Acute necrotizing enteritis

　　The etiology is not fully understood to date, and it may be a type of hypersensitivity reaction. Some people believe that it is related to Clostridium perfringens type C, which produces beta-toxin that can cause tissue necrosis and act on intestinal blood vessels, causing spasm and intravascular coagulation, leading to edema, hemorrhage, and necrosis of the mucosa and submucosa. Bacterial endotoxemia can cause non-specific hypersensitivity, leading to vascular lesions, exudation, and intravascular coagulation, resulting in the disease. Some children may have concurrent enterobiasis, and the worms can secrete trypsin inhibitors, which may be a triggering factor for the disease.

　　Acute necrotizing enterocolitis is an explosive abdominal infection disease, with an acute onset and rapid development, mainly characterized by abdominal inflammation, and its complications are as follows

　　1. Intestinal obstruction

　　Intestinal obstruction refers to the obstruction of the passage of intestinal contents, commonly referred to as an unsmooth intestine. Here, the intestine usually refers to the small intestine (jejunum, ileum) and colon (ascending colon, transverse colon, descending colon, sigmoid colon). Acute intestinal obstruction is one of the most common surgical acute abdominal conditions, which can often be encountered in the emergency room. Due to various reasons, the mortality rate is still relatively high, about 5% to 10%; if intestinal strangulation occurs, the mortality rate can rise to 10% to 20%. The main clinical symptoms of intestinal obstruction are abdominal pain, vomiting, bloating, and the cessation of排气 and defecation.

　　2. Shock

　　A syndrome caused by Staphylococcus aureus alpha-toxin, characterized by high fever, vomiting, confusion, and rash, which can quickly progress to severe and refractory shock.

　　3. Disseminated intravascular coagulation

　　The absorption of bacteria and endotoxins into the blood causes systemic toxic symptoms and hemodynamic disorders, leading to DIC symptoms. Disseminated intravascular coagulation (DIC) refers to the activation of coagulation factors and platelets under the action of certain pathogenic factors, with a large amount of soluble procoagulant substances entering the blood, thus causing a pathological process (or pathological syndrome) characterized by impaired coagulation function. A large number of microthrombi are formed in the microcirculation, while a large amount of coagulation factors and platelets are consumed. The secondary fibrinolytic process is enhanced, leading to clinical manifestations such as bleeding, shock, organ dysfunction, and anemia.

　　Acute necrotizing enterocolitis has an acute onset, with 1/3 of cases having a history of unclean eating. Clinically, it is characterized by acute abdominal pain, distension, vomiting, diarrhea, bloody stools, and systemic toxic symptoms. The typical symptoms are as follows:

　　1. Abdominal pain and distension are often sudden, persistent, and may worsen intermittently. The pain is usually located around the umbilicus or in the upper abdomen. Some patients may have diffuse abdominal pain, and the disease may initially present with mild distension, which then becomes more severe.

　　2. After the onset of vomiting and abdominal pain, nausea and vomiting may occur, with the vomit containing bile, coffee-like, or bloodwater-like substances.

　　3. The degree of diarrhea and bloody stools varies, with more than 10 times a day in severe cases. Depending on the location of the lesion, bleeding speed, the time the stool stays in the intestines, and the condition of intestinal peristalsis, the stool can be fresh blood, broth-like, jam-like, or black, often mixed with decomposed tissue and a special smell.

　　4. Systemic toxic symptoms due to the translocation of bacteria and endotoxins can cause systemic inflammatory response, leading to fever or hypothermia, drowsiness or irritability. If coma occurs, it often indicates a severe condition, with the appearance of multiple organ dysfunction and possibly intestinal necrosis.

　　5. The symptoms of infants and young children are atypical, and most infants develop the disease between 3 to 10 days after birth.

　　6. Physical examination shows abdominal distension and tenderness, and the peritoneal irritation sign can be presented at varying degrees due to inflammatory exudation, with the appearance of intestinal type and abdominal masses. In cases of intestinal necrosis or perforation, typical signs of peritonitis throughout the abdomen can be observed. For those with toxic shock, there are often unstable respiratory and circulatory systems, rapid breathing, low blood pressure, rapid heart rate, altered consciousness, and skin with petechiae-like spots.

　　Acute necrotizing enterocolitis is a type of food poisoning, which is an infection of the stomach and intestines caused by eating contaminated food. Its preventive measures include:

　　1. If the baby is on artificial feeding, all feeding utensils must be strictly disinfected;

　　2. The prepared food should be stored in the refrigerator, as the temperature inside is lower. Do not store warm food in thermoses or in places with high temperatures, because bacteria are prone to reproduce in large quantities under warm conditions, making food more susceptible to spoilage and increase the risk of gastrointestinal infections;

　　3. Pay special attention to hygiene when preparing food. Cutting boards, kitchen knives, bowls, and other utensils must be disinfected. It is best to use boiling water to iron or soak them in disinfectant solution. Food should also be washed with clean water, especially not to use rotten meat as raw material for food.

　　4. Any cooked food should not be stored in the refrigerator for more than two days. Although the refrigerator is a low-temperature environment, bacteria are still multiplying, just at a slower rate. Therefore, try to eat fresh food as much as possible.

　　5. When reheating food, make sure it is very hot and heated for a period of time, which can kill a large number of pathogenic bacteria causing gastroenteritis.

