Pediatric appendicitis in "real-time": the value of sonography in diagnosis and treatment.

OBJECTIVES

To determine the accuracy of sonography in the diagnosis of clinically equivocal appendicitis, and to identify the factors leading to an inaccurate ultrasound diagnosis. The impact of sonographic findings on clinical management and outcome of children with appendicitis is examined.

METHODS

We performed a retrospective review of 317 children who attended the emergency department (ED) of a children's hospital for acute abdominal pain for which acute appendicitis was the main differential diagnosis. They had ultrasound because the diagnosis was uncertain clinically.

RESULTS

The positive predictive value of ultrasound for appendicitis was 0.92, and the negative predictive value was 0.88. The sensitivity and specificity could not be determined because there were 43 patients with equivocal ultrasound results. The pitfalls hindering the accuracy of ultrasound diagnosis included a high incidence of perforated appendicitis at presentation, the retrocecal appendix, and other technical factors such as abdominal guarding, excessive bowel gas, obesity, inadequate bladder filling, and the uncooperative patient. When ultrasound findings were combined with clinical judgment in clinical management, there were only five cases of non-therapeutic laparotomy and eight cases of delayed surgery due to missed diagnosis in our cohort.

CONCLUSIONS

Ultrasound is a useful for the evaluation of acute abdominal pain in children. However, in the setting of a pediatric hospital ED, the accuracy of ultrasound and its ability to improve early hospital triage may be reduced. Repeated clinical review is still essential and in selected cases, appendiceal CT scan may be required to guide therapeutic decision making.