Classification & external resources
- This article is concerned with peritonitis in human beings. For a specific cause of peritonitis in cats, see feline infectious peritonitis.
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.
Mechanisms & manifestations
Abdominal pain & tenderness
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). The localisation of these manifestations depends on whether peritonitis is localised (e.g. appendicitis or diverticulitis before perforation), or generalised 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.
- the fluid may push on the diaphragm and cause breathing difficulties
Diagnosis and investigations
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).
- Perforation of a hollow viscus is the most common cause of peritonitis. Examples include perforation of the distal oesophagus (Boerhaave syndrome), of the stomach (peptic ulcer, gastric carcinoma, of the duodenum (peptic ulcer), of the remaining intestine (e.g. appendicitis, diverticulitis, Meckel diverticulum, IBD, intestinal infarction, intestinal strangulation, colorectal carcinoma, meconium peritonitis), or of the gallbladder (cholecystitis). Other possible reasons for perforation include trauma, ingestion of sharp foreign body (such as a fish bone), perforation by an endoscope or catheter, and anastomotic leakage. The latter occurrence is particularly difficult to diagnose early, as abdominal pain and ileus paralyticus are considered normal in patients who just underwent abdominal surgery. In most cases of perforation of a hollow viscus, mixed bacteria are isolated; the most common agents include Gram-negative bacilli (e.g. Escherichia coli) and anaerobic bacteria (e.g. Bacteroides fragilis).
- Disruption of the peritoneum, even in the absence of perforation of a hollow viscus, may also cause infection simply by letting micro-organisms into the peritoneal cavity. Examples include trauma, surgical wound, continuous ambulatory peritoneal dialysis, intra-peritoneal chemotherapy. Again, in most cases mixed bacteria are isolated; the most common agents include cutaneous species such as Staphylococcus aureus, and coagulase-negative staphylococci, but many others are possible, including fungi such as Candida.
- Spontaneous bacterial peritonitis (SBP) is a peculiar form of peritonitis occurring in the absence of an obvious source of contamination. It occurs either in children, or in patients with ascites. See the article on spontaneous bacterial peritonitis for more information.
- Systemic infections (such as tuberculosis) may rarely have a peritoneal localisation.
- 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), menstruum (e.g. salpingitis), pancreatic juice (pancreatitis), or even the contents of a ruptured dermoid cyst. It is important to note that, while these body fluids are sterile at first, they frequently become infected once they leak out of their organ, leading to infectious peritonitis within 24-48h.
- Sterile abdominal surgery normally causes localised or minimal generalised peritonitis, which may leave behind a foreign body reaction and/or fibrotic adhesions. Obviously, peritonitis may also be caused by the rare, unfortunate case of a sterile foreign body inadvertently left in the abdomen after surgery (e.g. gauze, sponge).
- Much rarer non-infectious causes may include familial Mediterranean fever, porphyria, and systemic lupus erythematosus.
Depending on the severity of the patient's state, the management of peritonitis may include:
If properly treated, typical cases of surgically correctable peritonitis (e.g. perforated peptic ulcer, appendicitis, and diverticulitis) have a mortality rate of about <10% in otherwise healthy patients, which rises to about 40% in the elderly, and/or in those with significant underlying illness, as well as in cases that present late (after 48h). If untreated, generalised peritonitis is almost always fatal.
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.
- ^ Peritonitis: Emergencies: Merck Manual Home Edition. Retrieved on 2007-11-25.
- Peritonitis disease causes, treatment ...
- All Refer Health article on peritonitis
- Genuit T and Napolitano L. 2004. Peritonitis and Abdominal Sepsis. Emedicine.com
- Health square. 2004. Peritonitis.
|Digestive system - Gastroenterology (primarily K20-K93, 530-579)|
|Esophagus||Esophagitis - GERD - Achalasia - Boerhaave syndrome - Nutcracker esophagus - Zenker's diverticulum - Mallory-Weiss syndrome - Barrett's esophagus|
|Peptic (gastric/duodenal) ulcer - Gastritis - Gastroenteritis - Duodenitis - Dyspepsia - Pyloric stenosis - Achlorhydria - Gastroparesis - Gastroptosis - Portal hypertensive gastropathy|
|Hernia||Inguinal (Indirect, Direct) - Femoral - Umbilical - Incisional - Diaphragmatic - Hiatus|
|Noninfective enteritis and colitis||IBD (Crohn's, Ulcerative colitis) - noninfective gastroenteritis|
|Other intestinal||vascular (Abdominal angina, Mesenteric ischemia, Ischemic colitis, Angiodysplasia) - Ileus/Bowel obstruction (Intussusception, Volvulus) - Diverticulitis/Diverticulosis - IBS|
other functional intestinal disorders (Constipation, Diarrhea, Megacolon/Toxic megacolon, Proctalgia fugax) - Anal fissure/Anal fistula - Anal abscess - Rectal prolapse - Proctitis (Radiation proctitis)
|Liver/hepatitis||Alcoholic liver disease - Liver failure (Acute liver failure) - Cirrhosis - PBC - NASH - Fatty liver - Peliosis hepatis - Portal hypertension - Hepatorenal syndrome|
|Accessory digestive||Gallbladder (Gallstones, Choledocholithiasis, Cholecystitis, Cholesterolosis, Rokitansky-Aschoff sinuses)
Biliary tree (Cholangitis, Cholestasis/Mirizzi's syndrome, PSC, Biliary fistula, Ascending cholangitis)
Pancreas (Acute pancreatitis, Chronic pancreatitis, Pancreatic pseudocyst, Hereditary pancreatitis)
|Other/general||Appendicitis - Peritonitis (Spontaneous bacterial peritonitis)
Malabsorption (celiac, Tropical sprue, Blind loop syndrome, Whipple's)
postprocedural: Gastric dumping syndrome - Postcholecystectomy syndrome
bleeding: Hematemesis - Melena - Gastrointestinal bleeding (Upper, Lower)
|See also congenital|