Acute appendicitis

　　(1) Obstruction: The appendix is a slender tube, connected to the cecum at only one end. Once obstructed, it can cause the secretion in the lumen to accumulate, increasing the internal pressure, and compress the appendix wall to obstruct blood flow to the distal part. On this basis, bacteria in the lumen can easily enter the damaged mucosa, leading to infection. Obstruction is a common basic factor in the onset of acute appendicitis.

　　(2) Infection: The main factor is direct infection caused by bacteria in the appendix lumen. Since the appendix communicates with the cecum, it has the same species and quantity of bacteria, mainly Escherichia coli and anaerobic bacteria, as the cecum lumen. If the appendix mucosa is slightly damaged, bacteria can enter the wall, causing infections of varying degrees.

　　(3) Other: Factors considered to be related to the onset include visceral neuropathic reflexes caused by gastrointestinal dysfunction such as diarrhea and constipation, leading to spasm of appendiceal muscles and blood vessels. Once the intensity exceeds the normal level, it can cause appendiceal lumen stenosis, blood supply obstruction, mucosal damage, bacterial invasion, and acute inflammation. In addition, the onset of acute appendicitis is related to dietary habits, constipation, and genetic factors.

　　(1) Peritonitis

　　Limited or diffuse peritonitis is a common complication of acute appendicitis, and its occurrence and development are closely related to appendiceal perforation. Perforation occurs in gangrenous appendicitis, but it can also occur in the late course of suppurative appendicitis.

　　(2) Formation of abscess

　　It is the consequence of appendicitis not treated in a timely manner, and the most common abscess formed around the appendix. Abscesses can also form in other parts of the abdominal cavity. Common locations include the pelvis, subdiaphragmatic area, or intestinal spaces, etc.

　　(3) Formation of internal and external fistulas

　　If the surrounding abscess of appendicitis is not drained in time, it can break through to the intestines, bladder, or abdominal wall, forming various internal or external fistulas.

　　(4) Suppurative portal vein inflammation

　　Infections thrombi in the appendiceal veins can extend along the superior mesenteric vein to the portal vein, causing portal vein inflammation, which can then lead to liver abscess.

　　(1) Abdominal pain: The typical initial pain of acute appendicitis is located in the middle or upper abdomen or around the umbilicus, and after a few hours, the pain shifts and becomes fixed in the lower right abdomen. In the early stage, it is a visceral neuropathic reflex pain, so the pain in the middle or upper abdomen and around the umbilicus is more diffuse and often cannot be precisely localized. When the inflammation spreads to the serosal layer and parietal peritoneum, the pain becomes fixed in the lower right abdomen, and the original pain in the middle or upper abdomen or around the umbilicus diminishes or disappears. Therefore, the absence of a typical history of shifting right lower abdominal pain does not exclude acute appendicitis.

　　(2) Gastrointestinal symptoms: The gastrointestinal symptoms of simple appendicitis are not prominent. In the early stage, nausea and vomiting may occur due to reflexive gastric spasm. Pelvic appendicitis or appendiceal gangrene perforation may result in increased frequency of defecation.

　　(3) Fever: Generally, there is only low fever without chills, and the suppurative appendicitis does not usually exceed 38°C. High fever is more common in appendiceal gangrene, perforation, or concurrent peritonitis. Chills and jaundice suggest the possibility of concurrent suppurative portal vein inflammation.

　　(4) Palpation and rebound tenderness: Abdominal palpation is a manifestation of inflammation stimulating the parietal peritoneum. The appendiceal palpation point is usually located at McBurney's point, that is, the middle and outer 1/3 intersection of the line connecting the anterior superior iliac spine and the umbilicus. With the variation of the appendiceal anatomical position, the palpation point may change accordingly, but the key is that there is a fixed palpation point in the lower right abdomen. Rebound tenderness is also known as the Blumberg sign. In patients with obesity or appendicitis retrocecal, palpation may be mild, but there is marked rebound tenderness.

　　(5) Abdominal muscle tension: This sign is present when the appendix becomes suppurative. Abdominal muscle tension is particularly marked when there is gangrene and perforation with peritonitis. However, in elderly or obese patients, the abdominal muscles are weaker, and a simultaneous check of the contralateral abdominal muscles is necessary for comparison to determine whether there is abdominal muscle tension.

　　(6) Skin hypersensitivity: In the early stage, especially when there is an obstruction in the appendix, there may be a phenomenon of skin hypersensitivity in the lower right abdomen. The range is equivalent to the 10th to 12th thoracic spinal nerve distribution area, located in the triangle formed by the highest point of the right iliac crest, the right pubic crest, and the umbilicus, also known as the Sherren triangle. It does not change with the position of the appendix. If the appendix becomes gangrenous and perforates, the phenomenon of skin hypersensitivity in this triangle area will disappear.

