Abdominal pain is a common complaint in children and young adults, resulting in a significant number of visits to the hospital emergency department. Of all possible diagnoses associated with abdominal pain, acute appendicitis is the most serious and perhaps one of the most difficult to diagnose based solely on clinical findings. For more than 10 years, sonography has been considered an accurate diagnostic tool for examining patients with acute appendicitis. However, the role of sonography in the initial diagnosis of lower abdominal or pelvic pain has not been well researched. Carrico and colleagues evaluated the impact of sonography on physicians' initial diagnostic confidence and their treatment of nontraumatic abdominal pain in children and young adults.

Children and young adults who presented to a large urban pediatric emergency department during a six-month period in 1997 with acute abdominal pain, pelvic pain, or both, and who underwent sonographic examination were eligible for the study. Physicians were asked to state the most likely diagnosis and then estimate the probability of that diagnosis both before and after the results of sonography were available. They were also asked to describe their treatment plan if sonography had not been performed.

Of the 101 patients who met the study criteria, data were collected for 94. Sonographic data significantly affected the initial diagnosis in 38 patients who were thought to have appendicitis after clinical examination. Of these patients, 20 (53 percent) had a change in diagnosis after sonographic examination. The remainder of the total study group had abdominal conditions other than appendicitis. The use of sonography improved physicians' clinical confidence, particularly in those patients whose diagnoses changed after the procedure. In this group, there were no false-positive results, and the true negative rate was 100 percent. The treatment plans of 43 patients overall changed as a result of sonographic information. Before the sonography, physicians planned to discharge two and admit for observation 12 of the 17 patients with surgically proven appendicitis.

The authors conclude that sonography is an important tool in the assessment of abdominal or pelvic pain in children and young adults. Sonographic information changed initial diagnoses, increased clinical confidence and led to changes in treatment plans. In this study, the results of sonography reassured physicians that, in most instances, patients' abdominal pain did not require surgical intervention. For patients who had acute appendicitis, sonography reduced delays in diagnosis.