Appendicitis

Definition

Definition of 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, 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 known as "rumbling appendicitis".

Symptoms

Symptoms of Appendicitis
Pain first, vomiting next and fever last has been described as the classic presentation of acute appendicitis. Since the innervation of the appendix enters the spinal cord at T12, the same level as the umbilicus, the pain begins mid-abdomen. Later, as the appendix becomes more inflamed and irritates the adjoining abdominal wall, it tends to localize over several hours into the right lower quadrant, except in children under three years. 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.

Causes

Causes of Appendicitis
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). 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 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. 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. Also, 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 is in accordance with the occurrence of a right-sided fecal reservoir and the fact that dietary fiber reduces transit time.

Diagnosis

Diagnosis of Appendicitis
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. 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.

1. Blood Test: Most patients suspected of having appendicitis would be asked to do a blood test. Half of the time, the blood test is normal, so it is not foolproof in diagnosing appendicitis.
2. Urine Test: A urine test in appendicitis is usually normal. It may, however, show blood if the appendix is rubbing on the bladder, causing irritation. A urine test or urinalysis is compulsory in women, to rule out pregnancy in appendicitis, as well to help ensure that the abdominal pain felt and thought to be acute appendicitis is not in fact, due to ectopic pregnancy.
3. X–Ray: In 10% of patients with appendicitis, plain abdominal x-ray may demonstrate hard formed feces in the lumen of the appendix (Fecolith). It is agreed that the finding of Fecolith in the appendix on X – ray alone is a reason to operate to remove the appendix, because of the potential to cause worsening symptoms. In this respect, a plain abdominal X-ray may be useful in the diagnosis of appendicitis, though plain abdominal x- ray is no longer requested routinely in suspected cases of appendicitis. An abdominal X – ray may be done with a barium enema contrast to diagnose appendicitis. Barium enema is whitish fluid that is passed up into the rectum to act as a contrast. It will usually fill the whole of the large bowel. In normal appendix, the lumen will be present and the barium fills it up and is seen when the x-ray film is shot. In appendicitis, the lumen of the appendix will not be visible on the barium film.
4. Ultrasound: Ultrasonography and Doppler sonography provide useful means to detect appendicitis, especially in children, and shows free fluid collection in the right iliac fossa, along with a visible appendix without blood flow in color Doppler. In some cases (15% approximately), however, ultrasonography of the iliac fossa does not reveal any abnormalities despite the presence of appendicitis. This is especially true of early appendicitis before the appendix has become significantly distended and in adults where larger amounts of fat and bowel gas make actually seeing the appendix technically difficult. Despite these limitations, sonographic imaging in experienced hands can often distinguish between appendicitis and other diseases with very similar symptoms, such as inflammation of lymph nodes near the appendix or pain originating from other pelvic organs such as the ovaries or fallopian tubes.

Treatment

Treatment of Appendicitis
Largely surgical, any conservative management is done at the threshold of operation theater as the acutely inflamed appendix is liable to rupture during such treatment.

The treatment begins by keeping the patient from eating or drinking in preparation for surgery. An intravenous drip is used to hydrate the patient. Antibiotics given intravenously such as cefuroxime and metronidazole may be administered early to help kill bacteria and thus reduce the spread of infection in the abdomen and postoperative complications in the abdomen or wound. Equivocal cases may become more difficult to assess with antibiotic treatment and benefit from serial examinations. If the stomach is empty (no food in the past six hours) general anaesthesia is usually used. Otherwise, spinal anaesthesia may be used.

Once the decision to perform an appendectomy has been made, the preparation procedure takes more or less one to two hours. Meanwhile, the surgeon will explain the surgery procedure and will present the risks that must be considered when performing an appendectomy. With all surgeries there are certain risks that must be evaluated before performing the procedures. However, the risks are different depending on the state of the appendix. If the appendix has not ruptured, the complication rate is only about 3% but if the appendix has ruptured, the complication rate rises to almost 59%. The most usual complications that can occur are pneumonia, hernia of the incision, thrombophlebitis, bleeding or adhesions. Recent evidence indicates that a delay in obtaining surgery after admission results in no measurable difference in patient outcomes.

Prognosis

Prognosis of Appendicitis
If your appendix is removed before it ruptures, you will likely get well very soon after surgery. If your appendix ruptures before surgery, you will probably recover more slowly, and are more likely to develop an abscess or other complications.

Prevention

Prevention of Appendicitis
There is no way to prevent appendicitis. However, appendicitis is less common in people who eat foods high in fiber, such as fresh fruits and vegetables.