Management of appendicitis in pediatric patients

1. Appendicitis: Surgical Perspective
INTRODUCTION
Appendicitis is one of the most common surgical conditions in the pediatric patient.
History of the Procedure: Many early reports exist of inflammation in and around the
appendix, but Reginald Fitz, in 1886, first provided an accurate description of the
disease process. He clearly described the clinical history, physical findings, and
pathology and also was the first to advocate appendectomy as the cure.
Although Thomas Morton is credited with the first successful appendectomy in the
United States in 1887, one of the first surgeons to correctly diagnose acute appendicitis,
perform an appendectomy, have the patient recover, and report his experience was
Senn in 1889. This was also the year that McBurney described the clinical findings of
acute appendicitis, including the point of maximal tenderness, which bears his name.
Problem: Appendicitis may be a significant source of morbidity.
Frequency: Individuals have approximately a 7% risk of developing appendicitis during
their lifetime. Appendicitis is much more common in developed countries. Although the
reason for this discrepancy is unknown, potential risk factors include a diet low in fiber
and high in sugar, family history, and infection.
The peak incidence of appendicitis is in children aged 10-12 years; thereafter, the
incidence continues to decline, although appendicitis occurs in adulthood and into old
age. The lowest incidence of appendicitis is in infancy.
Pathophysiology: Appendicitis is most often due to luminal obstruction followed by
presumed bacterial invasion. In children, obstruction is usually due to lymphoid
hyperplasia of the submucosal follicles. The cause of this hyperplasia is controversial,
but dehydration and a viral infection have been proposed. Another common cause of
obstruction of the appendix is a fecalith. Other rare causes include foreign bodies,
parasitic infections, and inflammatory strictures.
Luminal obstruction and mucus production result in increased intraluminal pressure.
Bacteria trapped within the appendiceal lumen begin to multiply, and the appendix
becomes distended. Venous congestion and edema follow next, and by 12 hours after
onset, the inflammatory process may become transmural. Peritoneal irritation then
develops. If the obstruction is left untreated, arterial blood flow to the appendix is
compromised, and this leads to tissue ischemia. Full thickness necrosis of the
appendiceal wall leads to perforation with the release of fecal and suppurative contents
into the peritoneal cavity. Depending on the duration of the disease process, either a
localized walled-off abscess occurs, or if the pathologic process has advanced rapidly,
the perforation is free in the peritoneal cavity and generalized peritonitis occurs.
Clinical:

2. Acute appendicitis
A history of periumbilical pain followed by anorexia or nausea is typical, followed by the
development of localized right lower quadrant pain. Unfortunately, fewer than half of the
children present with this classic combination of signs and symptoms. The length of the
illness is usually less than 24-36 hours.
All patients with appendicitis have abdominal pain and many have anorexia; absence of
both of these findings should place the diagnosis of appendicitis in question. The child
who states that riding in a vehicle was painful when the vehicle hit the bumps in the road
on the way to the hospital may have peritoneal irritation.
Atypical pain is common and occurs in 40-45% of patients. This includes children who
initially have localized pain and those with no visceral symptoms.
Physical examination helps to distinguish appendicitis from other abdominal diseases.
Examination of the child requires skill, patience, and warm hands. Initial and continued
observation of the child is of critical importance. An ill-appearing quiet child who is lying
very still in bed, perhaps with his or her legs flexed, is much more concerning than a
child who is laughing, playing, and walking around the room. The examination should be
thorough and start with areas other than the abdomen. Because lower lobe pneumonias
can cause abdominal findings, a history of such should be elicited and a thorough chest
examination performed.
Begin examination of the abdomen by asking the child to point with one finger to the site
of maximal pain. Palpate the abdomen at a site distant to this, with the most tender area
examined last. A particularly anxious child may be palpated with a stethoscope.
Distracting questions concerning school and family members may be helpful to relieve
anxiety during the examination. Observing the child's facial expressions during this
questioning and palpating is critical.
During the abdominal examination, try to avoid eliciting rebound tenderness. This is a
painful practice and certainly destroys any trust that has been garnered during the
examination. Other methods can be used to establish that the patient has peritoneal
irritation. Asking the patient to jump up and down or to bounce his or her pelvis off the
bed while in the supine position may elicit pain in the presence of peritoneal irritation.
Alternatively, other acceptable maneuvers are tapping the patient's soles and shaking
the stretcher.
The digital rectal examination can be helpful in establishing the correct diagnosis,
especially in sexually active teenage females. The child should be told that the
examination is uncomfortable but should not cause sharp pain. The rectal examination is
particularly important in the child with a pelvic appendix in whom the findings on the
abdominal examination for appendicitis may be equivocal and indicative of peritoneal
irritation. During the examination, one may elicit pain during palpation of the right side of
the pelvis or one may feel a pelvic mass, which is more important when perforated
appendicitis is suspected.
Perforated appendicitis
A thorough history and physical examination is again paramount for a correct diagnosis.

3. Certain features of a child's presentation may suggest a perforated appendix. A child
younger than 6 years with symptoms for more than 48 hours is much more likely to have
a perforated appendix. The child may have generalized abdominal pain and may have a
temperature higher than 38°C. Examination of the abdomen may reveal generalized
peritonitis or a tender right lower quadrant mass. Younger children are much more likely
to present with diffuse abdominal pain and peritonitis, perhaps because their omentum is
not well developed and cannot contain the perforation.
INDICATIONS
Appendectomy is indicated once the diagnosis of appendicitis or perforated appendicitis
has been made. An exception would be a well-localized appendiceal perforation in a
child who is clinically well. This presentation allows initial nonoperative treatment with
definitive treatment months later with an interval appendectomy .
RELEVANT ANATOMY AND CONTRAINDICATIONS
Relevant Anatomy: The vermiform appendix is located in the right lower quadrant,
arises from the cecum, and is generally 5-10 cm in length. The appendix is lined by
typical colonic epithelium. The submucosa contains lymphoid follicles, which are very
few at birth. This number gradually increases to a peak of about 200 follicles in persons
aged 10-20 years. In persons older than 30 years, less than one half that number is
present, and the number continues to decrease throughout adulthood.
The relation of the base of the appendix to the cecum is constant, but the tip may be
found in a variety of locations. Note that the anatomic position of the appendix
determines the symptoms and the site of tenderness when the appendix becomes
inflamed.
Contraindications: Almost no contraindications exist to the surgical treatment of
appendicitis. However, note that certain patients with unrecognized perforated
appendicitis may present in a state florid septic shock. In these patients, and even in
those not so ill, one must ensure that the patient is adequately fluid resuscitated and is
administered appropriate broad-spectrum antibiotics prior to proceeding to the operating
room.