Pediatric acute appendicitis

　　1. Etiology

　　The etiology of pediatric acute appendicitis is complex, and it is still not fully understood. It is related to the following factors:

　　1. Appendiceal lumen obstruction Secretions accumulate, increasing intraluminal pressure, impeding blood supply to the appendiceal wall, which is conducive to bacterial invasion. The most common cause of obstruction is fecal calculus, foreign bodies (fruit seeds, worms), appendiceal torsion, and luminal scar stenosis, etc.

　　2. Bacterial infection Bacteria can reach the appendix through broken or damaged mucosa and the blood circulation, causing acute inflammation, such as pharyngitis, upper respiratory tract infection, tonsillitis, etc.

　　3. Nerve reflex When gastrointestinal function is impaired, there is often reflex spasm of the appendiceal muscle and blood vessels, leading to obstruction of the appendiceal lumen and circulatory disturbances, causing inflammation.

　　2. Pathogenesis

　　According to the different pathological development processes, it can be divided into 3 types:

　　1. Catarrhal (simple) appendicitis primarily presents with mucosal congestion and edema, infiltration of neutrophils.

　　2. Purulent (phlegmonous) appendicitis involves not only mucosal lesions but also invasion of the seromuscular layer, with purulent exudates attached. Abdominal peritoneal infection and exudation can occur early, and perforation may develop as the condition progresses.

　　3. Gangrenous appendicitis involves rapid vasoconstriction and thrombosis after appendiceal infection, leading to circulatory disturbances. The appendiceal wall rapidly undergoes extensive necrosis, appearing dark purple with minimal exudation. However, it quickly infiltrates surrounding tissues, leading to adhesions. The catarrhal appendicitis lesion is limited to the mucosa and can be cured with conservative treatment. However, it may also transform into purulent appendicitis due to poor appendiceal lumen drainage and secondary infection. Early surgical treatment is recommended for all confirmed cases of purulent and gangrenous appendicitis. The younger the child, the shorter the omentum, the thinner the appendiceal wall, and the more prone to perforation. Additionally, the limited ability to contain the infection can lead to diffuse peritonitis. Moreover, due to the higher and relatively mobile position of the cecum in children, the site of tenderness can vary greatly.

　　What diseases can acute appendicitis in children be complicated with?

　　1. Residual abscess After appendiceal perforation and peritonitis, the occurrence of residual abscess is a severe complication. The abscess is often localized in the pelvic cavity, intestinal spaces, subdiaphragmatic or intrahepatic, subsplenic areas, with pelvic abscess being the most common. It forms 7-14 days after surgery. Clinical manifestations include a temporary drop in body temperature followed by a gradual rise, increased white blood cells. For such patients, anti-inflammatory and supportive therapy is often used to allow the pus to be absorbed spontaneously. When the abscess is large, the location is clear, and there is tension, puncture drainage or surgical incision drainage can be performed under B-ultrasound guidance.

　　2. Adhesive intestinal obstruction often occurs in patients with appendiceal perforation peritonitis or abscess, due to inflammation causing adhesion between intestinal loops and mesentery, which can lead to intestinal obstruction. Early intestinal obstruction (within 10 days after surgery) is often related to infection. After conservative treatment, gastrointestinal decompression, and active control of infection, obstruction can usually be relieved. In cases of late intestinal obstruction (after 1 month), if conservative treatment does not improve, laparotomy may be necessary.

　　3. Fecal fistula is often caused by severe lesions around the appendix or at the residual end of the appendix. Fecal fistula is rare in children, and some cases are due to tuberculosis infection. If the fistula does not heal after several weeks of dressing changes, appendiceal resection should be performed.

　　1. Clinical manifestations

　　1. Abdominal pain Due to difficulties in asking and narrating medical history, typical history of转移性腹痛 is often not obtained. Abdominal pain is widespread and sometimes not the initial symptom.

