What Is Acute Appendicitis?

Acute appendicitis is a common surgical disease and ranks first among all kinds of acute abdomen. Metastatic right lower quadrant pain, tenderness of the appendix, and rebound tenderness are common clinical manifestations, but the condition of acute appendicitis varies widely. Its clinical manifestations are persistently accompanied by paroxysmal exacerbation of right lower quadrant pain, nausea, and vomiting. Most patients have increased white blood cell and neutrophil counts. Tenderness in the right lower abdomen appendix (Mc's point) is an important sign of the disease. Acute appendicitis is generally divided into four types: acute simple appendicitis, acute suppurative appendicitis, gangrene and perforating appendicitis, and periappendic abscess.

Basic Information

English name

acute appendicitis

Visiting department

General surgery

Common causes

Caused by appendix lumen stenosis, impaired blood supply, or bacterial infection

Common symptoms

Right lower quadrant pain, nausea, and vomiting with metastatic exacerbation

Causes of acute appendicitis

Obstruction

The appendix is a slender tube with only one end communicating with the cecum. Once obstructed, the lumen secretion accumulates and the internal pressure increases, compressing the wall of the appendix and hindering distal blood flow. On this basis, bacteria in the lumen invade the damaged mucosa and easily cause infection. Obstruction is a common basic factor in the incidence of acute appendicitis.

2. infection

The main factor is the direct infection caused by bacteria in the appendix. Because the appendix is connected to the cecum, it has the same species and quantity of E. coli and anaerobic bacteria as the cecum. If the appendix mucosa is slightly damaged, bacteria invade the wall of the tube and cause different degrees of infection.

3. Other

Among the other factors considered to be related to morbidity are visceral nerve reflexes due to gastrointestinal dysfunction such as diarrhea and constipation, causing appendix muscles and vasospasm. Once it exceeds normal intensity, it can produce appendix lumen stenosis, impaired blood supply, and mucosa Damage, bacterial invasion and acute inflammation. In addition, the incidence of acute appendicitis is related to factors such as diet, constipation and heredity.

Classification of acute appendicitis

Acute simple appendicitis

For early appendicitis, the lesions are more severe in the appendix or submucosa. The appendix is slightly swollen, the serosa surface is congested, and the normal luster is lost. Mucosal epithelium may show one or more defects, with neutrophil infiltration and cellulose exudation. There are inflammatory edemas in the submucosa.

2. Acute Cellulitis Appendicitis

Also known as acute suppurative appendicitis, it often develops from simple appendicitis. The appendix was swollen significantly, the serosa was highly congested, and the surface was covered with cellulose exudates. Under the microscope, the inflammatory lesions were fan-shaped and extended from the superficial layer to the deep layer, reaching the muscle layer and serosa layer. Each layer of the appendix wall is diffusely infiltrated with a large number of neutrophils, and has inflammatory edema and cellulose exudation. The surface of the appendix serosa is covered with a thin film composed of exuding cellulose and neutrophils, which shows signs of appendicitis and local peritonitis.

3. Acute gangrenous appendicitis

It is a severe appendicitis. Appendiceal obstruction, empyema, increased intraluminal pressure, and thrombophlebitis caused by inflammation of the mesangial vein of the appendix can cause blood circulation disorders in the appendix wall, leading to necrosis of the appendix. At this time, the appendix is dark red or black, often leading to perforation, causing diffuse peritonitis or an abscess around the appendix.

Clinical manifestations of acute appendicitis

Abdominal pain

Typical acute appendicitis has mid-upper abdomen or periumbilical pain in the early stage. After a few hours, abdominal pain is transferred and fixed in the right lower abdomen. In the early stage, it is a kind of visceral nerve reflex pain, so the range of pain in the middle and upper abdomen and umbilical cord is diffuse, and it is often impossible to determine the exact location. When inflammation spreads to the serosal layer and parietal peritoneum, the pain is fixed in the right lower abdomen, and the original middle and upper abdomen or umbilical pain is reduced or disappeared. But the absence of typical metastatic right lower quadrant pain does not rule out acute appendicitis.

Simple appendicitis often presents as paroxysmal or persistent tenderness and dull pain, and persistent severe pain is often indicated as purulent or gangrenous appendicitis. Sustained severe pain affects the mid-lower abdomen or both sides of the lower abdomen, often with signs of perforating appendix gangrene. Sometimes the appendix gangrene is perforated and abdominal pain is relieved. However, this pain relief phenomenon is temporary, and other accompanying symptoms and signs have not improved or even intensified.

2. Gastrointestinal symptoms

Gastrointestinal symptoms of simple appendicitis are not prominent. In the early stage, nausea and vomiting may be caused by reflex gastric cramps. Pelvic appendicitis or perforation of appendic gangrene may have increased bowel movements.

3. Fever

Generally only low fever, no chills, purulent appendicitis generally does not exceed 38 ° C. High fever is more common in appendic gangrene, perforation or peritonitis. Accompanied by chills and jaundice, suggest that purulent portal vein inflammation may be complicated.

4. Tenderness and rebound pain

Abdominal tenderness is a manifestation of inflammation of the parietal peritoneum. The appendix tenderness point is usually located at Mai's point, that is, at the junction of the middle and outer 1/3 of the line connecting the anterior superior palate and the umbilicus. With the variation of the anatomical position of the appendix, the tenderness point may change accordingly, but the key is that there is a fixed tenderness point in the right lower abdomen. Bounce back pain is also called Blumberg sign. In obese or posterior appendicitis patients, tenderness may be mild, but there is a marked rebound tenderness.

