Peritonitis overview

Peritonitis Main Page
Patient Information
Overview
Causes
Classification Spontaneous Bacterial Peritonitis Secondary Peritonitis
Differential Diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief:  ; Shivani Chaparala M.B.B.S [2]

Overview

Peritonitis is defined as inflammation of the peritoneum (the serous membrane which lines part of the abdominal cavity and some of the viscera it contains). It may be localised or generalised, generally has an acute course, and may depend on either infection (often due to rupture of a hollow viscus) or on a non-infectious process. Peritonitis generally represents a surgical emergency.

Classification

Peritonitis may be classified into Infective and non-infective subtypes.

• '''Infective peritonitis''' is classified as either diffuse or localized, primary , secondary, or tertiary and is further characterized as “uncomplicated” or “complicated.”
  • Primary peritonitis is spontaneous infection of the peritoneal cavity, usually associated with liver disease and ascites [spontaneous bacterial peritonitis (SBP)].
  • Secondary peritonitis is infection of the peritoneal cavity due to spillage of organisms into the peritoneum, usually associated with GI perforation.
  • Tertiary peritonitis is a recurrent infection of the peritoneal cavity following an episode of secondary peritonitis without a surgically treatable focus, may be due to disturbance in the host's immune response.
  • Uncomplicated peritonitis is infection contained within a single organ without anatomic disruption.
  • Complicated peritonitis involve extension of infection beyond the organ, either localized or generalized peritonitis, with spillage of microorganisms into the sterile peritoneal space.
  • Continuous Ambulatory Peritoneal Dialysis (CAPD) peritonitis is the major complication of peritoneal dialysis and most often is due to touch contamination or catheter-related infection.

• Non-infective peritonitis is due to leakage of sterile body fluids into the peritoneum, such as blood (e.g., endometriosis, blunt abdominal trauma), gastric juice (e.g., peptic ulcer, gastric carcinoma), bile (e.g., liver biopsy), urine (pelvic trauma), menstrum (e.g., salpingitis), pancreatic juice (pancreatitis), or even the contents of a ruptured dermoid cyst which subsequently become infected once they leak out of their organ, leading to infectious peritonitis within 24 to 48 hours.
  • Aseptic peritonitis occurs as an acute reaction to foreign substance (e.g., gauze, sponge) left during a procedure.

• Peritonitis may also be classified into ''Community acquired'' and ''Health care associated'' types.
  • Community acquired account for 80% of infections and are graded from “mild to moderate” to “more severe” on the basis of physiologic scoring systems (Acute Physiology and Chronic Health Evaluation II [APACHE II]), the patient's comorbid conditions, underlying immune status, and an inability to achieve adequate source control.
  • Health care associated infections are most commonly acquired as complications of previous elective or emergency abdominal surgeries.

Pathophysiology

The peritoneum normally appears greyish and glistening; it becomes dull 2-4 hours after the onset of peritonitis, initially with scarce, serous, or slightly turbid fluid. Later on, the exudate becomes creamy and evidently suppurative; in dehydrated patients, it also becomes very inspissated. The quantity of accumulated exudate varies widely. It may be spread to the whole peritoneum, or be walled off by the omentum and viscera. Inflammation features infiltration by neutrophils with fibrino-purulent exudation.

Risk Factors

Patients with liver disease are at increased risk. Risk factors for liver disease include alcoholic cirrhosis and other diseases that lead to cirrhosis, such as viral hepatitis (Hepatitis B or C). Spontaneous peritonitis also occurs in patients who are on dialysis for kidney failure.

Natural History, Complications and Prognosis

Prognosis

With treatment, patients usually do well. Without treatment, the outcome is usually poor. However, in some cases, patients do poorly even with prompt and appropriate treatment.

Diagnosis

History and Symptoms

The main manifestations of peritonitis are acute abdominal pain, tenderness, and guarding, which are exacerbated by moving the peritoneum, e.g. coughing, flexing the hips, or eliciting the Blumberg sign (a.k.a. rebound tenderness, meaning that pressing a hand on the abdomen elicits pain, but releasing the hand abruptly will aggravate the pain, as the peritoneum snaps back into place).

Abdominal pain and tenderness: The localization of these manifestations depends on whether peritonitis is localized (e.g. appendicitis or diverticulitis before perforation), or generalized to the whole abdomen; even in the latter case, pain typically starts at the site of the causing disease. Peritonitis is an example of acute abdomen.

Laboratory Findings

A diagnosis of peritonitis is based primarily on clinical grounds, that is on the clinical manifestations described above; if they support a strong suspicion of peritonitis, no further investigation should delay surgery. Leukocytosis and acidosis may be present, but they are not specific findings. Plain abdominal X-rays may reveal dilated, oedematous intestines, although it is mainly useful to look for pneumoperitoneum (free air in the peritoneal cavity), which may also be visible on chest X-rays. If reasonable doubt still persists, an exploratory peritoneal lavage may be performed (e.g. in cause of trauma, in order to look for white blood cells, red blood cells, or bacteria).

Treatment

Surgery

Surgery (laparotomy) is needed to perform a full exploration and lavage of the peritoneum, as well as to correct any gross anatomical damage which may have caused peritonitis. The exception is spontaneous bacterial peritonitis, which does not benefit from surgery.

References

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