The role of plain radiographs in patients with acute abdominal pain at the ED

Objective: The purpose of this study was to evaluate the added value of plain radiographs on top of clinical assessment in unselected patients presenting with acute abdominal pain at the emergency department (ED).

Methods: In a multicenter prospective trial, patients with abdominal pain more than 2 hours and less than 5 days presented at the ED were evaluated clinically, and a diagnosis was made by the treating physician. Subsequently, all patients underwent supine abdominal and upright chest radiographs, after which the diagnosis was reassessed by the treating physician. A final (reference) diagnosis was assigned by an expert panel. The number of changes in the primary diagnosis, as well as the accuracy of these changes, was calculated. Changes in the level of confidence were evaluated for unchanged diagnoses.

Results: Between March 2005 and November 2006, 1021 patients, 55% female, mean age 47 years (range, 19-94 years), were included. In 117 of 1021 patients, the diagnosis changed after plain radiographs, and this change was correct in 39 patients (22% of changed diagnoses and 4% of total study population). Overall, the clinical diagnosis was correct in 502 (49%) patients. The diagnosis after evaluation of the radiographs was correct in 514 (50%) patients, a nonsignificant difference (P = .14). In 65% of patients with unchanged diagnosis before and after plain radiography, the level of confidence of that diagnosis did not change either.

Conclusion: The added value of plain radiographs is too limited to advocate their routine use in the diagnostic workup of patients with acute abdominal pain, because few diagnoses change and the level of confidence were mostly not affected.