Peritonitis: Etiology and Pathophysiology

Peritonitis: Etiology and Pathophysiology

• Peritonitis is inflammation of the peritoneum, caused by bacteria, irritating chemicals, or both.
• Primary peritonitis involves blood-borne organisms entering the peritoneal cavity, often associated with conditions like cirrhosis and ascites.
• Secondary peritonitis is more common, resulting from ruptured/perforated abdominal organs releasing contents (bile, enzymes, bacteria). Common causes include ruptured appendix, perforated ulcer, diverticulitis, and trauma.
• The initial response is chemical peritonitis, followed by bacterial peritonitis.
• The body's inflammatory response leads to fluid shifts, edema, and adhesions.

Clinical Manifestations

• Severe, continuous abdominal pain is a key symptom.
• Tenderness over the affected area is a common sign.
• Rebound tenderness, rigidity, and spasm indicate peritoneal irritation.
• Patients often lie still, breathing shallowly due to pain exacerbation.
• Other symptoms can include abdominal distention, fever, tachycardia, tachypnea, nausea, vomiting, and changes in bowel habits.
• Severity and speed of onset of underlying condition affect the symptom presentation.
• Potential complications include hypovolemic shock, sepsis, intra-abdominal abscesses, paralytic ileus, and acute respiratory distress syndrome.
• Untreated peritonitis can be fatal.

Diagnostic Studies and Interprofessional Care

• Complete Blood Count (CBC) shows elevated white blood cell count and hemoconcentration due to fluid shifts.
• Peritoneal aspiration analyzes fluid for blood, bile, pus, bacteria, fungus, and amylase levels.
• Abdominal X-rays check for dilated bowel loops (paralytic ileus), free air (perforation), or air/fluid levels (obstruction).
• Ultrasound and CT scans identify ascites and abscesses.
• Peritoneoscopy allows direct visualization of the peritoneum and biopsy for diagnosis (useful if no ascites).
• Conservative care (antibiotics, NG suction, analgesics, IV fluids) for milder cases or poor surgical candidates.
• Surgery is crucial to pinpoint the cause, drain pus, and repair damaged organs.

Common Causes of Peritonitis (Table 47.14)

• Primary: Blood-borne organisms, cirrhosis with ascites.
• Secondary: Ruptured appendix, blunt/penetrating trauma, diverticulitis, intestinal cancer, ischemic bowel, pancreatitis, perforated intestine/uterus/bladder/stomach, perforated peptic ulcer, peritoneal dialysis, postoperative complications (anastomosis breakage).

Nursing Management: Peritonitis

• Assessment: Pain evaluation (location, quality), bowel sounds, abdominal distension/guarding, nausea, fever, and hypovolemic shock signs.
• Clinical Problems: Pain, fluid imbalance, impaired GI function, risk for infection.
• Goals: Inflammation resolution, pain relief, avoidance of complications (sepsis, shock), and normal nutrition.
• Implementation: IV access for fluid/antibiotic administration, pain monitoring/analgesic response, positioning (knee flexion), sedatives for anxiety, accurate I&O monitoring, electrolyte checks, vital sign monitoring, antiemetics for nausea/vomiting, NPO status, NG tube for gastric decompression, oxygen therapy, and insertion of drains (open surgical procedures).