　　(1) Avoid irregular eating habits and strenuous exercise after meals, and develop good defecation habits.

　　(2) In the early stage, light diet can be given according to appetite and condition.

　　(3) Rest in bed or in a semi-sitting position.

　　(4) After the symptoms of conservative treatment disappear, it is still necessary to continue taking medication.

　　(1) Blood routine: The white blood cell count of patients with acute appendicitis increases, accounting for about 90% of patients and is an important basis for clinical diagnosis. Generally, it is (10-15)×10^9/L. As the inflammation worsens, the white blood cell count also increases, and it can exceed 20×10^9/L. However, the white blood cell count may not increase in patients who are elderly, weak, or have suppressed immune function. At the same time with the increase in white blood cell count, the number of neutrophils also increases (about 80%). Both often appear simultaneously, but the significant increase in the proportion of neutrophils has the same important significance. When the condition is worsening and symptoms are deteriorating, a sudden decrease in the number of increased white blood cells is often a sign of sepsis, which is a critical condition that should be paid attention to.

　　(2) Urinalysis: The urine examination of patients with acute appendicitis is not special, but to exclude urinary system diseases with similar symptoms to appendicitis, such as renal calculus, it is still necessary to perform routine urine tests. Occasionally, the distal end of the appendix may have inflammation that is adherent to the ureter or bladder, and a small amount of red and white blood cells may appear in the urine, which should not be confused with calculus.

　　(3) Ultrasound examination: This examination was first applied for the diagnosis of acute appendicitis in the 1980s. It uses a pressure detection method to push away the intestinal gas around the appendix while maintaining the shape of the appendix. The congestion, edema, and exudation of the appendix are displayed as hyperechoic tubular structures with a relatively rigid appearance in the ultrasound image. The transverse section shows a target-like shadow in a concentric circle pattern. The diameter ≥7mm is a typical image of acute appendicitis with an accuracy rate of 90% to 96%. The sensitivity and specificity are also around 90%. However, when gangrenous appendicitis or inflammation has spread to peritonitis, a large amount of peritoneal effusion and intestinal paralysis and distension can affect the display rate of ultrasound. Ultrasound examination can also show appendicitis posterior to the cecum because the spasmodic cecum acts as a sonolucent window, making the appendix visible. Ultrasound examination can also play an important role in differential diagnosis because it can show conditions such as renal calculus, ovarian cysts, ectopic pregnancy, mesenteric lymphadenopathy, and so on. Therefore, it is particularly useful for the diagnosis and differential diagnosis of acute appendicitis in women.

　　(4) Laparoscopic examination: This examination is one of the most definitive diagnostic methods for acute appendicitis because it allows direct observation of the appendix to determine if there is inflammation by inserting a laparoscope through the lower abdomen. It can also distinguish between other diseases that have similar symptoms to appendicitis. It can not only play a decisive role in confirming the diagnosis but can also be used for simultaneous treatment.

　　(1) Fluid diet should be provided, such as milk, soy milk, rice gruel, meat soup, etc., or semi-liquid diet, such as congee, soft noodles, etc. If preparing for hospital surgery, fasting and water restriction should be performed.

　　(2) Prohibit drinking alcohol, avoid eating raw, cold, spicy food, and difficult-to-digest food such as hard food, which can increase the burden on the intestines and lead to indigestion and dysfunction of the gastrointestinal tract. Eat less fried and difficult-to-digest food.

　　(3) Do not overeat or undereat: Irregular diet can lead to abnormal filling and emptying of the gastrointestinal tract; overeating and undereating can suddenly increase the burden on the gastrointestinal tract and increase the mechanical stimulation of food. This can change the normal peristalsis of the intestines and lead to dysfunction.

　　(4) Adjust the diet structure, eat more vegetables and less meat; eat more soft food and less hard food. Eat less spicy and greasy food, chew slowly, and reduce the residue of food entering the cecum. Eat more vegetables and fruits. Appropriately supplement nutrition and strengthen physical exercise.

　　(5) Prevent overfatigue. Because overfatigue can reduce the body's ability to resist diseases and lead to a sudden aggravation of the condition.

　　(6) Drink an appropriate amount of water. It can neutralize stomach acid, reduce the stimulation of gastric juice on the ulcer surface, and at the same time, it can supplement mild dehydration caused by diarrhea.

　　(7) Use drugs with caution, especially some antipyretic and analgesic drugs and anti-inflammatory drugs, which have a large impact on the gastrointestinal tract and can cause gastrointestinal bleeding or perforation in severe cases. It is best not to use them or use them sparingly.

