ABSTRACT
BACKGROUND: The efficacy of ultrasonography (US) and abdominal X-ray in combination with Pediatric Appendicitis Score (PAS) is complicated in the diagnosis of acute appendicitis. Abdominal X-ray is as useful as US with clinical assessment when evaluated by experienced pediatric radiologist in acute appendicitis. The aim of this study was to determine the value of US and abdominal X-ray for appendicitis in children when combined with clinical assessment based on PAS, and to establish a practical pathway for acute appendicitis in childhood. METHODS: A prospective, observational cohort study was conducted at an urban, academic pediatric emergency department. Patients were classified at low (PAS 1-4), intermediate (PAS 5-7), or high (PAS 8-10) risk for appendicitis. Low-risk patients were discharged with telephone follow-up in ≤10 days; those at intermediate risk underwent X-ray and US. High-risk patients received immediate surgical consultation. Patients were grouped on histopathology as having either proven acute appendicitis or no appendicitis. RESULTS: A total of 288 children were analyzed. Surgery was performed in 134 patients (46.5%), and 128 (95.5%) had positive histopathology. Mean PAS in the patients with and without appendicitis was 7.09 ± 1.42 and 4.97 ± 2.29, respectively (P = 0.00). The rate of missed cases was 6/288 (2%), and the negative appendectomy rate was 6/134 (4.4%). When the score cut-off was set at 6, the sensitivity and specificity of PAS was 86.7% and 63.1%, respectively. The diagnostic performance of daytime US had a sensitivity of 91.1% and specificity of 71.1%. Also, positive US or PAS >6 or both, had sensitivity and specificity 96.7% and 59.9%, respectively. CONCLUSION: US or abdominal X-ray in children with possible appendicitis should be integrated with PAS to determine the next steps in management. In the case of discordance between the clinical findings and radiology, prolonged observation or further imaging are recommended.