Peritonitis

Peritonitis is an inflammation of the peritoneum, which is the membrane that lines the wall of the abdomen and covers the abdominal organs.

Causes and risk factors

The types of peritonitis include:

• Spontaneous peritonitis: an infection that occurs as a complication of ascites (a collection of fluid in the peritoneal cavity), which is usually related to liver or kidney failure
• Secondary peritonitis: caused by another condition, most commonly the spread of an infection from the digestive organs or bowels
• Dialysis associated peritonitis: an acute or chronic inflammation (irritation and swelling) of the peritoneum (lining of the abdominal cavity) that occurs in people receiving peritoneal dialysis

Intra-abdominal abscess (abdominal abscess): This condition involves a collection of pus in the abdomen and may cause peritonitis. Before peritonitis develops, it can still cause symptoms that are similar or identical to peritonitis.

An intra-abdominal abscess may arise following:

• Localisation of peritonitis
• Gastrointestinal perforation
• Anastomotic leak
• Haematogenous (bloodstream) spread
• Pelvis
• Subhepatic spaces
• Subphrenic spaces
• Paracolic gutters

Symptoms

• Nausea
• Vomiting
• Abdominal pain, which increases on movement
• Abdominal tenderness
• Abdominal distension
• Fever
• Low urine output
• Point tenderness
• Thirst
• Fluid in the abdomen
• Constipation
• Inability to pass faeces and gas
• Signs of shock in extreme cases

Diagnoses

• Physical examination and medical history
• Blood tests including blood culture and X-rays or CT scans may be ordered
• Peritoneal fluid analysis (paracentesis) and culture

Treatment

The cause must be identified and treated promptly.

Treatment typically involves fluid infusion to control shock, surgery to drain the peritoneal cavity and repair the cause, and antibiotics to deal with the infection. In cases associated with peritoneal dialysis, antibiotics may be infused through the dialysis catheter, but if the infection is severe, the catheter itself must often be removed.

Treatment typically involves surgery and antibiotics. In cases associated with peritoneal dialysis, antibiotics may be infused through the dialysis catheter, but if the infection is severe, the catheter itself must often be removed.

Course of illness

The outcome is often good with treatment, but can be poor without treatment.
Sometimes the outcome is poor even with prompt and adequate treatment.

Complications

Peritonitis can be life-threatening and cause a number of different complications, depending on the type.

Complications may include

• Peritonitis stops the movement of bowel contents (peristalsis), which can block the bowel (paralytic ileus).
• Septic shock - Fluid from the blood accumulates in the abdominal cavity and the loss of fluid from the circulation may also cause shock.
• Abscess
• Intraperitoneal adhesions

What you should do?

Go to the Hospital emergency or call the local emergency number (such as 000, for Australia) if you have symptoms that may indicate peritonitis, as it is a medical emergency.