Appendicitis


Appendicitis is inflammation of the appendix. Symptoms commonly include right lower abdominal pain, nausea, vomiting, fever and decreased appetite. However, approximately 40% of people do not have these typical symptoms. Severe complications of a ruptured appendix include widespread, painful inflammation of the inner lining of the abdominal wall and sepsis.
Appendicitis is primarily caused by a blockage of the hollow portion in the appendix. This blockage typically results from a faecolith, a calcified "stone" made of feces. Some studies show a correlation between appendicoliths and disease severity. Other factors such as inflamed lymphoid tissue from a viral infection, intestinal parasites, gallstone, or tumors may also lead to this blockage. When the appendix becomes blocked, it experiences increased pressure, reduced blood flow, and bacterial growth, resulting in inflammation. This combination of factors causes tissue injury and, ultimately, tissue death. If this process is left untreated, it can lead to the appendix rupturing, which releases bacteria into the abdominal cavity, potentially leading to severe complications.
The diagnosis of appendicitis is largely based on the person's signs and symptoms. In cases where the diagnosis is unclear, close observation, medical imaging, and laboratory tests can be helpful. The two most commonly used imaging tests for diagnosing appendicitis are ultrasound and computed tomography. CT scan is more accurate than ultrasound in detecting acute appendicitis. However, ultrasound may be preferred as the first imaging test in children and pregnant women because of the risks associated with radiation exposure from CT scans. Although ultrasound may aid in diagnosis, its main role is in identifying important differentials, such as ovarian pathology in females or mesenteric adenitis in children.
The standard treatment for acute appendicitis involves the surgical removal of the inflamed appendix. This procedure can be performed either through an open incision in the abdomen or using minimally invasive techniques with small incisions and cameras. Surgery is essential to reduce the risk of complications or potential death associated with the rupture of the appendix. Antibiotics may be equally effective in certain cases of non-ruptured appendicitis, but 31% will undergo appendectomy within one year. It is one of the most common and significant causes of sudden abdominal pain. In 2015, approximately 11.6 million cases of appendicitis were reported, resulting in around 50,100 deaths worldwide. In the United States, appendicitis is one of the most common causes of sudden abdominal pain requiring surgery. Annually, more than 300,000 individuals in the United States undergo surgical removal of their appendix.

Signs and symptoms

The presentation of acute appendicitis includes acute abdominal pain, nausea, vomiting, and fever. As the appendix becomes more swollen and inflamed, it begins to irritate the adjoining abdominal wall. This leads the pain to localize at the right lower quadrant. This classic migration of pain may not appear in children under three years. This pain can be triggered by a sharp pain feeling. Pain from appendicitis may begin as dull pain around the navel. After several hours, the pain usually migrates towards the right lower quadrant, where it becomes localized. Symptoms include localized findings in the right iliac fossa. The abdominal wall becomes very sensitive to gentle pressure. There is pain in the sudden release of deep tension in the lower abdomen. If the appendix is retrocecal, even deep pressure in the right lower quadrant may fail to elicit tenderness. This is because the cecum, distended with gas, protects the inflamed appendix from pressure. Similarly, if the appendix lies entirely within the pelvis, there is typically a complete absence of abdominal rigidity. In such cases, a digital rectal examination elicits tenderness in the rectovesical pouch. Coughing causes point tenderness in this area, called Dunphy's sign.

Causes

Acute appendicitis seems to be the result of a primary obstruction of the appendix. Once this obstruction occurs, the appendix becomes filled with mucus and swells. This continued production of mucus leads to increased pressures within the lumen and the walls of the appendix. The increased pressure results in thrombosis and occlusion of the small vessels, and stasis of lymphatic flow. At this point, spontaneous recovery rarely occurs. As the occlusion of blood vessels progresses, the appendix becomes ischemic and then necrotic. As bacteria begin to leak out through the dying walls, pus forms within and around the appendix. The result is appendiceal rupture causing peritonitis, which may lead to sepsis and in rare cases, death. These events are responsible for the slowly evolving abdominal pain and other commonly associated symptoms.
The causative agents include bezoars, foreign bodies, trauma, lymphadenitis and, most commonly, calcified fecal deposits that are known as appendicoliths or fecaliths. The occurrence of obstructing fecaliths has attracted attention since their presence in people with appendicitis is higher in developed than in developing countries. In addition, an appendiceal fecalith is commonly associated with complicated appendicitis. Fecal stasis and arrest may play a role, as demonstrated by people with acute appendicitis having fewer bowel movements per week compared with healthy controls.
The occurrence of a fecalith in the appendix was thought to be attributed to a right-sided fecal retention reservoir in the colon and a prolonged transit time. However, a prolonged transit time was not observed in subsequent studies. Diverticular disease and adenomatous polyps were historically unknown and colon cancer was exceedingly rare in communities where appendicitis itself was rare or absent, such as various African communities. Studies have implicated a transition to a Western diet lower in fiber in rising frequencies of appendicitis as well as the other aforementioned colonic diseases in these communities, and acute appendicitis has been shown to occur antecedent to cancer in the colon and rectum. Several studies offer evidence that a low fiber intake is involved in the pathogenesis of appendicitis. This low intake of dietary fiber is in accordance with the occurrence of a right-sided fecal reservoir and the fact that dietary fiber reduces transit time.

