Peritonitis - Causes, Symptoms and Treatments

Peritonitis is an acute or chronic inflammation of the peritoneum, the membrane that lines the abdominal cavity and covers the visceral organs. Inflammation may extend throughout the peritoneum or may be localized as an abscess.

Peritonitis commonly decreases intestinal motility and causes intestinal distention with gas. Mortality is 10%, with death usually resulting from bowel obstruction: the mortality rate was much higher before the introduction of antibiotics.

Causes of Peritonitis:

Although the GI tract normally contains bacteria, the peritoneum is sterile. In peritonitis, however, bacteria invade the peritoneum. Generally, such infection results from inflammation and perforation of the GI tract, allowing bacterial invasion. Usually, this results from appendicitis, diverticulitis, peptic ulcer, ulcerative colitis, volvulus, strangulated obstruction, abdominal neoplasm, or a penetrating wound.

Peritonitis may also result from chemical inflammation, as in rupture of the fallopian tube or the bladder; perforation of a gastric ulcer; or released pancreatic enzymes.

In both chemical and bacterial inflammation, accumulated fluids containing protein and electrolytes make the transparent peritoneum opaque, red, inflamed, and edematous. Because the peritoneal cavity is so resistant to contamination, such infection is often localized as an abscess instead of disseminated as a generalized infection.

Signs and symptoms of Peritonitis:

The key symptom of peritonitis is sudden, severe, and diffuse abdominal pain that tends to intensify and localize in the area of the underlying disorder. Direct or rebound tenderness may be elicited over an area affected by diverticulitis.

Pain may be accompanied by anorexia, nausea, vomiting, and altered bowel habits (particularly constipation). For instance, if appendicitis causes the rupture, pain eventually localizes in the lower right quadrant. The patient often displays weakness, pallor, excessive sweating, and cold skin as a result of excessive loss of fluid, electrolytes, and protein into the abdominal cavity.

Decreased intestinal motility and paralytic ileus result from the effect of bacterial toxins on the intestinal muscles. Intestinal obstruction causes nausea, vomiting, and abdominal rigidity.

Other typical clinical features include hypotension, tachycardia, signs of dehydration (oliguria, thirst, dry swollen tongue, pinched skin), acutely tender abdomen associated with rebound tenderness, temperature of 103° F (39.4° C) or higher, and hypokalemia. Inflammation of the diaphragmatic peritoneum may cause shoulder pain and hiccups.

Abdominal distention and resulting upward displacement of the diaphragm may decrease respiratory capacity. Typically, the patient with peritonitis tends to breathe shallowly and move as little as possible to minimize pain.

Diagnosis of Peritonitis:

Severe abdominal pain in a patient with direct or rebound tenderness suggests peritonitis. Abdominal X-rays showing edematous and gaseous distention of the small and large bowel support the diagnosis. In the case of perforation of a visceral organ, the X-ray shows air in the abdominal cavity. Other appropriate tests include:

1. chest X-ray - may show elevation of the diaphragm

2. blood studies - shows leukocytosis (more than 20,000/ul)

3. paracentesis-reveals bacteria, exudate, blood, pus, or urine

4. Laparotomy - may be necessary to identify the underlying cause.

Other conditions to consider are acute appendicitis, pancreatitis, cholecystitis, and pelvic inflammatory disease.

Treatment of Peritonitis:

Early treatment of GI inflammatory conditions and preoperative and postoperative antibiotic therapy help prevent peritonitis. After peritonitis develops, emergency treatment must combat infection, restore intestinal motility, and replace fluids and electrolytes.

Empiric antibiotic therapy usually includes administration of cefoxitin with an amino glycoside or penicillin G and clindamycin with an aminoglycoside, depending on the infecting organisms. To decrease peristalsis and prevent perforation, the patient should receive nothing by mouth; I.V. fluids are administered. Other supportive measures include preopcrative and postoperative administration of analgesia and nasogastric (NG) decompression.

When peritonitis results from perforation, surgery is necessary. The aim of surgery is to eliminate the source of infection by evacuating the spilled contents and repairing any organ perforation.

Special considerations of Peritonitis:

1. Monitor vital signs, fluid intake and output, and the amount of NG drainage or vomitus.

2. Place the patient in semi-Fowler's position to facilitate pulmonary toileting.

3. Encourage the patient to deep-breathe, cough effectively, and use an incentive spirometer.

4. Teach splinting of the incision to facilitate pulmonary toileting.

5. Counteract mouth and nose dryness due to fever and NG intubation with regular cleaning and lubrication.

6. Maintain parenteral fluid and electrolyte administration as ordered. Accurately record fluid intake and output, including NG and incisional drainage.

7. Place the patient in Fowler's position to promote drainage (through drainage tube) by gravity.

8. Encourage and assist ambulation as ordered, usually on the first postoperative day.

9. Observe for signs of dehiscence (the patient may complain that "something gave way") and abscess formation (persistent abdominal tenderness and fever).

10. Frequently assess for peristaltic activity by listening for bowel sounds and evaluating for passage of flatus, bowel movements, and soft abdomen.

11. When peristalsis returns and temperature and pulse rate are normal or when NG output diminishes (less than 200 cc/24 hrs), the NG tube is removed.

12. Gradually decrease parenteral fluids and increase oral intake.