid is sucked out and the peritoneal cavity is washed out with several litres of normal saline to which antiseptics like povidone iodine are added. A drain may be kept if necessary. Post operatively antibiotics and intravenous fluids are continued till the recovery is complete. Once the bowel sounds return to normal, the patient is switched over to oral fluids and slowly solid diet is introduced. Laparoscopic exploration is a good alternative to open surgery in the hands of persons well experienced with laparoscopy in the treatment of peritonitis.
Complications: Complications of peritonitis include lung, liver or kidney failure, abscess formation or generalized clotting failure in the early stages and formation of adhesions and bands causing intestinal obstruction in late stages.