Uniformed Services University of the Health Sciences, San Antonio, TX (Drs. Stull and Hale); Uniformed Services University of the Health Sciences, Bethesda, MD (Dr. Servey) jessica.servey@usuhs.edu
The authors reported no potential conflict of interest relevant to this article.
The views expressed here are those of the authors and do not reflect the official views or policy of the Department of Defense or the US government.
Which clinical findings most reliably point to appendicitis? How do the 3 primary clinical scoring systems compare? When is it time to order imaging studies?
› Use the Alvarado Score, Pediatric Appendicitis Score, or Appendicitis Inflammatory Response Score to help rule out appendicitis and thereby reduce unnecessary imaging. A
› Choose ultrasound first as the imaging procedure for children and pregnant women, followed by magnetic resonance imaging if needed, to reduce ionizing radiation in these populations. B
› Consider an antibiotic-based strategy under the care of a surgeon in lieu of immediate surgery for uncomplicated appendicitis. A
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence B Inconsistent or limited-quality patient-oriented evidence C Consensus, usual practice, opinion, disease-oriented evidence, case series
References
CASE
A 35-year-old man with a body mass index of 20 presented to the emergency department after 24 hours of abdominal pain that began in the periumbilical region and then migrated to the right lower quadrant. The pain was exacerbated during ambulation and was intense when the car transporting him to the hospital encountered bumps in the road. After his pain started, he had associated anorexia, followed by nausea and emesis. He reported fever and chills. On examination, his temperature was 100.8 °F (38.2 °C), and palpation of the right and left lower quadrants elicited right lower quadrant pain. Laboratory evaluation revealed a white blood cell (WBC) count of 14,000 cells/mcL with 85% neutrophils, C-reactive protein of 40 mg/L, and a negative urinalysis.
How would you proceed with this patient?
Acute appendicitis is the most common cause of abdominal pain resulting in the need for surgical treatment; lifetime risk of appendicitis is 6% to 7%.1 Appendicitis is caused by intraluminal obstruction in the appendix from enlarged lymphoid tissue or a fecalith. The obstruction leads to elevated intraluminal pressure due to persistent mucus and gas production by bacteria, ultimately leading to ischemia and perforation.1 Additionally, obstruction leads to bacterial overgrowth, most commonly colonic flora such as Escherichia coli, Bacteroides fragilis, Streptococcus viridans, Enterococcus sp., Pseudomonas aeruginosa,and Klebsiella pneumoniaei.1,2
The following review provides a look at how 3 clinical scoring systems compare in the identification of acute appendicitis and details which imaging studies you should order—and when. But first, we’ll quickly detail the relevant physical findings and lab values that point to a diagnosis of acute appendicitis.
Physical findings.The patient typically first experiences vague abdominal pain that then localizes to the right lower quadrant due to peritoneal inflammation. Anorexia and nausea typically follow the abdominal pain. On examination, the patient often appears ill and exhibits abdominal guarding due to peritonitis. Tachycardia and fever are common; however, the absence of either does not exclude appendicitis. Classically, on palpation, the patient will have pain at McBurney’s point (one-third the distance from the anterior iliac spine to the umbilicus). The exact point of maximal tenderness can differ because of the varying anatomy of the appendix (retrocecal, paracolic, pelvic, pre/post ileal, promontoric, or subcecal).1 Right lower quadrant pain, abdominal rigidity, and radiation of periumbilical pain to the right lower quadrant are the most accurate findings in adults to rule in appendicitis.3 For children, physical exam findings have the highest likelihood in predicting appendicitis and include a positive Obturator sign, positive Rovsing sign, or a positive Psoas sign, and absent or decreased bowel sounds.4
Laboratory studies can support a diagnosis of appendicitis but cannot exclude it. Leukocytosis with neutrophil predominance is present in 90% of cases.5 An elevated C-reactive protein level renders the highest diagnostic accuracy.5 Perform a pregnancy test for any woman of child-bearing age, to assist in the diagnosis and guide imaging choices for evaluation. Additional laboratory tests are not needed unless there are concerns about volume depletion.
Clinical scoring systems
Several clinical scoring systems (TABLE6-10) have been validated to aid clinicians in evaluating patients with possible appendicitis, to decrease unnecessary exposure to ionizing radiation from computed tomography (CT) scans, to identify and reassure patients with low likelihoods of appendicitis, and to conduct outpatient follow-up.