Diagnosis

The physician will ask questions to get the health history, assess the patient's symptoms, do a complete physical exam, and order both laboratory and imaging tests. Appendicitis symptoms fall into two categories, typical and atypical.
Typical appendicitis is characterized by a migratory right iliac fossa pain associated with nausea, and anorexia, which can occur with or without vomiting and localized muscle stiffness/ generalized guarding. It is possible the pain could localize to the left lower quadrant in people with situs inversus totalis. The combination of migrated umbilical pain to the right lower quadrant, loss of appetite for food, nausea, unsustained vomiting, and mild fever is classic.
Atypical histories lack this typical progression and may include pain in the right lower quadrant as an initial symptom. Irritation of the peritoneum can lead to increased pain on movement, or jolting, for example going over speed bumps. Atypical histories often require imaging with ultrasound or CT scanning.

Signs

During the early stages of appendicitis diagnosis, it is common for physical exams to present inconspicuous findings. Signs of inflammation become noticeable as the disease progresses. These signs may include
  • Aure-Rozanova's sign: Increased pain on palpation with a finger in the right inferior lumbar triangle.
  • Bartomier-Michelson's sign: Increased pain on palpation at the right iliac region as the person being examined lies on their left side compared to when they lie on their back.
  • Dunphy's sign: Increased pain in the right lower quadrant by coughing.
  • Hamburger sign: The patient refuses to eat
  • Kocher's sign : From the person's medical history, the start of pain in the umbilical region with a subsequent shift to the right iliac region.
  • Massouh's sign: Developed in and popular in southwest England, the examiner performs a firm swish with their index and middle finger across the abdomen from the xiphoid process to the left and the right iliac fossa.
  • Obturator sign: The person being evaluated lies on her or his back with the hip and knee both flexed at ninety degrees. The examiner holds the person's ankle with one hand and knee with the other hand. The examiner rotates the hip by moving the person's ankle away from their body while allowing the knee to move only inward. A positive test is pain with internal rotation of the hip.
  • Psoas sign, also known as "Obraztsova's sign", is right lower-quadrant pain that is produced with either the passive extension of the right hip or by the active flexion of the person's right hip while supine. The pain that is elicited is due to inflammation of the peritoneum overlying the iliopsoas muscles and inflammation of the psoas muscles themselves. Straightening out the leg causes pain because it stretches these muscles while flexing the hip activates the iliopsoas and causes pain.
  • Rovsing's sign: Pain in the lower right abdominal quadrant with continuous deep palpation starting from the left iliac fossa upwards. The thought is there will be increased pressure around the appendix by pushing bowel contents and air toward the ileocaecal valve provoking right-sided abdominal pain.
  • Rosenstein's sign : Increased pain in the right iliac region as the person is being examined lies on their left side.
  • Perman's sign: In acute appendicitis palpation in the left iliac fossa may produce pain in the right iliac fossa.

    Laboratory tests

While there is no laboratory test specific for appendicitis, a complete blood count is done to check for signs of infection or inflammation. Although 70–90 percent of people with appendicitis may have an elevated white blood cell count, many other abdominal and pelvic conditions can cause the WBC count to be elevated. However, a high WBC count may not alone represent a solid indicator of appendicitis but rather an inflammation but the neutrophil ratio was more sensitive and specific for acute appendicitis. Several routine and non-routine laboratory tests have been investigated for discriminating simple and complicated appendicitis, but their diagnostic accuracy is uncertain.
In children, neutrophil-lymphocyte ratio demonstrates a high degree of accuracy in the diagnosis of acute appendicitis and distinguishes complicated appendicitis from simple appendicitis. 75–78 percent of the patients have neutrophilia. Delta-neutrophil index is a valuable parameter that helps in the diagnosis of histologically normal appendicitis and distinguishing between simple and complicated appendicitis.
A will be ordered by the doctor to find out if there are any further causes of inflammation. The C-reactive protein/albumin ratio can be a reliable predictor of complicated appendicitis.
The urinalysis is important for ruling out a urinary tract infection as the cause of abdominal pain. The presence of more than 20 WBC per high-power field in the urine is more suggestive of a urinary tract disorder.
If the patient is a female, a pregnancy test will be ordered.