　　2. Gastrointestinal symptoms are often prominent, with vomiting as the initial symptom. The degree of vomiting is severe, and the duration is long. Dehydration and acidosis may occur due to excessive vomiting, preventing eating. Diarrhea may also occur, but constipation is rare. Diarrhea is caused by intestinal inflammation stimulating rapid peristalsis.

　　3. General symptoms are severe, with early onset of fever, which can reach 39-40°C, and even chills, high fever, convulsions, and seizures. This is due to the instability of the body temperature center in young children and intense inflammatory reactions.

　　4. Tenderness and muscle tension The tenderness points are usually above the McBurney point. The cecum in infants and young children is located high and has high mobility, so the tenderness points are more inward and upward. Children have thin abdominal walls and are not cooperative, making it difficult to judge whether there is muscle tension. It is necessary to check carefully, gently, and thoroughly, and compare the examination from top to bottom and left to right.

　　5. Abdominal distension and decreased bowel sounds are more prominent due to early peritoneal effusion, which inhibits gastrointestinal function.

　　6. Upper respiratory symptoms The incidence of upper respiratory tract infections in children is relatively high, and these diseases may be triggering factors for acute appendicitis. Therefore, children often have upper respiratory diseases first, followed by clinical manifestations of acute appendicitis.

　　2. Acute appendicitis in children has the following characteristics:

　　1. Children have weak body defense capabilities due to insufficient humoral immune function, complement deficiency, and poor phagocytic activity of neutrophils. Additionally, the instability of body temperature regulation leads to easy occurrence of high fever, significant increase in white blood cells compared to adults, and severe toxic symptoms.

　　2. The clinical symptoms of acute appendicitis in older children are similar to those in adults.

　　Infants under 6 years of age often lack typical symptoms of right lower quadrant pain, and abdominal pain and signs are often not fixed, so the rate of misdiagnosis in clinical practice is high, with some reports reaching 63%.

　　3. Purulent and perforated masses Children with acute appendicitis have abundant appendiceal lymphoid tissue, very thin appendiceal wall, and less muscular layer tissue. After inflammation, lymphedema is severe, which can cause appendiceal lumen obstruction and hemodynamic disorders, making it easy to perforate. The younger the age, the higher the incidence of perforation. After perforation, it often forms diffuse peritonitis, and it is difficult to form localized abscesses due to incomplete development of the omentum and rapid perforation. Purulent appendicitis can cause perforation within 14～24 hours of onset.

　　Since the etiology of pediatric acute appendicitis is not yet clear, prevention of appendicitis can be paid attention to from the following aspects:

　　1. Diet guide children to develop good eating habits, pay attention to dietary hygiene, wash hands before and after meals, and do not overeat.

　　2. Avoid activities while playing and eating, and avoid剧烈 movements such as running, jumping, and bouncing immediately after meals.

　　3. Deworming to prevent intestinal parasites, and timely follow the doctor's advice for deworming treatment.

　　4. Exercise can strengthen the physical fitness of children, enhance physical exercise, and prevent the occurrence of various diseases, such as actively preventing upper respiratory tract infection, measles, acute tonsillitis, and so on, which has a positive significance.

　　First, laboratory examination

　　1. Blood routine tests The total white blood cell count and neutrophils in purulent appendicitis increase, with the total white blood cell count reaching (10～12)×109/L; in purulent appendicitis, it can reach (12～14)×109/L; when abscess formation or diffuse peritonitis occurs, the white blood cell count can reach above 20×109/L, and the neutrophil count is 0.85～0.95, with nuclear left shift. If the neutrophil count increases to above 0.85, it mostly indicates a severe condition, and toxic granules may also be seen. However, in some cases, the white blood cell count in children with appendicitis may not increase significantly.

　　2. Urine and stool routine tests generally show no special changes. If the appendix is located near the ureter, there may be a small number of red blood cells in the urine, and a small number of pus balls may be present in the stool in severe cases.

