Pseudomembranous enterocolitis in the elderly

Introduction to pseudomembranous enterocolitis in the elderly Clostridium difficile colitis is caused by the use of antibiotics to cause intestinal flora imbalance, caused by the proliferation of Clostridium difficile in the intestinal tract caused by intestinal inflammation, severe stool excretion of flaky mucosa, once known as pseudomembranous colitis, The disease is increasingly used due to the widespread use of antibiotics, also known as antibiotic-associated enteritis, is a common nosocomial infectious disease. basic knowledge The proportion of illness: 0.001% Susceptible people: the elderly Mode of infection: non-infectious Complications: paralytic ileus, shock, disseminated intravascular coagulation

The cause of pseudomembranous enterocolitis in the elderly

(1) Causes of the disease

Pseudomembranous enterocolitis (PMC) is a kind of acute mucosal necrosis and cellulose exudative inflammation that mainly invades the colon and affects the small intestine. As early as the end of the 19th century, scholars described PMC in detail. However, it failed to find its cause. Although there have been many theories such as low immune function, viral infection and intestinal mucosal blood circulation disorder, etc., trying to explain the cause of this disease, they are not certain. It was not until the 1970s that it was difficult to identify. Clostridium is the main pathogen of PMC, so the disease is also called clostridium difficile enterocolitis, which is when the intestinal flora of the patient is dysfunctional (intestinal immune function is low, antibiotics are abused and The disease is critical, etc.), Clostridium difficile abnormal reproduction, production of toxins, damage to the mucosa and the formation of pseudomembrane inflammation and diarrhea, more common in the elderly.

It has been confirmed that the application of antibiotics is the main cause of PMC, especially penicillin antibiotics are most likely to induce the disease, followed by cephalosporins, lincomycins, aminoglycosides, etc. In addition, gastrointestinal surgery Inflammatory bowel disease, uremia, intestinal bleeding, etc. can also induce PMC, which are related to the reduction of immune function (especially intestinal immune function). The elderly age with the body, the immune function is reduced, and the disease is more susceptible. .

(two) pathogenesis

Pseudomembranous enterocolitis is a disease mediated by Clostridium difficile toxins, and four species of toxins can be produced by Clostridium difficile: A toxin (enteric toxin), B toxin (cytotoxin), peristaltic change factor and Unstable factors, A toxin and B toxin are closely related to the pathogenesis of PMC. They are all macromolecular protein exotoxins. It has been confirmed that human intestinal mucosa is sensitive to both A and B toxins of Clostridium difficile. Among them, A toxin can activate macrophages, mast cells and neutrophils release potent inflammatory mediators and cytokines, which cause intestinal mucosal inflammatory cell infiltration, hemorrhage and villus damage, and can cause extensive intestinal mucosa in severe cases. Necrosis, B toxin can only aggravate intestinal mucosal lesions on the basis of A toxin and has no direct effect on mucosa. It has been confirmed that there is A toxin-specific glycoprotein receptor on intestinal mucosa, and A toxin passes through receptors. Binding into the cells causes the cells to swell and increase permeability.

Pseudomembranous enterocolitis mainly invades the colon (the most common sigmoid colon), sometimes involving the small intestine (most common at the end of the ileum), and the involvement of the colon and small intestine is relatively rare. The pathological changes of PMC are classified into three categories: mild lesions including mucosa Focal necrosis of polymorphonuclear granulocyte infiltration and eosinophil exudation; inflammatory cell infiltration in moderate lesions is often limited to the superficial part of the lamina propria, where glandular destruction, typical pseudomembrane formation but lesions The mucosa in the middle is normal; the lamina propria is extensively damaged and necrotic in severe lesions, which are covered with a thick and fused pseudomembrane.

Prevention of pseudomembranous enterocolitis in the elderly

Because the application of antibiotics is the main cause of pseudomembranous enterocolitis, and regardless of the antibiotics used, the dose and the length of treatment can induce the disease. Therefore, elderly patients should try to avoid the use of antibiotics, especially broad-spectrum antibiotics. Narrow-spectrum antibiotics may be used when they are used. Once the PMC is suspected, the relevant antibiotics should be stopped immediately. In addition, the elderly should strengthen their exercise and enhance their body resistance.

