APPENDICITIS

Appendicitis

Appendicitis is a condition characterized by inflammation of the appendix. It is classified as a medical emergency and many cases require removal of the inflamed appendix, either by laparotomy or laparoscopy. Untreated, mortality is high, mainly because of the risk of rupture leading to peritonitis and shock. Reginald Fitz first described acute and chronic appendicitis in 1886,^[2] and it has been recognized as one of the most common causes of severe acute abdominal pain worldwide. A correctly diagnosed non-acute form of appendicitis is knownas "rumbling appendicitis".The term "pseudoappendicitis" is used to describe a condition mimicking appendicitis^] It can be associated with Yersinia enterocolitica.

Signs and symptoms

Pain first, vomiting next and fever last has been described as the classic presentation of acute appendicitis. Pain starts mid-abdomen, and except in children below 3 years, tends to localize in the right iliac fossa in a few hours. This pain can be elicited through various signs and can be severe. Signs include localized findings in the right iliac fossa. The abdominal wall becomes very sensitive to gentle pressure (palpation). Also, there is severe pain on sudden release of deep pressure in the lower abdomen (rebound tenderness). In case of a retrocecal appendix, however, even deep pressure in the right lower quadrant may fail to elicit tenderness (silent appendix), the reason being that the cecum, distended with gas, prevents the pressure exerted by the palpating hand from reaching the inflamed appendix. Similarly, if the appendix lies entirely within the pelvis, there is usually 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 (McBurney's point) and this is the least painful way to localize the inflamed appendix. If the abdomen on palpation is also involuntarily guarded (rigid), there should be a strong suspicion of peritonitis, requiring urgent surgical intervention.

Pain is not typical in some people, who may only have lower right abdominal pain, and no mid-upper abdominal pain at the beginning. Often, the pain is not prominent in the elderly or children below 3 years old. Or the pain point moves to other locations, especially just below the liver in a pregnant woman. In this case, the inflamed appendix is pushed up by the enlarged uterus.

Causes

On the basis of experimental evidence, acute appendicitis seems to be the end result of a primary obstruction of the appendix lumen (the inside space of a tubular structure).^[10][11] Once this obstruction occurs, the appendix subsequently becomes filled with mucus and swells, increasing pressures within the lumen and the walls of the appendix, resulting in thrombosis and occlusion of the small vessels, and stasis of lymphatic flow. Rarely, spontaneous recovery can occur at this point. As the former 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 (suppuration). The end result of this cascade is appendiceal rupture (a 'burst appendix') causing peritonitis, which may lead to septicemia and eventually death.

The causative agents include foreign bodies, trauma, intestinal worms, lymphadenitis, and, most commonly, calcified fecal deposits known as appendicoliths or fecaliths^[12] The occurrence of obstructing fecaliths has attracted attention since their presence in patients with appendicitis is significantly higher in developed than in developing countries, and an appendiceal fecalith is commonly associated with complicated appendicitis.Also, fecal stasis and arrest may play a role, as demonstrated by a significantly lower number of bowel movements per week in patients with acute appendicitis compared with healthy controls.The occurrence of a fecalith in the appendix seems to be attributed to a right-sided fecal retention reservoir in the colon and a prolonged transit time.^[16] From epidemiological data, it has been stated that diverticular disease and adenomatous polyps were unknown and colon cancer exceedingly rare in communities exempt for appendicitis.^[17][18] Also, acute appendicitis has been shown to occur antecedent to cancer in the colon and rectum.^[19] Several studies offer evidence that a low fiber intake is involved in the pathogenesis of appendicitis^[20] .^[21][22] This is in accordance with the occurrence of a right-sided fecal reservoir and the fact that dietary fiber reduces transit time.

Diagnosis

Diagnosis is based on patient history (symptoms) and physical examination backed by an elevation of neutrophilic white blood cells. Histories fall into two categories, typical and atypical. Typical appendicitis usually includes abdominal pain beginning in the region of the umbilicus for several hours, associated with anorexia, nausea or vomiting. The pain then "settles" into the right lower quadrant, where tenderness develops. Atypical histories lack this typical progression and may include pain in the right lower quadrant as an initial symptom. Atypical histories often require imaging with ultrasound and/or CT scanning.^[24] A pregnancy test is vital in all women of child bearing age, as ectopic pregnancies and appendicitis present similar symptoms. The consequences of missing an ectopic pregnancy are serious, and potentially life threatening. Furthermore the general principles of approaching abdominal pain in women (in so much that it is different from the approach in men) should be appreciated.

Blood test

Urine test

X–Ray

Ultrasound

Computed tomography

Ultrasound and CT compared