Chapter 4 Appendicitis and Appendectomy
PATHOPHYSIOLOGY
Appendicitis is the most common condition requiring emergency abdominal surgery during childhood. Acute appendicitis is caused by the obstruction of the appendiceal lumen, resulting in compression of the blood vessels. Obstruction of the lumen can be caused by hyperplasia of the submucosal lymphoid tissue, appendiceal fecaliths, foreign bodies, and/or parasites. Bacteria then invade the layers of the appendiceal wall, causing local inflammation (acute appendicitis). Perforated appendicitis occurs when the inflamed wall becomes necrotic and “bursts” (perforates), resulting in peritonitis. In most cases, no definitive cause can be identified at the time of surgery. The prognosis is excellent, especially when surgery is performed before perforation occurs.
INCIDENCE
1. Approximately 80,000 children experience appendicitis per year.
2. Occurs in 1 per 1000 children younger than 14 years old
3. Incidence highest in later childhood, age 10 to 12 years.
4. Occurrence is unusual in children younger than 4 years of age and is rare in children younger than 1 year old.
5. Likelihood of perforation is related to age—it occurs more frequently in younger children, most probably because of difficulty in diagnosis.
CLINICAL MANIFESTATIONS
5. Decreased or absent bowel sounds
7. Diarrhea (small, watery evacuations)
LABORATORY AND DIAGNOSTIC TESTS
1. Complete blood count—leukocytosis, neutrophilia, absence of eosinophils
2. Urinalysis—to exclude urinary tract infection
3. Abdominal radiographic study—concave curvature of spine to right, calcified fecaliths
4. Ultrasonography (test of choice)—noncalcified fecaliths, nonperforated appendix, appendiceal abscess
5. Computed tomographic (CT) scan of abdomen—provides differential diagnosis for abdominal pain
