The prevalence of pathological findings identified by next day abdominal ultrasound in patients discharged from the emergency department

Objective: A common strategy for managing emergency department (ED) patients with low-risk abdominal pain is to discharge them home and arrange for next day outpatient ultrasound for further assessment. The objective was to determine the proportion of outpatient ultrasounds with findings requiring intervention within 14 days. Methods: This was a retrospective chart review of non-pregnant patients ages 18 to 40 years, presenting to an academic ED (annual census 65,000) with an abdominal complaint for whom the emergency physician arranged an outpatient (next day) abdominal ultrasound. Results: Of the 299 included patients, 252 (84.3%) were female and mean (SD) age was 28.4 (6.0) years. Twenty-three (7.7%) patients had ultrasounds requiring intervention within 14 days of imaging. Of these, eight (34.8%) had appendicitis, five (21.7%) had cholecystitis, four (17.4%) had urological pathology, three (13.0%) had gynecological pathology, and three (13.0%) had gastrointestinal diagnoses. Of note, 14 (60.9%) patients requiring follow-up or intervention within 14 days had symptoms that improved or resolved at the time of the outpatient ultrasound. For the 277 (92.6%) patients not requiring intervention, 117 (42.2%) had improved, 89 (32.1%) were unchanged, 50 (18.1%) had resolved, and 5 (1.8%) had worsened symptoms at the time of the follow-up ultrasound. Of the non-intervention patients, 13 (4.7%) went on to have alternative imaging, including magnetic resonance imaging, computed tomography, and a sonohysterogram. Conclusions: Next-day ultrasound imaging remains a good way of identifying patients with serious pathology not appreciated at the time of their ED visit.