How Often Does Appendicitis Perforate?

Patient Presentation

A 3-year-old male was transferred after 24 hours of abdominal pain, diarrhea and emesis. He had at least 15 loose-watery yellow stools without blood over the past 12 hours but these seem to be decreasing more recently.
The emesis occurred 3-4 times with the last emesis about 4 hours ago. The emesis is yellow stomach contents.
The abdominal pain is described as being in the lower abdomen.
His mother also noted that in the past few hours he has had decreased urine output.
The review of systems was negative.
In the local emergency room he was noted to have a temperature of 101.9 degrees F, laboratories consistent with moderate dehydration, and air fluid levels on the abdominal radiograph. The complete blood count showed white blood cells of 13.5 x 1000/mm2 and a urinalysis with 10 white blood cells/high power field.
The pertinent physical exam shows a tired preschooler in mild pain. Temperature is 101.5 degrees F and other vital signs are normal. Lungs are clear to ausculatation and percussion. Abdominal examination shows mild distention, slightly decreased bowel sounds,
tender to minimal touch with no guarding or localization. Rectal examination showed pain and a mass in the right lower quadrant. Genitourinary examination reveals no inguinal hernia. The remainder of his examination was normal.
The repeated laboratory evaluation shows a complete blood count of 16.2 x 1000/mm2.
The radiological evaluation was a repeated abdominal radiographs demonstrating multiple dilated loops of small bowel with air fluid levels. There is also a suggestion of a soft tissue fullness in the right lower quadrant which is displacing the bowel
(see Figure 15). The patient was taken to the operating room where an exploratory laparotomy revealed the diagnosis of a ruptured appendix and pus surrounding
the appendix. An appendectomy and decontamination of the abdomen were performed. He was placed on intravenous antibiotics.
His clinical course over the next few days showed that he had a decreasing fever curve on antibiotics for 5 days. He was discharged home on day 6 off of antibiotics.

Figure 15 – Supine (left) and upright (right) radiographs of the abdomen
demonstrate multiple dilated loops of small bowel with air fluid levels. There is also a
suggestion of a soft tissue fullness in the right lower quadrant which is displacing the bowel
loops centrally.

Appendicitis results from a closed loop obstruction of a blind-ending tubular structure arising from the cecum. It is a common cause of abdominal pain. It is the most frequent condition leading to emergent abdominal surgery in pediatrics. The combination of obstruction, edema, bacterial overgrowth, increased inflammatory process and increased intraluminal pressure leads to abdominal pain and possibly perforation.
Appendicitis occurs in all age groups but is rare in neonates. The peak age is 6-10 years old.

Classically appendicitis begins with the development of anorexia and periumbilical pain, followed by vomiting and right lower quadrant pain. However, this presentation occurs in < 60% of patients.
The periumbilical pain is often poorly defined but is often associated with anorexia that preceeds nausea and vomiting. After a few hours the pain shifts to the right lower quadrant and is generally more intense and pinpoint. Children will often be afebrile or have a low grade fever.

In contrast to appendicitis, abdominal pain with an acute onset occurs more in ischemic conditions such as torsion, volvulus, intussception, etc. Shifting of localized abdominal pain generally doesn’t occur in other abdominal conditions than appendicitis.

The physical examination often shows a child who prefers to lie still to minimize the peritoneal irritation. The exact location of the pain depends on the location of the appendix. Typically the maximal tenderness is at McBurney’s point in the right lower quadrant. Rovsing sign suggestions peritoneal irritation and is pain in the right lower quadrant when left-sided palpation occurs.
A psoas sign can be elicited by placing the child on the left side and hyperextending the right leg. The obturator sign is elicited by internal rotation of the right thigh in a flexed position. Pain with this movement is caused by an inflammed appendix or other mass overlying the psoas muscle.
A sharp pain when coughing in the right lower quadrant is also suggestive of peritoneal irritation. The rectal examination should be done last and can reveal right sided tenderness, a mass or impacted stool.

A complete blood count usually shows an elevated white blood cell count; more than 15 x 1000/mm2 WBCs may indicate a perforated appendix. Appendicitis may cause irritation of the bladder with some WBCs in the urine. More than 20 WBCs suggests a urinary tract infection. A normal urinanalysis generally is not helpful to include or exclude appendicits.
Electrolytes, renal function tests, liver function tests and human chronionic gonadotropic-beta subunit testing (beta – hCG) are often helpful for management and determining possible other abdominal pain etiologies.

Plain film radiographs generally are not helpful in the diagnosis of appendicitis. A calcified appendicolith may be seen and adds weight to the clinical diagnosis.
Ultrasound is an excellent imaging modality to diagnose appendicitis as it has an overall sensitivity of 85% and specificity of 94% and does not involve radiation. . A noncompressible dilated appendix is a strong indicator of nonperforated appendicitis. A periappendiceal phlegmom or abscess indicates performation. Ultrasound may also indicate other pathology such as mesenteric adenitis, or tubo-ovarian pathology.
Today, in many practices computed tomography is replacing ultrasound for the diagnosis of appendicitis as it is technically easier to perform, although it involves the use of ionizing radiation.

Treatment involves surgical excision (i.e. open or laproscopic), debridement, antibiotics, and supportive care. The most common organisms in appendicitis are E. coli, Bacteroids, Klebsiella, Enterococci, and Pseudomonas.
Prognosis is excellent but complications such as performation, sepsis, shock and dehiscence occur. Overall mortality is 0.1 – 1%.

Failure to diagnose appendicitis is the second most common cause of failure to diagnose pediatric malpractice claims (meningitis is the first). From 1985-2003 the overall number of closed cases for failure to diagnose was 1749. Of these, 78 were for appendicitis and 28 of these cases resulting in a claim paid. The average payment was $130,940.
Recommendations to decrease the risk of a malpractice claim are to conduct and document a through history and physical examination (especially of the abdomen and genitals), consider observing the child in the office or emergency room and performing serial examinations, and explaining to the parents why you don’t think that this is appendicitis CURRENTLY but if the patient’s condition changes that they should call or return promptly. Parents should also receive clear discharge instructions and the instructions should be documented in the medical record.
Appropriate follow-up should be arranged often within a few hours.

Children should have nausea, vomiting and diarrhea to be diagnosed with gastroenteritis. Remember that children less than 3 years will often present with diarrhea when they have appendicitis also. This current patient was 3 years old and presented with diarrhea.

Learning Point
Overall, the prognosis of appendicitis is excellent but complications such as sepsis, shock and dehiscence and perforation occur. Overall mortality is 0.1 – 1%. Overall appendicitis performation rate is between 17-40% at diagnosis for all ages. The performation rate for children < 8 years old is twice that of children > 8 years old. Perforation is as high as 50-83% in preschool children.

Questions for Further Discussion
1. What is the differential diagnosis of abdominal pain?
2. What genitourinary problems need to be considered in a sexually-active adolescent patient with acute abdominal pain?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at Pediatric Common Questions, Quick Answers for this topic: Appendicitis.

Reynolds SL. Failure to Diagnose Appendicitis Among Top Medical Misadventures. AAP News. 2005;April:13.

Tucker J. Pediatrics, Appendicitis. eMedicine.
Available from the Internet at 6/4/2004, cited 4/21/2005).

Donna M. D’Alessandro, MD
Associate Professor of Pediatrics, Children’s Hospital of Iowa

May 23, 2005