　　6. Wash the tableware in boiling water or soak it in disinfectant. After washing, it should be stored in a clean place to prevent mosquitoes from contacting it, so as not to bring bacteria into it, causing secondary contamination. Dry with napkins instead of using dish towels.

　　1. Abdominal X-ray film The X-ray findings are related to the severity of AHNE. In the early stage, most cases may show varying degrees of intestinal lumen inflation and mild widening of the intestinal space. Due to edema and inflammatory exudation of the intestinal mucosa, the inner edge of the intestinal wall becomes blurred. With the progression of the disease, the image of intestinal wall gas accumulation can be found, which is generally believed to be caused by gas in the intestinal lumen passing through the damaged mucosa into the submucosa or peritoneal cavity. As the exudation increases, the intestinal space also widens. In the late stage, fixed and dilated loops of the intestines, portal vein gas, ascites, pneumoperitoneum, etc., are often present. Dynamic observation of abdominal intestinal loops on X-ray can often help in judging the viability of the intestines. Barium enema X-ray examination should be contraindicated during the acute stage as it may worsen bleeding or cause perforation.

　　2. Fiberoptic enteroscopy It can be used to detect early signs of intestinal inflammation and bleeding.

　　3. Ultrasound examination With the continuous accumulation of experience in gastrointestinal imaging, there is a trend to complement X-ray examination. Using this examination method will be more convenient and quick.

　　Patients with acute necrotizing enterocolitis should consume nutritious semi-liquid or soft food. Semi-liquid diet is a type of diet between soft rice and liquid. It is easier to chew and digest than soft rice. It contains very little fiber but sufficient protein and calories. Common semi-liquid foods include rice porridge, noodles in soup, mashed vegetables, cakes, etc.

　　During the recovery period, children must strictly control their diet. They can only start eating when the blood in stool and abdominal distension decrease, and occult blood in stool is negative. The diet should be restored from liquid (soup, milk, rice gruel) to semi-liquid (thin porridge) to soft food to normal diet. Parents should not give the child food prematurely due to hunger, even if there is still blood in stool and abdominal distension, as this often aggravates the condition and leads to repeated massive blood in stool, resulting in 'all efforts wasted'. During the period of diet restoration, closely observe the condition, and if there is recurrence, discontinue food intake again.

　　Acute necrotizing enterocolitis is mainly treated with non-surgical methods, emphasizing systemic supportive therapy to correct electrolyte and water imbalances, alleviate toxic symptoms, actively prevent toxic shock and other complications. Surgical treatment is only considered when necessary. The summary of treatment methods for acute necrotizing enterocolitis is as follows:

　　(I) Non-surgical treatment

　　1. General treatment: Rest, fasting. During the period of abdominal pain, hematochezia, and fever, complete bed rest and fasting should be maintained. During the period of fasting, high-nutrition fluids should be infused intravenously, such as 10% glucose, compound amino acids, and hydrolyzed protein, etc. For patients with severe abdominal distension and vomiting, gastrointestinal decompression can be performed. Antispasmodics can be given for abdominal pain.

　　2. Correcting electrolyte and water disorders This disease is more common with dehydration, sodium loss, and potassium loss. The total volume and composition of infusion can be determined according to the condition.

　　3. Anti-shock Rapidly replenish effective circulating blood volume. In addition to crystalloid solutions, appropriate amounts of plasma, fresh whole blood, or human serum albumin, etc., should be infused. For patients with unrisen blood pressure, vasoactive drugs can be used in conjunction with, such as α-receptor blockers, β-receptor agents, or atropine, etc., which can be selected according to circumstances.

　　4. Antibiotics The control of intestinal infection can alleviate clinical symptoms, and commonly used antibiotics include: ampicillin (4-8g/d), chloramphenicol (2g/d), gentamicin (160,000-240,000u/d), kanamycin (1g/d), sulbactam (6.0g/d), cefadroxil 4g/d, or polymyxin and cephalosporins, etc., generally two kinds are selected for combined use.

　　5. Adrenal cortical hormones Can alleviate toxic symptoms, suppress allergic reactions, and also help correct shock, but there is a risk of aggravating intestinal bleeding and triggering intestinal perforation, generally not more than 3-5 days.

　　6. Symptomatic therapy Severe abdominal pain can be treated with pethidine; patients with high fever and restlessness can be given oxygen inhalation, antipyretic drugs, sedatives, or physical cooling.

　　7. Antitoxin serum Welchii bacillus antitoxin serum 42000-85000u intravenous infusion has good efficacy.

　　(II) Surgical treatment

　　1. The following conditions can be considered for surgical treatment: ①Intestinal perforation; ②Severe intestinal necrosis with purulent or hemorrhagic effusion in the abdominal cavity; ③Repeated massive intestinal bleeding with hemorrhagic shock; ④Intestinal obstruction, intestinal paralysis. ⑤Other acute abdominal emergencies that cannot be ruled out and require urgent surgical treatment.

　　2. Surgical methods:

　　①For patients with no necrosis or perforation in the intestinal tract, a普鲁卡因intestinal mesentery block can be performed to improve the blood circulation of the lesion segment.

　　②For patients with severe lesions but limited localization, intestinal resection and anastomosis can be performed.

　　③For patients with intestinal necrosis or intestinal perforation, intestinal resection, perforation repair, or intestinal exteriorization can be performed.