　　(I) Treatment Principles

　　1. Acute simple appendicitis: If conditions permit, combined non-surgical treatment of traditional Chinese and Western medicine can be carried out first, but it must be carefully observed, and if the condition develops, timely transfer to surgery should be considered. After conservative treatment, there may be stricture of the appendiceal lumen, and there is a high chance of recurrence.

　　2. Empyema and perforated appendicitis: In principle, emergency surgery should be performed immediately to remove the pathological appendix, and postoperative active anti-infection and prevention of complications should be carried out.

　　3. Appendicitis with inflammatory mass after several days of onset: Temporary conservative treatment should be given to promote the rapid resorption of inflammation. If symptoms persist after 3-6 months, appendectomy should be considered. If there is an expansion of abscess and possible rupture during the conservative period, emergency drainage should be performed.

　　4. Elderly patients, children, and acute appendicitis during pregnancy should, in principle, undergo emergency surgery like adult appendicitis.

　　(II) Non-surgical Treatment:Mainly suitable for acute simple appendicitis, appendiceal abscess, early and late pregnancy acute appendicitis, and appendicitis in elderly patients with major organ diseases.

　　1. Basic Treatment: Including bed rest, diet control, appropriate fluid replacement, and symptomatic treatment.

　　2. Antimicrobial Treatment: Broad-spectrum antibiotics (such as ampicillin) and drugs against anaerobic bacteria (such as metronidazole) should be selected.

　　3. Acupuncture Treatment: Acupoints such as Zusanli and appendiceal point can be selected, with strong stimulation, needles retained for 30 minutes, twice a day, for three consecutive days.

　　4. Traditional Chinese Medicine Treatment: It can be divided into external application and internal administration.

　　(1) External Application: Suitable for appendiceal abscess. For example, the Four Yellow Powder: equal parts of rhubarb, coptis, scutellaria and phellodendron, appropriate amount of borneol, finely ground and mixed with warm water to form a paste for external application.

　　(2) Oral administration: The main function is to clear heat and detoxify, promote Qi and activate blood, and purge the interior. According to the principle of traditional Chinese medicine diagnosis and treatment, acute appendicitis is divided into three stages, and the main formulas for each stage are selected.

　　① Stagnation stage: Use the Appendicitis Blood-Activating Decoction - the main ingredients include fructus magnolia, Corydalis yanhusuo, moutan bark, peach kernel, costus, lonicera japonica, and rhubarb, etc.

　　② Retention of heat stage: Use the Appendicitis Purification Decoction - the main ingredients include lonicera japonica, dandelion, moutan bark, rhubarb, fructus magnolia, red peony, peach red, and raw licorice, etc.

　　③ Toxic heat stage: Use the Appendicitis Detoxification Decoction - the main ingredients include lonicera japonica, dandelion, rhubarb, winter melon seeds, moutan bark, costus, fructus magnolia, and raw licorice, etc.

　　(Three) Surgical treatment:Mainly suitable for various acute appendicitis, recurrent chronic appendicitis, patients with appendiceal abscess who still have symptoms after conservative treatment for 3-6 months, and those who are ineffective with non-surgical treatment.

　　1. Preoperative preparation: No food or drink should be taken 4-6 hours before surgery. Adequate analgesics can be given after determining the surgery time, and broad-spectrum antibiotics should be administered to those who have become purulent or perforated. For patients with extensive peritonitis, gastroenteric decompression, intravenous fluid infusion, and attention should be paid to correcting water and electrolyte imbalances. For patients with dysfunction of the main organs such as the heart and lungs, appropriate treatment should be carried out in cooperation with relevant departments.

　　2. Surgical method: It is most appropriate to complete the operation under local anesthesia through a right lower quadrant oblique incision. A few patients can also choose epidural anesthesia and general anesthesia through a right lower quadrant exploratory incision. The main method is appendectomy (including routine and retrograde methods). The subserosal resection of the appendix can also be performed in severe adhesions. In cases where conservative treatment for appendiceal abscess is ineffective, incision and drainage can be performed, and drainage items can be placed when there is a lot of peritoneal effusion.

　　3. Postoperative management: Continue supportive treatment, including intravenous fluid infusion, analgesic sedation, and anti-infection, etc. The drain should be removed in a timely manner, the incision should be sutured on schedule, and attention should be paid to the prevention and treatment of various complications.

　　4. Prevention and treatment of postoperative complications: There is a close relationship between postoperative complications and the pathological type of appendicitis and the timing of surgery. The incidence of complications after the excision of non-perforated appendicitis is only 5%, while it increases to more than 30% after perforation. The rate of appendiceal perforation is 20% and 70% respectively for those operated on 24 hours and 48 hours after onset. Therefore, the appendix should be removed immediately within 24 hours of onset to reduce the incidence of complications.