　　3. It has been reported that in children with acute appendicitis, the serum C-reactive protein (CRP) level is significantly increased, and the plasma fibrinogen level is decreased. These two measurements can be used as auxiliary indicators for preoperative judgment of the severity of appendicitis.

　　4. For patients with suspected appendicitis and difficult diagnosis, especially those with symptoms of peritonitis, it can be attempted to puncture the abdomen, generally using a subcutaneous needle to puncture the right lower abdominal appendiceal point. The puncture fluid is then examined under a microscope, bacterial smears, and biochemical tests. If pus balls are observed under the microscope, it is mostly early purulent appendicitis; if the puncture fluid is thin, it is mostly early localized peritonitis; if the puncture fluid is abundant, thick, or bloody, with a fecal smell, and a large number of bacteria are seen in the smear, it is mostly gangrenous appendicitis, diffuse peritonitis, or periappendiceal abscess.

　　Second, Imaging examinations

　　1. Anorectal examination There is inflammatory infiltration and thickening in the right anterior rectum, and there is tenderness when there is an abscess in the pelvic cavity, with the formation of inflammatory masses.

　　2. X-ray abdominal film For cases with abdominal distension, X-ray examination can be performed. About 10% of cases can show appendiceal fecal calculus shadow. When appendicitis occurs, the film shows an abnormal gas shadow in the lower right abdomen, disappearance of the right abdominal wall line, blurred lumbar muscle shadow, and rightward curvature of the lumbar vertebrae, etc. X-ray imaging lacks specificity, but it is helpful to differentiate intestinal obstruction, gastrointestinal perforation, necrotizing enteritis, and other conditions.

　　3. CT examination Under CT, the appendix and surrounding soft tissues and inflammation can be directly displayed, with a detection rate of 13% to 60%. It is manifested as symmetrical thickening of the wall, complete occlusion or expansion filled with watery density pus, blurred fat around the cecum, and increased density.

　　4. Ultrasound examination Under ultrasound, the normal appendix does not show any image. When appendicitis occurs, the diameter of the appendix can be increased to varying degrees, and an appendicitis diagnosis can be confirmed when the diameter is ≥6mm. The width of the appendix lumen increases, showing the size of the perianal abscess. Gangrenous appendicitis can also show the amount of peritoneal exudate and the peristalsis of the intestinal tract around the appendix. At the same time, it can also make a correct diagnosis of ectopic appendix.

　　5. Abdominal wall electromyography examination Wang Wei determined the abdominal signs of appendicitis patients based on the amplitude of abdominal wall electromyography waves, and compared the examination to determine the presence and degree of muscle tension. The results showed that the electromyography amplitude increased slightly during the static phase of simple appendicitis; during the static phase of purulent appendicitis, the electromyography amplitude increased slightly, and a significant increase in electromyography amplitude could be seen when pressing the lower right abdomen. When appendicitis with perforation and peritonitis occurs, due to the presence of persistent muscle tension, the electromyography amplitude of the lower left and right abdominal regions is significantly increased during the static state.

　　6. Enterography examination Chen Xiaogai's research on enterography examination of children with acute appendicitis found that the voltage at the ileocecal region of children without peritonitis was significantly lower than that of the control group, and the enterography of children with peritonitis was lower than the normal control group in all parts. This change may be related to intraperitoneal inflammatory stimulation and weakened intestinal function. When the inflammation is limited to the appendix, the intestinal tract inflammation directly stimulates the ileocecal region, and the voltage in this region shows abnormality. When the inflammation progresses and becomes severe, the appendix becomes purulent, gangrenous, and perforated, the amount of peritoneal inflammatory exudate increases, and the entire intestine is affected to varying degrees. Therefore, on the enterography, the voltage of all parts is significantly reduced, lower than the normal control group, but there is no special change pattern in the severity of peritonitis through enterography.

