J. A. McKean1, S. Ayub1, D. Rajderkar1, M. M. Mustafa1, J. A. Taylor1, S. D. Larson1, S. Islam1 1University Of Florida,Pediatric Surgery,Gainesville, FL, USA
Introduction:
Abdominal pain in children is one of the most frequent causes of an emergency department (ED) visit. Ultrasound evaluation for appendicitis in that setting has become almost standard of care imaging to reduce radiation exposure from computed tomography. However, this has led to a practice that encourages indiscriminate use of ultrasound (US) and potentially reduces its effectiveness as a diagnostic tool. The purpose of this study was to better understand the utilization and predictive value of US for diagnosis of appendicitis in children.
Methods:
All children who underwent an ultrasound evaluation for abdominal pain in the ED over a 5-year period were included in the study. Patients having US for trauma, or for gallbladder disease were excluded. Data regarding clinical presentation, laboratory evaluation, imaging results, and outcomes were collected. The entire cohort was divided based on age, gender, appendicitis score (PAS), and US results and comparative statistics performed. Students t test, Fischer’s exact test, and the Mann-Whitney tests were performed where appropriate and a p value <0.05 was considered significant.
Results: 1650 patients were identified with US evaluation in the ED. A total of 746 children had evaluation for appendicitis. Overall mean age was 11 years, 50.8% were female, and the mean WBC count was 11.88/mm3. Seventy percent of the cohort had a moderate risk PAS score (4-7), while 21% were low risk and 9% were high risk. US results were 63.8% non-visualization (NV), 12.2% positive, and 23.9% negative for appendicitis; a definitive result on US was more likely during the daytime(P=0.002). Further analysis of the NV subset revealed no difference in age or gender, 74% had a moderate PAS score, and 22% underwent a subsequent CT scan. Table 1 shows the difference between NV US patients who were admitted for observation only, discharged from the ED, and who were admitted and underwent an appendectomy. Low risk PAS patients had a 60% NV US and 3% false positive rate. Patients with a high PAS had positive US diagnosis in 43% cases.
Conclusion:
US utilization for children with abdominal pain is high, even in the setting of a low PAS, where it was not useful. There was a likely reduction in CT scans for patients with a high PAS. Patients with a NV appendix were very common and the use of laboratory and clinical criteria as well as the C-reactive protein were helpful in management. These data will be used to help refine the US use in children in the ED.