5. Abdominal muscle tension

Appearance of appendic suppuration is this sign. Abdominal muscle tension is particularly significant when gangrene perforation is accompanied by peritonitis. However, the abdominal muscles of elderly or obese patients are weak, and the contralateral abdominal muscles must be checked at the same time to determine whether there is abdominal muscle tension.

6. Skin Allergy

In the early stage, especially when there is an obstruction in the appendix cavity, skin hypersensitivity may occur in the right lower abdomen. The range is equivalent to the innervation zone of the thoracic segment of the 10th to 12th. The area, also known as the Sherren triangle, does not change due to different appendix positions. For example, perforation of the appendix gangrene disappears in this triangle.

Acute appendicitis examination

Blood routine

Patients with acute appendicitis have an increased white blood cell count, which accounts for about 90% of patients, which is an important basis for clinical diagnosis. Generally it is (10 ~ 15) × 10 ⁹ / L. As the inflammation worsens, the number of white blood cells increases, which can even exceed 20 × 10 ⁹ / L. However, in elderly patients who are frail or whose immune function is suppressed, the number of white blood cells may not increase. At the same time as the number of white blood cells increased, the number of neutrophils also increased. The two often appear at the same time, but there is also a significant increase in only neutrophils, which is of equal significance.

2. Urine routine

There is no special urine test for patients with acute appendicitis, but routine urine tests are still necessary to rule out urinary system diseases like appendicitis. Occasionally, there is inflammation of the distal appendix and adhesion to the ureter or bladder. A small amount of red and white blood cells may also appear in the urine.

3. Ultrasound

Appendicum congestion, edema, exudation, low-echo tubular structure in the ultrasound display, relatively stiff, its cross-section shows a target-like development of concentric circles, diameter 7mm, is a typical image of acute appendicitis. However, when gangrenous appendicitis or inflammation has spread to peritonitis, a large amount of abdominal exudate and intestinal paralysis can affect the display rate of ultrasound. Ultrasonography can show retrocecal appendicitis, because the appendix is shown because of the convulsive cecum. Ultrasound can also play an important role in differential diagnosis, because it can show ureteral stones, ovarian cysts, ectopic pregnancy, mesenteric lymphadenopathy, etc., so it is particularly useful for the diagnosis and differential diagnosis of acute appendicitis in women.

4. Laparoscopy

This test is one of the methods that can get the most positive results in the diagnosis of acute appendicitis. Because the insertion of a laparoscope through the lower abdomen can directly observe the presence or absence of inflammation of the appendix, it can also distinguish other adjacent diseases with similar symptoms to appendicitis, which not only plays a decisive role in determining the diagnosis, but also can be treated simultaneously.

Diagnosis of acute appendicitis

Colonic inflation test

When the patient is in the supine position, the left lower abdomen is compressed with the right hand, and the proximal colon is squeezed with the left hand. The gas in the colon can be transmitted to the cecum and the appendix, causing positive pain in the right lower abdomen.

2. Psoas major test

The patient was placed in the left side and the right thigh was extended backward, causing pain in the right lower abdomen. This indicates that the appendix is located in front of the psoas major muscle, posterior cecum or retroperitoneum.

3. Obturator intramuscular test

The patient took a supine position, flexed the right hip and right thigh, and then passively turned inward. Those who caused pain in the right lower abdomen were positive. Tip the appendix near the obturator muscle.

4. Characteristics of pediatric acute appendicitis

(1) The condition develops rapidly and severely, with high fever and vomiting occurring early.

(2) The signs of the right lower abdomen are not obvious, but there are obvious local tenderness and muscle tension.

(3) The perforation rate is high and the complications are high.

Complications of acute appendicitis

Peritonitis

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

2. Abscess formation

It is the consequence of untreated appendicitis. Appendiceal abscesses formed around the appendix are the most common. Abscesses can also be formed in other parts of the abdominal cavity. Common parts include pelvic cavity, subcondylar or intestinal space.

3. Internal and external fistula formation

If the abscess around the appendix is not drained in time, it can penetrate to the intestinal tract, bladder, or abdominal wall to form various internal or external fistulas.

4. Purulent portal phlebitis

Infectious thrombi in the appendix vein can travel from the superior mesenteric vein to the portal vein, leading to portal phlebitis, which in turn can form a liver abscess.

Acute appendicitis treatment

Non-surgical treatment

(1) When acute appendicitis is in the early stage of simple inflammation, antibiotic anti-infection treatment can be used. Once the inflammation absorption subsides, the appendix can return to normal. When the diagnosis of acute appendicitis is clear and there are indications for surgery, but because of the patient's overall situation or objective conditions, non-surgical treatment can be taken first to delay the operation. If acute appendicitis has been combined with localized peritonitis and an inflammatory mass has formed, non-surgical treatment should also be used to absorb the inflammatory mass, and then elective appendectomy is considered.

(2) General treatment Mainly bed rest, fasting, intravenous water and electrolytes.

(3) Antibiotics The majority of appendicitis is a mixed infection. Ampicillin (ampicillin), gentamicin and metronidazole are used in combination, which has a good effect.

(4) Application of analgesics Applicable to patients who have decided on surgery, but banned in general, especially the frail.

(5) Symptomatic treatments such as sedation, antiemetic, and gastric decompression tube if necessary.

2. Surgical treatment

In principle, acute appendicitis should be treated with appendectomy except that the mucosal edema type can be cured after conservative treatment.