　　Diet should be light and plain, avoiding spicy, dry, hot, greasy, and fried foods:

　　1. For patients with blood stasis syndrome, it is advisable to consume qi-promoting and blood-activating foods such as hawthorn, vinegar, rose, and tangerines.食疗方：Persimmon Kernel and Coix Seed Porridge.

　　2. For patients with damp-heat syndrome, it is advisable to consume cooling and diuretic foods such as mung beans, winter melons, and lilies.食疗方：Winter Melon Seed and Sophora Flavescent Root Decoction (boil winter melon seeds, Sophora Flavescent Root, and Licorice in water, then add honey to taste).

　　3. For patients with heat-toxin syndrome, it is advisable to consume cooling and detoxifying foods such as watermelons, winter melons, bitter gourds, and lotus root nodes.食疗方：Three Yellow Drink (Rhubarb, Scutellaria baicalensis, Phellodendron amurense, and sugar).

　　1. Drug Treatment

　　1. Prescription: Chishao 9g, Huangqin 30g, Danpi 9g, Dahuang 9g (added later). It is often used for catarrhal appendicitis.

　　2. Prescription: Taoren 9g, Lianqiao 15g, Yinhua 30g, Stir-fried Shanyao 9g, Stir-fried Zhaoci 9g, Huangqin 30g, Chishao 15g, Baisao 30g, Dahuang 9g (added later), Shengshi 30g (used when feverish). It is often used for appendiceal abscess.

　　3. Modification and Addition Method:

　　(1) Add Shengshi, Zixue, Renonghuang, and Daqingye for high fever.

　　(2) Add Huoxiang, Peilan, and Yimi for anorexia, damp-heat, and slippery coating.

　　(3) Add Zhuru, Shengjiang, and Shengbanxia for nausea and vomiting.

　　(4) Add Yuhan, Chuanglianzi, Taoren, and Chuanxiong for abdominal pain.

　　(5) Add Mangxiao and Yuanmingfen for constipation.

　　(6) Add Zhishi, Houpo, and Stir-fried Radish Seed for abdominal distension.

　　(7) Add Chaihu, Huangqin, and Jie sui for remittent fever.

　　2. Acupuncture Therapy

　　1. As an auxiliary treatment. The main acupoint is Zusanli or the appendicitis point, and other acupoints such as Shangwan, Tianchi, Hegu, etc., can be combined according to clinical symptoms.

　　2. Western medical treatment methods for pediatric acute appendicitis.

　　3. The basic treatment for pediatric acute appendicitis is early surgery, removing the appendix. For patients with simple appendicitis who have no deterioration after 1-2 days of conservative treatment, or for those with improving peritonitis, localized and forming appendiceal abscess, non-surgical treatment is adopted. However, if the body temperature rises during conservative treatment, the tension of the formed abscess increases, or the range of tenderness expands, immediate surgery is required. For purulent, gangrenous, and obstructive appendicitis within 3 days, early surgical treatment is recommended.

　　3. Non-Surgical Treatment

　　1. General Treatment:

　　Patients should rest in bed and be given liquid or semi-liquid food. If dehydration occurs due to anorexia, intravenous fluid should be administered to correct dehydration and electrolyte imbalance.

　　2. Drug Treatment:

　　Antibiotics are used to control Gram-positive, Gram-negative, and anaerobic 3 types of bacteria. Commonly used are penicillin, chloramphenicol, metronidazole, (gentamicin) and others.

　　4. Surgical Treatment

　　Before the operation, general symptoms need to be improved, such as correcting dehydration and electrolyte imbalance, antipyretic, antibiotic application, using gastrointestinal decompression to improve abdominal distension, etc. The operation mainly involves appendectomy. For abdominal abscess and necrotic tissue, abdominal drainage is performed at the same time. For severe local infiltration and adhesion, drainage is first performed, and then appendectomy is performed 2-3 months later.