Overview.
Pseudomembranous small bowel colitis (PMC) is an acute mucosal necrotic, fibrinoid exudative inflammatory disease that primarily invades the colon, but can also involve the small bowel. Pseudomembranous small bowel colitis is an enteritis caused by Clostridium difficile proliferating in the intestines due to intestinal dysbiosis caused by antibiotic use. In severe cases, the feces excrete flaky mucosa, once called pseudomembranous enterocolitis. The disease is increasing due to the widespread use of antibiotics, and is also known as antibiotic-associated enterocolitis, which is a common hospital-acquired infectious disease.
Etiology
It was not until the 1970s that Clostridium difficile was confirmed to be the main causative organism of PMC, so the disease was also called Clostridium difficile enteritis, i.e., when the patient’s intestinal flora is imbalanced (intestinal immunocompromise, misuse of antibiotics, and critical condition, etc.), Clostridium difficile abnormally reproduces and produces toxin to damage the mucous membranes, and inflammation and diarrhea with pseudomembrane formation occurs, and it is more common in the elderly. It has been confirmed that the application of antibiotics is the main cause of PMC. In particular, penicillin antibiotics are most likely to induce the disease, followed by cephalosporins, lincomycin, aminoglycosides and so on. In addition, gastrointestinal surgery, inflammatory bowel disease, uremia, intestinal hemorrhage, etc. can also induce PMC, which are related to the lowering of immune function (especially intestinal immune function), and older people are more prone to the disease as their bodies age with age and their immune function decreases.
Symptoms
Pseudomembranous small bowel colitis in most
The majority of patients are elderly, with slightly more women than men. Patients often have certain underlying pathologies, such as intestinal obstruction, inflammatory bowel disease, gastrointestinal surgery, and a variety of critically ill patients, as well as a short-term history of extensive use of broad-spectrum antibiotics.
1. Diarrhea
Pseudomembranous small bowel colitis patients have diarrhea, mostly watery, large amount (> 1 liter / day), severe cases can be discharged with the watery diarrhea of varying sizes of pseudomembranes, the largest can be up to more than ten centimeters long. A small number of patients with serious conditions can be paste, mucus and pus and blood stools.
2. Abdominal pain
The pain is mostly located in the pubic region, the nature of pain is dull pain, distension or spasmodic pain, the patient’s abdomen has no obvious pressure, rebound pain, and occasionally there are signs of peritoneal irritation.
3. Fever
Moderate or high fever, accompanied by dizziness, fatigue and other toxemia symptoms.
4. Water and electrolyte disorders and acid-base imbalance.
Severe diarrhea leads to a large amount of water and salt loss, if not replenished in time, water, electrolyte disorders and acid-base imbalance can occur, and shock can occur in severe cases.
Examination
1. Laboratory examination
(1) Bacterial culture: incubate at 37℃ under anaerobic environment for 24～48 hours. Positive culture results, should also be identified for toxin, because a small number of normal people can carry Clostridium difficile, and this strain does not produce toxin.
(2) Toxin identification is the gold standard for the diagnosis of pseudomembranous small bowel colitis. Tissue cell culture method is mainly used, which is the most sensitive and specific, but the clinical implementation is more difficult. Enzyme-linked immunosorbent assay (ELISA) is not as sensitive as cell culture, but it is fast, simple and economical, and is now used in clinical practice.
(3) Antitoxin neutralization test The cytotoxic effect of Clostridium difficile toxin can be neutralized by Clostridium difficile antitoxin, which can be neutralized by diluting the antitoxin at room temperature or 37℃.
2. Other auxiliary examinations
(1) Endoscopy is a rapid and reliable method to diagnose pseudomembranous small bowel colitis. Endoscopy can be divided into three types of PMC: ① colitis-like type can be seen mucosal congestion and edema, non-specific colitis-like manifestations, mostly seen in patients with mild disease, early disease course, timely treatment. ② light type is still mainly mucosal congestion, edema, visible pseudomembrane, white spots, jump distribution, surrounded by a red halo, red halo between the mucosa is normal, mostly in the early stages of the disease. (3) heavy visible many patchy or map-like pseudomembrane, pseudomembrane for the yellow, yellow-white or yellow-brown, not easy to peel, barely peeled off or peeled off easy to bleed, the peeling surface resembles the endoscopic manifestations of erosive gastritis, most often seen in the disease of severe, advanced, untimely treatment of patients.
(2) Imaging examination Abdominal X-ray film shows dilatation of the colon, fluid in the intestinal lumen and fingerprints, and gas-barium enema double contrast shows disorganization of the mucosa of the colon, brush-like edges and many round or irregular nodular shadows on the surface of the mucosa, and there are fingerprints and signs of ulceration as well.
Diagnosis
Pseudomembranous small bowel colitis should be considered in all critically ill, post-surgical, and elderly patients with chronic illnesses, especially those who have sudden onset of diarrhea and abdominal pain after receiving high doses of antibiotics. The possibility of this disease should be highly suspected if the stools are watery and accompanied by fever and other symptoms. The final diagnosis depends on pathogenetic and histologic examination.
Differential diagnosis
This disease should be differentiated from inflammatory bowel disease, surgical acute abdomen, etc. Differential points include history of antibiotic application, endoscopy, pathologic examination, and toxin test.
Complications
Severe patients may have various complications, such as toxic megacolon, paralytic intestinal obstruction, intestinal perforation, intestinal hemorrhage, shock, DIC, etc. The morbidity and mortality rate is as high as 20%.
Treatment
1. Discontinue related antibiotics
Pseudomembranous small bowel colitis caused by antibiotics should stop using antibiotics immediately. If antibiotics must be used, narrow-spectrum antibiotics or vancomycin can be used.
2. Strengthen symptomatic supportive therapy
If the patient is given water electrolyte supplementation, full parenteral nutrition can be used if necessary. In severe cases, a small amount of hormone can be used to improve the toxemia.
3. Antibacterial treatment
Metronidazole is the antibiotic of choice, and it is effective for the majority of PMC patients. If the efficacy is unsatisfactory or the patient cannot tolerate metronidazole, vancomycin can be used instead.
4. Anti Clostridium difficile toxin therapy
Easily prepared Clostridium difficile antitoxins can be used to neutralize Clostridium difficile toxins.
5. Maintaining normal intestinal flora
Lactasepsin and Bifidobacterium bifidum can be taken orally. In addition, for those rare cases combined with toxic megacolon or intestinal obstruction, they should be treated surgically.
Prevention
Since the application of antibiotics is the main causative agent of pseudomembranous small bowel colitis, and the disease can be induced regardless of the type of antibiotics used, the dosage and the duration of treatment. Therefore, antibiotics, especially broad-spectrum antibiotics, should be avoided in elderly patients, and narrow-spectrum antibiotics can be used when necessary. Once PMC is suspected, relevant antibiotics should be discontinued immediately. In addition, exercise should be strengthened to enhance the resistance of the body.