Sandbox:peritonitis

Definition

Peritonitis defined as the inflammation of the peritoneum from any cause which lines abdominal cavity and the internal organs as a serosal membrane. Contrast to peritonitis, Intrabdominal infection is defined as the inflammation of peritoneum due to infectious cause.

Primary or Spontaneous Peritonitis

Primary peritonitis is defined as the infection of the peritoneal cavity which is spontaneous and often associated with liver disease and ascites. It is also known as spontaneous bacterial peritonitis. Primary peritonitis lacks an identifiable anatomical derangement.

Secondary Peritonitis

Secondary peritonitis is defined as the infection of the peritoneum due to spillage of organisms into the peritoneal cavity resulting from hollow viscus perforation, anastomotic leak, ischemic necrosis, or other injuries of the gastrointestinal tract.

Tertiary Peritonitis

Tertiary peritonitis is defined as the persistant or recurrent intra-abdominal infection that occur in ≥48 hours following the successful and adequate surgical source control of primary or secondary peritonitis.

Bacterascitis

Bacterascites is defined as the presence of culture positivity without increase in PMN count in the ascitic fluid.

Historical Perspective

The first reports describing this entity appeared in the German and French literatures between 1907 and 1958.

Classification

Peritonitis is classified based on the etiology as follows:

Peritonitis

Primary peritonitis

Secondary peritonitis

Tertiary peritonitis

❑ Spontaneous peritonitis ❑ Peritonitis in patients with CAPD ❑ Tuberculous peritonitis

❑ Peritonitis without evidence for pathogens ❑ Peritonitis with fungi ❑ Peritonitis with low-grade pathogenic bacteria

Acute perforation peritonitis ❑ Gastrointestinal perforation ❑ Intestinal ischemia ❑ Pelviperitonitis and other forms

Postoperative peritonitis ❑ Anastomotic leak ❑ Accidental perforation and devascularization

Post-traumatic peritonitis ❑ After blunt abdominal trauma ❑ After penetrating abdominal trauma

Pathogenesis

Peritonitis can be regarded as the localized event after any trigger of inflammation similar to the systemic inflammatory response(SIRS).

Primary peritonitis

As the primary disease (e.g. cirrhosis) progresses, gram negative bacteria increase in numbers in the gut. Once bacteria reach a critical concentration in the gut lumen, they will translocate into the mesenteric lymphatic system because of the failure of the gut to contain bacteria and failure of the immune system to kill the virulent bacteria once they have escaped the gut result in bacteremia and endotoxinemia.

Secondary peritonitis develops perforation of intra abdominal organs when bacteria contaminate the peritoneum as a result of spillage from an intraabdominal viscus. The organisms found almost always constitute a mixed flora in which facultative gram-negative bacilli and anaerobes predominate, especially when the contaminating source is colonic.

Causes

Common Causes

Primary Peritonitis	Secondary Peritonitis	Tertiary Peritonitis
Cirrhosis with ascitis Portal hypertension with ascitis Renal failure patient with continuous ambulatory peritoneal dialysis (CAPD)	Ruptured gastric ulcer, appendicular abscess or diverticular abscess Inflamatory bowel diseases such as chron's disease or ulcerative colitis with toxic megacolon Pelvic inflamatory disease Recent surgical procedures Recent trauma to the abdomen (e.g. Stab injury or gun shot injury)

Epidemiology

SBP is the most frequent bacterial infection in cirrhosis, accounting for 10-30% of all reported bacterial infections in hospitalised patients.

The prevalence of SBP in outpatient setting asymptomatically is low (< 3.5% ), but the prevalence increases to 8%-36% in the nosocomial setting.

Mortality rate for the first episode of SBP in in-patient setting varies between 10-50%, depending upon the risk factors. One-year mortality after a first episode of SBP has been reported to be 31% and 93%.

Diagnosis

Identification of risk factors and individualisation of timing and selection of prophylactic measures are the key to success without major development of resistant bacteria.

Varient of Spontaneous bacterial peritonitis (SBP)	Ascitic fluid analysis and other information
SBP culture postive	PMNs ≥250 cells/mm3 and culture positivity Patients with cirrhosis and ascites in the presence or absence of symptoms and signs
Culture-negative neutrocytic ascites(CNNA) or culture-negative SBP	PMNs ≥250 cells/mm3 and culture negativity Poor culture technique and prior antibiotics or low opsonic activity in ascitic fluid. Commonly encountered phenotype and requires antibiotic therapy
Monomicrobial bacterascites	PMNs <250 cells/mm3 and culture positivity Ascitic fluid infection which may resolve spontaneously or progress to SBP. Similar mortality to SBP and should be treated the same

Treatment

Primary Peritonitis

The flora of primary peritonitis is typically monomicrobial.

Secondary Peritonitis

Treatment of secondary peritonitis depends on the etiological factor and effective therapy includes cause specific surgical intervention and adjunctive antibiotic therapy.

Prevention

Prophylaxis is of crucial relevance when trying to improve survival.