The occurrence of fluid collections following routine abdominal surgical procedures: sonographic survey in asymptomatic postoperative patients.

To investigate the frequency and appearance of reactive effusions following abdominal surgery, a prospective real-time sonographic survey of 80 asymptomatic postoperative patients was conducted. Serial scans on the 4th, 8th, and 12th postoperative days disclosed localized abdominal fluid collections in 19% (15/80), 6% (5/80), and 2.5% (2/80) of cases, respectively. The only collection that enlarged was an abscess. Knowledge of the natural history of reactive postoperative effusions should help the ultrasonographer to detect pathologic fluid collections and abscesses in postsurgical patients.