M. MacRae1, S. Patel1, T. McCallin3, S. Berlin4, E. Miyasaka2 1Case Western Reserve University School Of Medicine, Cleveland, OH, USA 2University Hospitals, Pediatric Surgery, Cleveland, OH, USA 3University Hospitals, Pediatric Emergency Medicine, Cleveland, OH, USA 4University Hospitals, Pediatric Radiology, Cleveland, OH, USA
Introduction: Diagnosis of acute appendicitis remains challenging due to variable clinical presentations, inconsistent visualization by ultrasound (US). US accuracy is dependent on the operator and location of the appendix, contributing to a high non-visualization (NVA) rate of up to 80%. Patients with NVA often undergo a secondary computed tomography (CT) scan to properly visualize the appendix, leading to increased exposure of children to ionizing radiation. As part of a multidisciplinary process improvement program, our institution implemented additional education for US technologists on appendix location and re-positioning techniques to better scan retrocecal areas. To better select patients for US, the protocol incorporated a modified pediatric appendicitis score (PAS) inclusive of c-reactive protein (CRP) levels (PAS+CRP) into the US technologist education to identify high-risk patients. The primary objective of this study is to evaluate changes in NVA and use of secondary CT scan in the ED.
Methods: The new protocol, including US technologist education, was implemented in June 2023. Between June 2023 and June 2024, 146 patients with abdominal pain in whom acute appendicitis was on the differential diagnosis were evaluated under the new protocol. A PAS+CRP score was calculated for all patients by adding 1 point to the traditional PAS for CRP>0.1 mg/dL, and 2 points for CRP>1 (total score 0-12). Patients with a score of 0-5 were categorized as low risk, 6-8 moderate risk, and 9-12 high risk. Rates of US and CT utilization and appendix identification by US were compared to rates at our institution prior to the protocol implementation (2017-2021). Descriptive statistics were obtained and comparisons between groups were performed using chi-squared and Fisher exact tests.
Results: NVA by ultrasound improved by 14% (75% pre-protocol vs 61% post-protocol, p<.0005). Overall CT use decreased by 15% (27% vs 12%, p<0.0002) and secondary CT utilization after non-visualization by US decreased by 11% (29% vs 18%, p<0.03). In patients deemed “high risk” by the PAS+CRP, NVA by US was 60.5% pre-protocol, compared to 50% post-protocol (p=0.49).
Conclusion: Our findings show that the multidisciplinary (surgery/ED/radiology) education protocol was associated with improved appendix visualization by US and decreased CT scan use in the diagnosis of pediatric acute appendicitis. Additional focus on improving the visualization of appendices in high risk patients would likely lead to improved diagnostic yield of US in this patient population.