The influence of body mass index on the accuracy of ultrasound and computed tomography in diagnosing appendicitis in children

Use and accuracy of diagnostic imaging by hospital type in pediatric appendicitis

OBJECTIVE

Accurate, timely diagnosis of pediatric appendicitis minimizes unnecessary operations and treatment delays. Preoperative abdominal-pelvic computed tomography (CT) scan is sensitive and specific for appendicitis; however, concerns regarding radiation exposure in children obligate scrutiny of CT use. Here, we characterize recent preoperative imaging use and accuracy among pediatric appendectomy subjects.

METHODS

We retrospectively reviewed children who underwent operations for presumed appendicitis at a single tertiary-care children's hospital and examined preoperative CT and ultrasound use with subject characteristics. Preoperative imaging accuracy was compared with postoperative and histologic diagnosis as the reference standard.

RESULTS

Most children (395/423, 93.4%) who underwent an operation for appendicitis during 2009-2010 had preoperative imaging. Final diagnoses included normal appendix (7.3%) and perforated appendicitis (23.6%). In multivariable analysis, initial evaluation at a community hospital versus the children's hospital was associated with 4.4-fold higher odds of obtaining a preoperative CT scan (P = .002), whereas preoperative ultrasound was less likely (odds ratio 0.20; P = .003). Ultrasound and CT sensitivities for appendicitis were diminished for studies performed at community hospitals compared with the children's hospital. Girls were 4.5-fold more likely to undergo both ultrasound and CT scans and were associated with lower ultrasound sensitivity for appendicitis.

CONCLUSIONS

Widespread preoperative imaging did not eliminate unnecessary pediatric appendectomies. Controlling for factors potentially associated with referral bias, a CT scan was more likely to be performed in children initially evaluated at community hospitals compared with the children's hospital. Broadly-applicable strategies to systematically maximize diagnostic accuracy for childhood appendicitis, while minimizing ionizing radiation exposure, are urgently needed.

Increased incidence of perforated appendicitis in children with obesity

Based on their clinical impression, the authors hypothesized that children with obesity may more commonly present with perforated appendicitis. Therefore, the authors reviewed their experience from 2008 to 2010 to determine whether obesity affected the clinical presentation of appendicitis. Variables studied were height, weight, use of diagnostic imaging, and clinical findings of appendicitis at presentation. Outcomes assessed were length of stay and complication rate. The study identified 319 patients with appendicitis. Children with obesity were more likely (P = .026) to present with perforation (28/62, 45%) than nonobese patients (78/257, 30%). Neither length of stay nor complication rate was affected by the presence of obesity. The data suggest that children with obesity are more likely to present with perforated appendicitis. This finding suggests that the diagnosis of appendicitis may be more difficult in obese patients or their presentation may be delayed. Practitioners should have heightened awareness in children with obesity and symptoms of abdominal pain.

Diagnosis and management of pediatric appendicitis, intussusception, and Meckel diverticulum

Three of the most common causes of surgical abdominal pain in pediatric patients include appendicitis, Meckel diverticulum, and intussusception. All 3 can present with right lower quadrant pain, and can lead to significant morbidity and even mortality. Although ultrasound is the preferred method of diagnosis with appendicitis and intussusception, considerable variety exists in the modalities needed in the diagnosis of Meckel diverticulum. This article discusses the pathways to diagnosis, the modes of treatment, and the continued areas of controversy.