Complications of pseudomembranous enterocolitis in the elderly Complications, paralytic ileus, shock, disseminated intravascular coagulation

Severe patients can produce various complications, such as toxic megacolon, paralytic ileus, intestinal perforation, intestinal hemorrhagic shock, DIC, etc., and the mortality rate is as high as 20%.

Elderly pseudomembranous colonic inflammation symptoms common symptoms fatigue toxemia peritoneal irritation high fever dull pain abdominal pain diarrhea pain dizziness watery stool

Pseudomembranous enterocolitis can occur in all age groups, but most (more than 60%) of the patients are elderly, slightly more women than men, patients often have some basic lesions, such as intestinal obstruction, inflammatory bowel disease After gastrointestinal surgery and various critically ill patients, and a large number of short-term application of broad-spectrum antibiotic history, rapid onset, rapid development, the main clinical manifestations of diarrhea, abdominal pain, fever, water and electrolyte disorders and acid-base imbalance, severe cases Shock and various complications have occurred.

1. Diarrhea: Patients with pseudomembranous enterocolitis have diarrhea, mostly watery, and the amount is large (>1L/d). In severe cases, the membrane can be discharged with different sizes, up to 10 A few centimeters, a small number of patients with severe conditions can be mushy, mucous and pus-like stools.

2. Abdominal pain: The pain area is mostly located in the shame area. The pain is dull pain, pain or cramping pain. The patient's abdomen generally has no obvious tenderness, rebound tenderness, and occasional peritoneal irritation.

3. Fever: moderate or high fever is common, accompanied by symptoms of toxemia such as dizziness and fatigue.

4. Water, electrolyte imbalance and acid-base imbalance: severe diarrhea leads to the loss of a large amount of water and salt. If it is not replenished in time, water, electrolyte imbalance and acid-base imbalance can occur. In severe cases, shock can occur.

Examination of pseudomembranous enterocolitis in the elderly

1. Bacterial culture: cultured in an anaerobic environment at 37 °C for 24 to 48 hours, the culture results are positive, and toxin identification should be carried out. Because a few normal people can carry Clostridium difficile, this strain does not produce toxins.

2. Toxin identification: In order to diagnose the gold standard of pseudomembranous enterocolitis, the tissue cell culture method is mainly used. This method is the most sensitive and specific, but the clinical implementation is difficult. The enzyme-linked immunosorbent assay (ELISA) is not sensitive to cell culture. But fast, simple, and economical, it is now used in the clinic.

3. Anti-toxin neutralization test: The mechanism is that the cytotoxic effect of the Clostridium difficile toxin can be neutralized by the anti-toxin of Clostridium difficile, and the anti-toxin can be neutralized and then neutralized at room temperature or 37 °C.

4. Endoscopy: A rapid and reliable method for the diagnosis of pseudomembranous enterocolitis, PMC can be divided into 3 types under endoscopy:

1 colitis-like type: visible mucosal congestion, edema, non-specific colitis-like manifestations, more common in patients with mild disease, early course of disease, timely treatment;

2 light type: still with mucous membrane congestion, edema mainly, visible pseudomembrane, white spotted, jumping distribution, surrounded by red halo, normal mucous membrane between red, more common in the early stages of the disease;

3 heavy: visible many patchy or map-like pseudomembrane, pseudo-film is yellow, yellow-white or yellow-brown, not easy to peel, easy to detach after peeling off or falling off, its peeling surface is similar to the endoscopic performance of erosive gastritis, more common in Patients with severe illness, advanced disease, and untimely treatment.

5. X-ray examination: abdominal X-ray plain film can be seen colonic dilatation, intestinal effusion and finger indentation, double contrast of gastroenterology enema shows colonic mucosal disorder, the edge is brush-like and there are many round or irregular knots on the mucosal surface. There are also signs of indentation and ulceration.

Diagnosis and diagnosis of pseudomembranous enterocolitis in the elderly

diagnosis

All patients with critical illness, after surgery, elderly patients with chronic diseases, especially after receiving high-dose antibiotics, sudden diarrhea, abdominal pain, should consider pseudomembranous enterocolitis, such as stool for watery stool, accompanied by fever and other symptoms The disease should be highly suspected, and the final diagnosis depends on the pathogen and histological examination.

Differential diagnosis

The disease should be differentiated from inflammatory bowel disease, surgical acute abdomen, etc. The identification points include antibiotic application history, endoscopy, pathological examination and toxin test.

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